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† Aid in quality of the 1-2 upshift. † Aid in the quality and timing of the 3-2 kick- down ranges.
When the manual valve is set to the DRIVE posi- tion and the transmission is in the first or second gear range, 1-2 shift control or “modulated throttle pressure” is supplied to the middle of the accumula- tor piston by the 1-2 shift control valve. During the
AUTOMATIC TRANSMISSION - 48RE
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is
1-2 upshift, this pressure is used to control the kick- down servo apply pressure that is needed to apply the kickdown and accumulator pistons. Thus, the 1-2
shift point “cushioned” and the quality is improved. During a WOT kickdown, kickdown pres- sure is applied between the kickdown valve and the 1-2 shift control valve. This additional pressure is directed to the 1-2 shift control’s spring cavity, add- ing to the spring load on the valve. The result of this increased “modulated” throttle pressure is a firmer WOT upshift.Fig.2641-2ShiftControlValve
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VALVE BODY (Continued) 2-3 SHIFT VALVEThe 2-3 shift valve mechanism (Fig. 265) consists of the 2-3 shift valve, governor plug and spring, and a throttle plug. After the 1-2 shift valve has com- pleted its operation and applied the front band, line pressure is directed to the 2-3 shift valve through the connecting passages from the 1-2 shift valve. The line pressure will then dead–end at land #2 until the 2-3
valve is ready to make its shift. Now that the vehicle is in motion and under acceleration, there is throttle pressure being applied to the spring side of the valve and between lands #3 and #4.As vehicle speed increases, governor pressure increases proportionately, until it becomes great enough to overcome the combined throttle and spring pressure on the right side of the valve. Since the throttle pressure end of the 2-3 shift valve is larger in diameter than the 1-2 shift valve, the 2-3 shift will always happen at a greater speed than the 1-2 shift. When this happens, the governor plug is forced against the shift valve moving it to the right. The shift valve causes land #4 to close the passage sup- plying throttle pressure to the 2-3 shift valve. With- out throttle pressure present in the circuit now, the governor plug will push the valve over far enough to bottom the valve in its bore. This allows land #2 to direct line pressure to the front clutch.
After the shift (Fig. 266), line pressure is directed to the release side of the kickdown servo. This releases the front band and applies the front clutch,
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shifting into third gear or direct drive. The rear clutch remains applied, as it has been in the other gears. During a manual “1” or manual “2” gear selection, line pressure is sent between the two lands of the 2-3 governor plug. This line pressure at the governor plug locks the shift valve into the sec- ond gear position, preventing an upshift into direct drive. The theory for the blocking of the valve is the same as that of the 1-2 shift valve.
If the manual “2” or manual “1” gear position is selected from the drive position, the PCM will con- trol the timing of the downshift by targeting for a high governor pressure. When a safe vehicle speed is reached, the PCM will switch to its normal con- trol governor curve and the downshift will occur.
3-4 SHIFT VALVE
The PCM energizes the overdrive solenoid during the 3-4 upshift (Fig. 267). This causes the solenoid check ball to close the vent port allowing line pres- sure from the 2-3 shift valve to act directly on the 3-4 upshift valve. Line pressure on the 3-4 shift valve overcomes valve spring pressure moving the valve to the upshift position (Fig. 268). This action exposes the feed passages to the 3-4 timing valve, 3-4 quick fill valve, 3-4 accumulator, and ultimately to the overdrive piston.
Fig.2652-3ShiftValve-BeforeShift
DR VALVE BODY (Continued)
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Fig.2662-3ShiftValve-AfterShift
Fig.2673-4ShiftValveBeforeShift
Fig.2683-4ShiftValveAfterShift
3-4 TIMING VALVE
The 3-4 timing valve is moved by line pressure coming through the 3-4 shift valve (Fig. 268) or the converter clutch valve. After the shift, the timing
valve holds the 2-3 shift valve in an upshift position. The purpose is to prevent the 2-3 valve from down- shifting while either the overdrive clutch or converter clutch is applied (Fig. 267).
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VALVE BODY (Continued) 3-4 QUICK FILL VALVEThe 3-4 quick fill valve provides faster engagement of the overdrive clutch during 3-4 upshifts. The valve temporarily bypasses the clutch piston feed orifice at the start of a 3-4 upshift (Fig. 267). This exposes a larger passage into the piston retainer resulting in a much faster clutch fill and apply sequence. The quick fill valve does not bypass the regular clutch feed ori- fice throughout the 3-4 upshift. Instead, once a pre- determined pressure develops within the clutch, the valve closes the bypass (Fig. 268). Clutch fill is then completed through the regular feed orifice.
THROTTLE VALVE
In all gear positions the throttle valve (Fig. 269) is being supplied with line pressure. The throttle valve meters and reduces the line pressure that now becomes throttle pressure. The throttle valve is moved by a spring and the kickdown valve, which is mechanically connected to the throttle. The larger the throttle opening, the higher the throttle pressure (to a maximum of line pressure). The smaller the throttle opening, the lower the throttle pressure (to a minimum of zero at idle). As engine speed increases, the increase in pump speed increases pump output. The increase in pressure and volume must be regu- lated to maintain the balance within the transmis- sion. To do this, throttle pressure is routed to the reaction area on the right side of the throttle pres- sure plug (in the regulator valve).
The higher engine speed and line pressure would open the vent too far and reduce line pressure too much. Throttle pressure, which increases with engine
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speed (throttle opening), is used to oppose the move- ment of the pressure valve to help control the meter- ing passage at the vent. The throttle pressure is combined with spring pressure to reduce the force of the throttle pressure plug on the pressure valve. The larger spring at the right closes the regulator valve passage and maintains or increases line pressure. The increased line pressure works against the reac- tion area of the line pressure plug and the reaction area left of land #3 simultaneously moves the regu- lator valve train to the right and controls the meter- ing passage.
The kickdown valve, along with the throttle valve, serve to delay upshifts until the correct vehicle speed has been reached. It also controls downshifts upon driver demand, or increased engine load. If these valves were not in place, the shift points would be at the same speed for all throttle positions. The kick- down valve is actuated by a cam connected to the throttle. This is accomplished through either a link- age or a cable. The cam forces the kickdown valve toward the throttle valve compressing the spring between them and moving the throttle valve. As the throttle valve land starts to uncover its port, line pressure is “metered” out into the circuits and viewed as throttle pressure. This increased throttle pressure is metered out into the circuits it is applied to: the 1-2 and 2-3 shift valves. When the throttle pressure is high enough, a 3-2 downshift will occur. If the vehicle speed is low enough, a 2-1 downshift will occur.
Fig.269ThrottleValve
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DR VALVE BODY (Continued) SWITCH VALVE
When the transmission is in Drive Second before the TCC application occurs (Fig. 270), the pressure regulator valve is supplying torque converter pres- sure to the switch valve. The switch valve directs this pressure through the transmission input shaft, into the converter, through the converter, back out between the input shaft and the reaction shaft, and back up to the switch valve. From the switch valve, the fluid pressure is directed to the transmission cooler, and lubrication pressure returns from the cooler to lubricate different portions of the transmis- sion.
Fig.270SwitchValve-TorqueConverterUnlocked
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VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
Once the TCC control valve has moved to the right (Fig. 271), line pressure is directed to the tip of the switch valve, forcing the valve to the right. The switch valve now vents oil from the front of the pis- ton in the torque converter, and supplies line pres- sure to the (rear) apply side of the torque converter piston. This pressure differential causes the piston to apply against the friction material, cutting off any further flow of line pressure oil. After the switch valve is shuttled right allowing line pressure to engage the TCC, torque converter pressure is directed past the switch valve into the transmission cooler and lubrication circuits.
Fig.271SwitchValve-TorqueConverterLocked
DR VALVE BODY (Continued) MANUAL VALVE
The manual valve (Fig. 272) is a relay valve. The purpose of the manual valve is to direct fluid to the correct circuit needed for a specific gear or driving range. The manual valve, as the name implies, is manually operated by the driver with a lever located on the side of the valve body. The valve is connected mechanically by either a cable or linkage to the gear- shift mechanism. The valve is held in each of its positions by a spring-loaded roller or ball that engages the “roostercomb” of the manual valve lever.
CONVERTER CLUTCH LOCK-UP VALVE
The torque converter clutch (TCC) lock-up valve controls the back (ON) side of the torque converter clutch. When the PCM energizes the TCC solenoid to engage the converter clutch piston, pressure is applied to the TCC lock-up valve which moves to the right and applies pressure to the torque converter clutch.
CONVERTER CLUTCH LOCK-UP TIMING VALVE
The torque converter clutch (TCC) lock-up timing valve is there to block any 4-3 downshift until the TCC is completely unlocked and the clutch is disen- gaged.
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SHUTTLE VALVE
The assembly is contained in a bore in the valve body above the shift valves. When the manual valve is positioned in the Drive range, throttle pressure acts on the throttle plug of the shuttle valve (Fig. 264) to move it against a spring, increasing the spring force on the shuttle valve. During a part or full throttle 1-2 upshift, the throttle plug is bottomed by throttle pressure, holding the shuttle valve to the right against governor pressure, and opening a by–pass circuit. The shuttle valve controls the qual- ity of the kickdown shift by restricting the rate of fluid discharge from the front clutch and servo release circuits. During a 3-2 kickdown, fluid dis- charges through the shuttle by-pass circuit. When the shuttle valve closes the by-pass circuit, fluid dis- charge is restricted and controlled for the application of the front band. During a 2-3 “lift foot” upshift, the shuttle valve by-passes the restriction to allow full fluid flow through the by-pass groove for a faster release of the band.
Fig.272ManualValve
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VALVE BODY (Continued) BOOST VALVEThe boost valve (Fig. 273) provides increased fluid apply pressure to the overdrive clutch during 3-4
upshifts (Fig. 274), and when accelerating in fourth gear. The boost valve also serves to increase line pressure during torque converter lock-up.Fig.273BoostValveBeforeLock-up
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REMOVAL
The valve body can be removed for service without
having to remove the transmission assembly.
The valve body can be disassembled for cleaning
and inspection of the individual components.
The only replaceable valve body components are: † Manual lever. † Manual lever washer, seal, E-clip, and shaft seal. † Manual lever detent ball. † Throttle lever. † Fluid filter. † Pressure adjusting screw bracket. † Governor pressure solenoid. † Governor pressure sensor (includes transmission † Converter and harness. † Governor housing gasket. † Solenoid case connector O-rings. (1) Shift transmission into NEUTRAL. (2) Raise vehicle. (3) Remove gearshift and throttle levers from shaft
clutch/overdrive solenoid assembly
temperature thermistor).
of valve body manual lever.
(4) Disconnect wires at solenoid case connector
(Fig. 275).
(5) Remove the transmission range sensor. (6) Position drain pan under transmission oil pan. (7) Remove transmission oil pan and gasket. (8) Remove fluid filter from valve body. (9) Remove bolts attaching valve body to transmis-
sion case.
(10) Lower valve body enough to remove accumu-
lator piston and springs.
(11) Work manual lever shaft and electrical con-
nector out of transmission case.
Fig.274BoostValveAfterLock-up
Fig.275TransmissionCaseConnector
1 - SOLENOID CASE CONNECTOR 2 - TRANSMISSION RANGE SENSOR
DR VALVE BODY (Continued)
(12) Lower valve body, rotate valve body away from case, pull park rod out of sprag, and remove valve body (Fig. 276).
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(5) Remove governor pressure solenoid by pulling it straight out of bore in governor body. Remove and discard solenoid O-rings if worn, cut, or torn.
(6) Remove small shoulder bolt that secures sole- noid harness case connector to 3-4 accumulator hous- ing (Fig. 277). Retain shoulder bolt. Either tape it to harness or thread it back into accumulator housing after connector removal.
(7) Unhook overdrive/converter solenoid harness
from 3-4 accumulator cover plate (Fig. 278).
Fig.277SolenoidHarnessCaseConnector
ShoulderBolt
1 - SOLENOID HARNESS CASE CONNECTOR 2 - 3-4 ACCUMULATOR HOUSING
Fig.276ValveBody
1 - VALVE BODY 2 - WIRE HARNESS 3 - PARK ROD 4 - GOVERNOR PRESSURE SOLENOID 5 - GOVERNOR PRESSURE SENSOR
DISASSEMBLY
CAUTION: Do not clamp any valve body component in a vise. This practice can damage the component resulting in unsatisfactory operation after assembly and installation. Do not use pliers to remove any of the valves, plugs or springs and do not force any of the components out or into place. The valves and valve body housings will be damaged if force is used. Tag or mark the valve body springs for refer- ence as they are removed. Do not allow them to become intermixed.
(1) Disconnect wires from governor pressure sen-
sor and solenoid.
(2) Remove screws attaching governor body and
retainer plate to transfer plate.
(3) Remove retainer plate, governor body and gas-
ket from transfer plate.
(4) Remove governor pressure sensor from gover-
nor body.
Fig.278SolenoidHarnessRouting
1 - OVERDRIVE/CONVERTER SOLENOID WIRE HARNESS 2 - 3-4 ACCUMULATOR COVER PLATE
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VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
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(8) Turn valve body over and remove screws that attach overdrive/converter solenoid assembly to valve body (Fig. 279).
(9) Remove solenoid and harness assembly from
valve body (Fig. 280).
(10) Remove boost valve cover (Fig. 281). (11) Remove boost valve retainer, valve spring and
boost valve (Fig. 282).
Fig.281BoostValveCoverLocation
1 - BOOST VALVE HOUSING AND COVER 2 - BOOST VALVE TUBE
Fig.279SolenoidAssemblyScrews
1 - OVERDRIVE/CONVERTER CLUTCH SOLENOID ASSEMBLY 2 - HARNESS
Fig.282BoostValveComponents
1 - SPRING AND VALVE RETAINER 2 - COVER SCREWS 3 - BOOST VALVE COVER 4 - BOOST VALVE PLUG 5 - BOOST VALVE 6 - BOOST VALVE SPRING
(12) Secure detent ball and spring with Retainer
Tool 6583 (Fig. 283).
Fig.280SolenoidAssembly
1 - GOVERNOR SOLENOID WIRES 2 - CONVERTER CLUTCH SOLENOID 3 - SOLENOID SCREWS 4 - GOVERNOR SENSOR WIRES 5 - OVERDRIVE SOLENOID 6 - HARNESS 7 - CASE CONNECTOR
Fig.283DetentBallSpring
1 - SPECIAL TOOL 6583 POSITIONED ON DETENT HOUSING
DR VALVE BODY (Continued)
(13) Remove park rod E-clip and separate rod from
manual lever (Fig. 284).
(14) Remove E-clip and washer that retains throt-
tle lever shaft in manual lever (Fig. 285).
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(15) Remove manual lever and throttle lever (Fig. 286). Rotate and lift manual lever off valve body and throttle lever shaft. Then slide throttle lever out of valve body.
(16) Position pencil magnet next to detent housing to catch detent ball and spring. Then carefully remove Retainer Tool 6583 and remove detent ball and spring (Fig. 287).
Fig.284ParkRod
1 - MANUAL LEVER 2 - E-CLIP 3 - PARK ROD
Fig.286ManualAndThrottleLever
1 - PARK ROD 2 - MANUAL LEVER ASSEMBLY 3 - THROTTLE LEVER
Fig.285ThrottleLeverE-ClipAndWasher
1 - THROTTLE LEVER SHAFT 2 - E-CLIP AND WASHER 3 - MANUAL SHAFT
Fig.287DetentBallAndSpring
1 - DETENT HOUSING 2 - DETENT SPRING 3 - DETENT BALL 4 - PENCIL MAGNET
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VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
(17) Remove screws attaching pressure adjusting screw bracket to valve body and transfer plate (Fig. 288). Hold bracket firmly against spring tension while removing last screw.
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(18) Remove adjusting screw bracket, line pressure adjusting screw, pressure regulator valve spring and switch valve spring (Fig. 289). Do not remove throttle pressure adjusting screw from bracket and do not disturb setting of either adjusting screw during removal.
Fig.288AdjustingScrewBracketFastener
1 - T25 TORX™ BIT 2 - REMOVE THESE SCREWS FIRST 3 - BRACKET 4 - BRACKET 5 - REMOVE THIS SCREW LAST
Fig.289AdjustingScrewBracket
1 - SWITCH VALVE SPRING 2 - LINE PRESSURE SCREW 3 - THROTTLE PRESSURE ADJUSTING SCREW 4 - ADJUSTING SCREW BRACKET 5 - PRESSURE REGULATOR VALVE SPRING
(19) Turn upper housing over and remove switch valve, regulator valve and spring, and manual valve (Fig. 290).
(20) Remove kickdown detent, kickdown valve, and
throttle valve and spring (Fig. 290).
(21) Loosen left-side 3-4 accumulator housing attaching screw about 2-3 threads. Then remove cen- ter and right-side housing attaching screws (Fig. 291).
(22) Carefully rotate 3-4 accumulator housing upward and remove 3-4 shift valve spring and con- verter clutch valve plug and spring (Fig. 292).
DR VALVE BODY (Continued)
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1 - UPPER HOUSING 2 - REGULATOR VALVE 3 - SWITCH VALVE 4 - REGULATOR VALVE SPRING 5 - KICKDOWN VALVE 6 - KICKDOWN DETENT 7 - THROTTLE VALVE AND SPRING
Fig.290UpperHousingControlValveLocations
8 - MANUAL VALVE 9 - 1-2 GOVERNOR PLUG 10 - GOVERNOR PLUG COVER 11 - THROTTLE PLUG 12 - 2-3 GOVERNOR PLUG 13 - SHUTTLE VALVE PRIMARY SPRING
Fig.291AccumulatorHousingScrewLocations
1 - LOOSEN THIS SCREW 2 - REMOVE THESE SCREWS 3 - 3-4 ACCUMULATOR HOUSING
Fig.2923-4ShiftAndConverterClutchValve
SpringsandPlug
1 - ACCUMULATOR HOUSING 2 - CONVERTER CLUTCH VALVE SPRING 3 - CLUTCH VALVE PLUG 4 - 3-4 SHIFT VALVE SPRING
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VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
DR
(23) Remove left-side screw and remove 3-4 accu-
mulator housing from valve body (Fig. 293).
(24) Bend back tabs on boost valve tube brace (Fig.
294).
(26) Turn valve body over so lower housing is fac- ing upward (Fig. 296). In this position, the two check balls in upper housing will remain in place and not fall out when lower housing and separator plate are removed.
(27) Remove screws attaching valve body lower housing to upper housing and transfer plate (Fig. 296). Note position of boost valve tube brace for assembly reference.
(28) Remove lower housing and overdrive separa-
tor plate from transfer plate (Fig. 296).
Fig.293AccumulatorHousing,ValveSprings,and
Plug
1 - 3-4 SHIFT VALVE SPRING 2 - CONVERTER CLUTCH VALVE SPRING AND PLUG 3 - 3-4 ACCUMULATOR HOUSING
Fig.295BoostValveTube
1 - BOOST VALVE TUBE 2 - LOWER HOUSING 3 - DISENGAGE THIS END OF TUBE FIRST 4 - UPPER HOUSING
Fig.294BoostValveTubeBrace
1 - BOOST VALVE TUBE 2 - TUBE BRACE (DOUBLE TAB)
(25) Remove boost valve connecting tube (Fig. 295). Disengage tube from upper housing port first. Then rock opposite end of tube back and forth to work it out of lower housing.
CAUTION: Do not use tools to loosen or pry the connecting tube out of the valve body housings. Loosen and remove the tube by hand only.
Fig.296LowerHousing
1 - LOWER HOUSING 2 - OVERDRIVE SEPARATOR PLATE 3 - TRANSFER PLATE AND UPPER HOUSING
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(33) Remove rear clutch and rear servo check balls location for
from transfer plate. Note check ball assembly reference (Fig. 300).
Fig.299UpperHousingSeparatorPlate
1 - TRANSFER PLATE 2 - UPPER HOUSING SEPARATOR PLATE 3 - FILTER SCREEN 4 - BRACE
Fig.300RearClutchandRearServoCheckBall
Locations
1 - REAR CLUTCH CHECK BALL 2 - REAR SERVO CHECK BALL 3 - TRANSFER PLATE
DR VALVE BODY (Continued)
(29) Remove the Number 10 check ball from the transfer plate (Fig. 297). The check ball is approxi- mately 4.8 mm (3/16 in.) in diameter.
(30) Remove transfer plate from upper housing
(Fig. 298).
(31) Turn transfer plate over so upper housing sep-
arator plate is facing upward.
(32) Remove upper housing separator plate from transfer plate (Fig. 299). Note position of filter in separator plate for assembly reference.
Fig.297Number10CheckBall
1 - NUMBER 10 CHECK BALL (3/169)
Fig.298TransferPlate
1 - UPPER HOUSING 2 - TRANSFER PLATE
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VALVE BODY (Continued) VALVE BODY UPPER HOUSINGDR
Fig.302ShuttleValveE-ClipAndSecondarySpring 1 - E-CLIP 2 - SECONDARY SPRING AND GUIDES 3 - SHUTTLE VALVE
(1) Note location of check balls in valve body upper housing (Fig. 301). Then remove the one large diam- eter and the five smaller diameter check balls.
(2) Remove governor plug and shuttle valve covers
(Fig. 303).
(3) Remove E-clip that secures shuttle valve sec-
ondary spring on valve stem (Fig. 302).
(4) Remove throttle plug, primary spring, shuttle valve, secondary spring, and spring guides (Fig. 303). (5) Remove boost valve retainer, spring and valve
if not previously removed.
(6) Remove throttle plug and 1-2 and 2-3 governor
plugs (Fig. 290).
(7) Turn upper housing around and remove limit
valve and shift valve covers (Fig. 304).
(8) Remove limit valve housing. Then remove retainer, spring, limit valve, and 2-3 throttle plug from limit valve housing (Fig. 304).
(9) Remove 1-2 shift control valve and spring (Fig.
304).
(10) Remove 1-2 shift valve and spring (Fig. 304). (11) Remove 2-3 shift valve and spring from valve
body (Fig. 304).
(12) Remove pressure plug cover (Fig. 304). (13) Remove line pressure sleeve, throttle pressure
plug and spring (Fig. 304).
Fig.301CheckBallLocationsInUpperHousing
1 - SMALL DIAMETER CHECK BALLS (5) 2 - LARGE DIAMETER CHECK BALL (1)
DR VALVE BODY (Continued)
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Fig.303ShuttleandBoostValveLocation
1 - SPRING 2 - RETAINER 3 - BOOST VALVE 4 - BOOST VALVE PLUG 5 - SPRING GUIDES 6 - E-CLIP 7 - SHUTTLE VALVE SECONDARY SPRING
8 - SHUTTLE VALVE COVER 9 - SHUTTLE VALVE 10 - SHUTTLE VALVE PRIMARY SPRING 11 - GOVERNOR PLUG COVER 12 - THROTTLE PLUG 13 - UPPER HOUSING 14 - BOOST VALVE COVER
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VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
DR
Fig.304UpperHousingShiftValveandPressurePlugLocations
1 - UPPER HOUSING 2 - 1-2 SHIFT VALVE AND SPRING 3 - 2-3 SHIFT VALVE AND SPRING 4 - 2-3 THROTTLE PLUG 5 - LIMIT VALVE HOUSING 6 - LIMIT VALVE COVER
7 - LIMIT VALVE AND SPRING 8 - RETAINER 9 - 1-2 SHIFT CONTROL VALVE AND SPRING 10 - PRESSURE PLUG COVER 11 - PLUG SLEEVE 12 - THROTTLE PRESSURE SPRING AND PLUG
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21 - 475
DR VALVE BODY (Continued) VALVE BODY LOWER HOUSING (1) Remove timing valve cover. (2) Remove 3-4 timing valve and spring. (3) Remove 3-4 quick fill valve, spring and plug. (4) Remove 3-4 shift valve and spring. (5) Remove converter clutch valve, spring and plug
(6) Remove converter clutch timing valve, retainer
(Fig. 305).
and valve spring.
Fig.305LowerHousingShiftValvesandSprings
1 - 3-4 ACCUMULATOR HOUSING 2 - 3-4 SHIFT VALVE AND SPRING 3 - PLUG 4 - SPRING RETAINER 5 - CONVERTER CLUTCH VALVE AND SPRING 6 - CONVERTER CLUTCH TIMING VALVE AND SPRING 7 - OVERDRIVE SEPARATOR PLATE 8 - CASE CONNECTOR 9 - CONVERTER CLUTCH SOLENOID 10 - OVERDRIVE SOLENOID
11 - TIMING VALVE COVER 12 - PLUG 13 - 3-4 TIMING VALVE AND SPRING 14 - LOWER HOUSING 15 - ACCUMULATOR END PLATE 16 - 3-4 ACCUMULATOR PISTON AND SPRING 17 - E-CLIP 18 - 3-4 QUICK FILL SPRING AND VALVE 19 - SOLENOID GASKET 20 - HARNESS
AUTOMATIC TRANSMISSION - 48RE
21 - 476
VALVE BODY (Continued) 3-4 ACCUMULATOR HOUSING(1) Remove end plate from housing. (2) Remove piston spring. (3) Remove piston. Remove and discard piston
seals (Fig. 306).
DR
part has deformed, broken, etc.).
sustained
physical
damage
(dented,
CAUTION: Do not turn the small screw at the end of the solenoid valve for any reason. Turning the screw in either direction will ruin solenoid calibra- tion and result in solenoid failure. In addition, the filter on the solenoid valve is NOT serviceable. Do not try to remove the filter as this will damage the valve housing.
INSPECTION
Inspect the throttle and manual valve levers and shafts. Do not attempt to straighten a bent shaft or correct a loose lever. Replace these components if worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for scratches, nicks, burrs, or distortion. Use a straight- edge to check surface flatness. Minor scratches may be removed with crocus cloth using only very light pressure.
Minor distortion of a valve body mating surface may be corrected by smoothing the surface with a sheet of crocus cloth. Position the crocus cloth on a surface plate, sheet of plate glass or equally flat sur- face. If distortion is severe or any surfaces are heavily scored, the valve body will have to be replaced.
CAUTION: Many of the valves and plugs, such as the throttle valve, shuttle valve plug, 1-2 shift valve and 1-2 governor plug, are made of coated alumi- num. Aluminum components are identified by the dark color of the special coating applied to the sur- face (or by testing with a magnet). Do not sand alu- minum valves or plugs under any circumstances. This practice could damage the special coating causing the valves/plugs to stick and bind.
Inspect the valves and plugs for scratches, burrs, nicks, or scores. Minor surface scratches on steel valves and plugs can be removed with crocus cloth but do not round off the edges of the valve or plug lands.Maintaining sharpness of these edges is vitally important. The edges prevent foreign matter from lodging between the valves and plugs and the bore.
Inspect all the valve and plug bores in the valve body. Use a penlight to view the bore interiors. Replace the valve body if any bores are distorted or scored. Inspect all of the valve body springs. The springs must be free of distortion, warpage or broken coils.
Fig.3063-4AccumulatorandHousing
1 - ACCUMULATOR PISTON 2 - 3-4 ACCUMULATOR HOUSING 3 - TEFLON SEALS 4 - PISTON SPRING 5 - COVER PLATE AND SCREWS
CLEANING
Clean the valve housings, valves, plugs, springs, and separator plates with a standard parts cleaning solution only. Do not use gasoline, kerosene, or any type of caustic solution.
Do not immerse any of the electrical components in cleaning solution. Clean the governor solenoid and sensor and the dual solenoid and harness assembly by wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed air. Make sure all passages are clean and free from obstructions. Do not use rags or shop towels to dry or wipe off valve body components. Lint from these materials can stick to valve body parts, interfere with valve operation, and clog filters and fluid passages.
Wipe the governor pressure sensor and solenoid valve with dry, lint free shop towels only. The O-rings on the sensor and solenoid valve are the only service- able components. Be sure the vent ports in the sole- noid valve are open and not blocked by dirt or debris. Replace the valve and/or sensor only when DRB scan tool diagnosis indicates this is necessary. Or, if either
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21 - 477
ASSEMBLY
CAUTION: Do not force valves or plugs into place during reassembly. If the valve body bores, valves and plugs are free of distortion or burrs, the valve body components should all slide into place easily. In addition, do not overtighten the transfer plate and valve body screws during reassembly. Over- tightening can distort the housings resulting in valve sticking, cross leakage and unsatisfactory operation. Tighten valve body screws to recom- mended torque only.
LOWER HOUSING
(1) Lubricate valves, springs, and the housing valve and plug bores with clean transmission fluid (Fig. 307).
(2) Install 3-4 timing valve spring and valve in
lower housing.
housing.
(3) Install 3-4 quick fill valve in lower housing. (4) Install 3-4 quick fill valve spring and plug in
(5) Install timing valve end plate. Tighten end
plate screws to 4 N·m (35 in. lbs.) torque.
DR VALVE BODY (Continued)
Check the two separator plates for distortion or damage of any kind. Inspect the upper housing, lower housing, 3-4 accumulator housing, and transfer plate carefully. Be sure all fluid passages are clean and clear. Check condition of the upper housing and transfer plate check balls as well. The check balls and ball seats must not be worn or damaged.
Trial fit each valve and plug in its bore to check freedom of operation. When clean and dry, the valves and plugs should drop freely into the bores.
Valve body bores do not change dimensionally with use. If the valve body functioned correctly when new, it will continue to operate properly after cleaning and inspection. It should not be necessary to replace a valve body assembly unless it is damaged in han- dling.
The only serviceable valve body components are listed below. The remaining valve body components are serviced only as part of a complete valve body assembly. Serviceable parts are:
† dual solenoid and harness assembly † solenoid gasket † solenoid case connector O-rings and shoulder bolt† switch valve and spring † pressure adjusting screw and bracket assembly † throttle lever † manual lever and shaft seal † throttle lever shaft seal, washer, and E-clip † fluid filter and screws † detent ball and spring † valve body screws † governor pressure solenoid † governor pressure sensor and retaining clip † park lock rod and E-clip
21 - 478
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
DR
Fig.307LowerHousingShiftValvesandSprings
1 - 3-4 ACCUMULATOR HOUSING 2 - 3-4 SHIFT VALVE AND SPRING 3 - PLUG 4 - SPRING RETAINER 5 - CONVERTER CLUTCH VALVE AND SPRING 6 - CONVERTER CLUTCH TIMING VALVE AND SPRING 7 - OVERDRIVE SEPARATOR PLATE 8 - CASE CONNECTOR 9 - CONVERTER CLUTCH SOLENOID 10 - OVERDRIVE SOLENOID
11 - TIMING VALVE COVER 12 - PLUG 13 - 3-4 TIMING VALVE AND SPRING 14 - LOWER HOUSING 15 - ACCUMULATOR END PLATE 16 - 3-4 ACCUMULATOR PISTON AND SPRING 17 - E-CLIP 18 - 3-4 QUICK FILL SPRING AND VALVE 19 - SOLENOID GASKET 20 - HARNESS
AUTOMATIC TRANSMISSION - 48RE
21 - 479
DR VALVE BODY (Continued) 3-4 ACCUMULATOR
(1) Lubricate accumulator piston, seals and hous- ing piston bore with clean transmission fluid (Fig. 308).
(2) Install new seal rings on accumulator piston. (3) Install piston and spring in housing. (4) Install end plate on housing.
Fig.309RearClutchAndRearServoCheckBall
Locations
1 - REAR CLUTCH CHECK BALL 2 - REAR SERVO CHECK BALL 3 - TRANSFER PLATE
Fig.3083-4AccumulatorandHousing
1 - ACCUMULATOR PISTON 2 - 3-4 ACCUMULATOR HOUSING 3 - TEFLON SEALS 4 - PISTON SPRING 5 - COVER PLATE AND SCREWS
TRANSFER PLATE
Fig.310SeparatorPlateFilterScreenInstallation 1 - UPPER HOUSING SEPARATOR PLATE 2 - FILTER SCREEN
(1) Install rear clutch and rear servo check balls in
transfer plate (Fig. 309).
(2) Install filter screen in upper housing separator
plate (Fig. 310).
(3) Align and position upper housing separator
plate on transfer plate (Fig. 311).
(4) Install brace plate (Fig. 311). Tighten brace
attaching screws to 4 N·m (35 in. lbs.) torque.
(5) Install remaining separator plate attaching screws. Tighten screws to 4 N·m (35 in. lbs.) torque.
Fig.311BracePlate
1 - BRACE 2 - TRANSFER PLATE 3 - SEPARATOR PLATE
AUTOMATIC TRANSMISSION - 48RE
21 - 480
VALVE BODY (Continued) UPPER AND LOWER HOUSING(1) Position upper housing so internal passages and check ball seats are facing upward. Then install check balls in housing (Fig. 312). Seven check balls are used. The single large check ball is approxi- mately 8.7 mm (11/32 in.) diameter. The single small check ball in diameter. The remaining 5 check balls are approxi- mately 6.3 mm (1/4 in.) in diameter.
is approximately 4.8 mm (3/16 in.)
(2) Position assembled transfer plate and upper housing separator plate on upper housing (Fig. 313). Be sure filter screen is seated in proper housing recess.
DR
(3) Install the Number 10 check ball
into the transfer plate (Fig. 314). The check ball is approxi- mately 4.8 mm (3/16 in.) in diameter.
(4) Position lower housing separator plate on
transfer plate (Fig. 315).
(5) Install
lower housing on assembled transfer
plate and upper housing (Fig. 316).
(6) Install and start all valve body screws by hand except for the screws to hold the boost valve tube brace. Save those screws for later installation. Then tighten screws evenly to 4 N·m (35 in. lbs.) torque. Start at center and work out to sides when tighten- ing screws (Fig. 316).
Fig.312CheckBallLocationsInUpperHousing
1 - SMALL DIAMETER CHECK BALLS (5) 2 - LARGE DIAMETER CHECK BALL (1)
Fig.314Number10CheckBall
1 - NUMBER 10 CHECK BALL (3/169)
Fig.313InstallingTransferPlateOnUpperHousing 1 - FILTER SCREEN 2 - TRANSFER PLATE/SEPARATOR PLATE ASSEMBLY 3 - UPPER HOUSING
Fig.315LowerHousingSeparatorPlate
1 - BE SURE TO ALIGN BORES 2 - TRANSFER PLATE 3 - LOWER HOUSING (OVERDRIVE) SEPARATOR PLATE
DR VALVE BODY (Continued)
AUTOMATIC TRANSMISSION - 48RE
21 - 481
UPPER HOUSING VALVE AND PLUG
Refer to (Fig. 317), (Fig. 318) and (Fig. 319) to per-
form the following steps.
(1) Lubricate valves, plugs, springs with clean
transmission fluid.
(2) Assemble regulator valve line pressure sleeve, throttle plug and spring. Insert assembly in upper housing and install cover plate. Tighten cover plate screws to 4 N·m (35 in. lbs.) torque.
(3) Install 1-2 and 2-3 shift valves and springs. (4) Install 1-2 shift control valve and spring. (5) Install retainer, spring,
limit valve, and 2-3
throttle plug from limit valve housing.
(6) Install
limit valve housing and cover plate.
Tighten screws to 4 N·m (35 in. lbs.). (7) Install shuttle valve as follows:
(a) Insert plastic guides in shuttle valve second-
ary spring and install spring on end of valve.
(b) Install shuttle valve into housing. (c) Hold shuttle valve in place.
Fig.316InstallingLowerHousingOnTransferPlate
AndUpperHousing
1 - VALVE BODY SCREWS (13) 2 - LOWER HOUSING 3 - UPPER HOUSING 4 - TRANSFER PLATE
Fig.317ShuttleandBoostValveLocations
1 - SPRING 2 - RETAINER 3 - BOOST VALVE 4 - BOOST VALVE PLUG 5 - SPRING GUIDES 6 - E-CLIP 7 - SHUTTLE VALVE SECONDARY SPRING
8 - SHUTTLE VALVE COVER 9 - SHUTTLE VALVE 10 - SHUTTLE VALVE PRIMARY SPRING 11 - GOVERNOR PLUG COVER 12 - THROTTLE PLUG 13 - UPPER HOUSING 14 - BOOST VALVE COVER
21 - 482
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
DR
(d) Compress secondary spring and install E-clip
BOOST VALVE TUBE AND BRACE
in groove at end of shuttle valve.
(e) Verify that spring and E-clip are properly
seated before proceeding. (8) Install shuttle valve cover plate. Tighten cover
plate screws to 4 N·m (35 in. lbs.) torque.
(9) Install 1-2 and 2-3 valve governor plugs in
valve body.
(10) Install throttle plug.
shuttle valve primary spring and
(11) Align and install governor plug cover. Tighten
cover screws to 4 N·m (35 in. lbs.) torque.
(1) Position valve body assembly so lower housing
is facing upward (Fig. 320).
(2) Lubricate tube ends and housing ports with
transmission fluid or petroleum jelly.
(3) Start tube in lower housing port first. Then swing tube downward and work opposite end of tube into upper housing port (Fig. 320).
(4) Insert and seat each end of tube in housings. (5) Slide tube brace under tube and into alignment
with valve body screw holes (Fig. 321).
(6) Install and finger tighten three screws that secure tube brace to valve body housings (Fig. 321).
1 - UPPER HOUSING 2 - REGULATOR VALVE 3 - SWITCH VALVE 4 - REGULATOR VALVE SPRING 5 - KICKDOWN VALVE 6 - KICKDOWN DETENT 7 - THROTTLE VALVE AND SPRING
Fig.318UpperHousingControlValveLocations
8 - MANUAL VALVE 9 - 1-2 GOVERNOR PLUG 10 - GOVERNOR PLUG COVER 11 - THROTTLE PLUG 12 - 2-3 GOVERNOR PLUG 13 - SHUTTLE VALVE PRIMARY SPRING
DR VALVE BODY (Continued)
AUTOMATIC TRANSMISSION - 48RE
21 - 483
Fig.319UpperHousingShiftValveandPressurePlugLocations
1 - UPPER HOUSING 2 - 1-2 SHIFT VALVE AND SPRING 3 - 2-3 SHIFT VALVE AND SPRING 4 - 2-3 THROTTLE PLUG 5 - LIMIT VALVE HOUSING 6 - LIMIT VALVE COVER
7 - LIMIT VALVE AND SPRING 8 - RETAINER 9 - 1-2 SHIFT CONTROL VALVE AND SPRING 10 - PRESSURE PLUG COVER 11 - PLUG SLEEVE 12 - THROTTLE PRESSURE SPRING AND PLUG
Fig.320BoostValveTube
1 - BOOST VALVE TUBE 2 - LOWER HOUSING 3 - DISENGAGE THIS END OF TUBE FIRST 4 - UPPER HOUSING
Fig.321BoostValveTubeAndBrace
1 - BOOST VALVE TUBE 2 - TUBE BRACE
21 - 484
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
DR
(7) Bend tube brace tabs up and against tube to
hold it in position (Fig. 322).
(8) Tighten all valve body housing screws to 4 N·m (35 in. lbs.) torque after tube and brace are installed. Tighten screws in diagonal pattern starting at center and working outward.
Fig.322SecuringBoostValveTubeWithBrace
Tabs
1 - BEND TABS UP AGAINST TUBE AS SHOWN
3-4 ACCUMULATOR
Fig.323ConverterClutchAnd3-4ShiftValve
Springs
1 - RIGHT-SIDE SCREW 2 - 3-4 ACCUMULATOR 3 - 3-4 SHIFT VALVE SPRING 4 - CONVERTER CLUTCH VALVE SPRING
(1) Position converter clutch valve and 3-4 shift
valve springs in housing (Fig. 323).
(2) Loosely attach accumulator housing with right- side screw (Fig. 323). Install only one screw at this time as accumulator must be free to pivot upward for ease of installation.
(3) Install 3-4 shift valve and spring. (4) Install
converter
clutch timing valve and
spring.
(5) Position plug on end of converter clutch valve spring. Then compress and hold springs and plug in place with fingers of one hand.
(6) Swing accumulator housing upward over valve
springs and plug.
(7) Hold accumulator housing firmly in place and install remaining two attaching screws. Be sure springs and clutch valve plug are properly seated (Fig. 324). Tighten screws to 4 N·m (35 in. lbs.).
Fig.324Seating3-4AccumulatorOnLower
Housing
1 - ACCUMULATOR BOX 2 - CONVERTER CLUTCH VALVE PLUG
DR VALVE BODY (Continued) VALVE BODY FINAL
(1) Install boost valve, valve spring, retainer and cover plate. Tighten cover plate screws to 4 N·m (35
in. lbs.) torque.(2) Insert manual
lever detent spring in upper
housing.
(3) Position detent ball on end of spring. Then hold detent ball and spring in detent housing with Retainer Tool 6583 (Fig. 325).
(4) Install throttle lever in upper housing. Then lever over throttle lever and start
install manual manual lever into housing.
(5) Align manual lever with detent ball and man- ual valve. Hold throttle lever upward. Then press down on manual lever until fully seated. Remove detent ball retainer tool after lever is seated.
(6) Then install manual
lever seal, washer and
E-clip.
valve.
(7) Verify that throttle lever is aligned with end of kickdown valve stem and that manual lever arm is engaged in manual valve (Fig. 326).
(8) Position line pressure adjusting screw in
adjusting screw bracket.
(9) Install spring on end of line pressure regulator
(10) Install switch valve spring on tang at end of
adjusting screw bracket.
(11) Install manual valve. (12) Install throttle valve and spring. (13) Install kickdown valve and detent. (14) Install pressure regulator valve. (15) Install switch valve. (16) Position adjusting screw bracket on valve body. Align valve springs and press bracket into place. Install short, upper bracket screws first and long bottom screw last. Verify that valve springs and bracket are properly aligned. Then tighten all three bracket screws to 4 N·m (35 in. lbs.) torque.
AUTOMATIC TRANSMISSION - 48RE
21 - 485
(17) Perform Line Pressure and Throttle Pressure adjustments. (Refer to 21 - TRANSMISSION/TRANS- AXLE/AUTOMATIC/VALVE BODY - ADJUSTMENTS) (18) Lubricate solenoid case connector O-rings and shaft of manual lever with light coat of petroleum jelly. (19) Attach solenoid case connector to 3-4 accumu- lator with shoulder-type screw. Connector has small locating tang that fits in dimple at top of accumula- tor housing (Fig. 327). Seat tang in dimple before tightening connector screw.
Fig.326ManualAndThrottleLeverAlignment
1 - THROTTLE LEVER 2 - MANUAL LEVER VALVE ARM 3 - MANUAL VALVE 4 - KICKDOWN VALVE
Fig.325DetentBallSpring
1 - SPECIAL TOOL 6583 POSITIONED ON DETENT HOUSING
Fig.327SolenoidHarnessCaseConnector
ShoulderBolt
1 - SOLENOID HARNESS CASE CONNECTOR 2 - 3-4 ACCUMULATOR HOUSING
DR
(3) Check condition of seals on accumulator piston.
Install new piston seals, if necessary.
(4) Verify that transmission range sensor is NOT installed. Valve body cannot be installed with sensor in place.
(5) Place valve body manual lever in low (1 posi- tion) so ball on park lock rod will be easier to install in sprag.
(6) Lubricate shaft of manual lever with petroleum jelly. This will ease inserting shaft through seal in case.
(7) Lubricate seal rings on valve body harness con-
nector with petroleum jelly.
(8) Position valve body in case and work end of park lock rod into and through pawl sprag. Turn pro- peller shaft to align sprag and park lock teeth if nec- essary. The rod will click as it enters pawl. Move rod to check engagement.
CAUTION: It is possible for the park rod to displace into a cavity just above the pawl sprag during installation. Make sure the rod is actually engaged in the pawl and has not displaced into this cavity.
(9) Install accumulator spring and piston into case. Then swing valve body over piston and outer spring to hold it in place.
(10) Align accumulator piston and outer spring, manual lever shaft and electrical connector in case. (11) Then seat valve body in case and install one
or two bolts to hold valve body in place.
(12) Tighten valve body bolts alternately and
evenly to 11 N·m (100 in. lbs.) torque.
(13) Install new fluid filter on valve body. Tighten
filter screws to 4 N·m (35 in. lbs.) torque.
(14) Install throttle and gearshift levers on valve
body manual lever shaft.
21 - 486
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 48RE
(20) Install solenoid assembly and gasket. Tighten solenoid attaching screws to 8 N·m (72 in. lbs.) torque. (21) Verify that solenoid wire harness is properly routed (Fig. 328). Solenoid harness must be clear of manual lever and park rod and not be pinched between accumulator housing and cover.
Fig.328SolenoidHarnessRouting
1 - OVERDRIVE/CONVERTER SOLENOID WIRE HARNESS 2 - 3-4 ACCUMULATOR COVER PLATE
GOVERNOR BODY, SENSOR AND SOLENOID
(1) Turn valve body assembly over so accumulator
side of transfer plate is facing down.
(2) Install new O-rings on governor pressure sole-
noid and sensor.
(3) Lubricate solenoid and sensor O-rings with
clean transmission fluid.
(4) Install governor pressure sensor in governor body. (5) Install governor pressure solenoid in governor body. Push solenoid in until it snaps into place in body. (6) Position governor body gasket on transfer plate. (7) Install retainer plate on governor body and around solenoid. Be sure solenoid connector is posi- tioned in retainer cutout.
(8) Align screw holes in governor body and trans- fer plate. Then install and tighten governor body screws to 4 N·m (35 in. lbs.) torque.
(9) Connect harness wires to governor pressure
solenoid and governor pressure sensor.
(10) Install fluid filter and pan. (11) Lower vehicle. (12) Fill transmission with recommended fluid and
road test vehicle to verify repair.
INSTALLATION
(1) Check condition of O-ring seals on valve body harness connector (Fig. 329). Replace seals on con- nector body if cut or worn.
(2) Check condition of manual
in transmission case. Replace seal if lip is cut or worn. Install new seal with 15/16 deep well socket (Fig. 330).
lever shaft seal
Fig.329ValveBodyHarnessConnectorO-RingSeal 1 - CONNECTOR O-RINGS 2 - VALVE BODY HARNESS CONNECTOR 3 - HARNESS
AUTOMATIC TRANSMISSION - 48RE
21 - 487
Turning the adjusting screw counterclockwise increases pressure while turning the screw clockwise decreases pressure.
Fig.331LinePressureAdjustment
1 - WRENCH 2 - 1–5/16 INCH
THROTTLE PRESSURE ADJUSTMENT
Insert Gauge Tool C-3763 between the throttle
lever cam and the kickdown valve stem (Fig. 332).
Push the gauge tool inward to compress the kick- down valve against the spring and bottom the throt- tle valve.
Maintain pressure against kickdown valve spring. Turn throttle lever stop screw until the screw head touches throttle lever tang and the throttle lever cam touches gauge tool.
NOTE: The kickdown valve spring must be fully compressed and the kickdown valve completely bottomed to obtain correct adjustment.
DR VALVE BODY (Continued)
(15) Check and adjust front and rear bands if nec-
essary.
(16) Connect solenoid case connector wires. (17) Install the transmission range sensor. (18) Install oil pan and new gasket. Tighten pan
bolts to 17 N·m (13 ft. lbs.) torque.
(19) Lower vehicle and fill
transmission with
Mopart ATF +4, Automatic Transmission fluid.
(20) Check and adjust gearshift and throttle valve
cables, if necessary.
Fig.330ManualLeverShaftSeal
1 - 15/1688 SOCKET 2 - SEAL
ADJUSTMENTS - VALVE BODY
CONTROL PRESSURE ADJUSTMENTS
valve body;
There are two control pressure adjustments on the † Line Pressure † Throttle Pressure Line and throttle pressures are interdependent because each affects shift quality and timing. As a result, both adjustments must be performed properly and in the correct sequence. Adjust line pressure first and throttle pressure last.
LINE PRESSURE ADJUSTMENT
Measure distance from the valve body to the inner edge of the adjusting screw with an accurate steel scale (Fig. 331).
Distance should be 33.4 mm (1-5/16 in.). If adjustment is required, turn the adjusting screw
in, or out, to obtain required distance setting.
NOTE: The 33.4 mm (1-5/16 in.) setting is an approximate setting. Manufacturing tolerances may make it necessary to vary from this dimension to obtain desired pressure.
One complete turn of the adjusting screw changes
line pressure approximately 1-2/3 psi (9 kPa).
Fig.332ThrottlePressureAdjustment
1 - HEX WRENCH (IN THROTTLE LEVER ADJUSTING SCREW) 2 - SPECIAL TOOL C-3763 (POSITIONED BETWEEN THROTTLE LEVER AND KICKDOWN VALVE)
21 - 488
AUTOMATIC TRANSMISSION - 45RFE/545RFE
AUTOMATIC TRANSMISSION - 45RFE/545RFE
TABLE OF CONTENTS
page
DR
page
AUTOMATIC TRANSMISSION - 45RFE/545RFE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 489
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 490
DIAGNOSIS AND TESTINGDIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . 491
DIAGNOSIS AND TESTING - PRELIMINARY . . 491
DIAGNOSIS AND TESTING - ROADTESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . 491
DIAGNOSIS AND TESTING - HYDRAULIC
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION . . . . . . . . . . . . . . . . . . . . 541
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542
STANDARD PROCEDURE - FLUID AND
FILTER REPLACEMENT . . . . . . . . . . . . . . . 542
STANDARD PROCEDURE - TRANSMISSION
FILL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544
GEARSHIFT CABLE
PRESSURE TEST . . . . . . . . . . . . . . . . . . . . 493
DIAGNOSIS AND TESTING - GEARSHIFT
DIAGNOSIS AND TESTING - AIR CHECKING
TRANSMISSION CLUTCH OPERATION . . . . 494
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK . . . . . . . . . . . . . . . . 495
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR . . . . . . . . . . . . . . . . . . . . . 495
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 497
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 503
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 503
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 510
SCHEMATICS AND DIAGRAMSHYDRAULIC SCHEMATICS . . . . . . . . . . . . . 513
SPECIFICATIONS TRANSMISSION
SPECIAL TOOLS
. . . . . . . . . . . . . . . . . . . . . 534
RFE TRANSMISSION
. . . . . . . . . . . . . . . . . 535
4C RETAINER/BULKHEAD
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 538
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 538ADAPTER HOUSING SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 539BRAKE TRANSMISSION SHIFT INTERLOCK
SYSTEM DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 540
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 540
DIAGNOSIS AND TESTING - BRAKETRANSMISSION SHIFT INTERLOCK . . . . . . 540
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK
. . . . . . . . . . . . . . . . . . . 540
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL . . . . . . . . . . . . . 541
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID . . . . . . . . . . . . . . . . . . . . . . . 541
CABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 545
ADJUSTMENTSGEARSHIFT CABLE
. . . . . . . . . . . . . . . . . . 546
HOLDING CLUTCHES
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 546
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 546INPUT CLUTCH ASSEMBLY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 549
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 549
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 550
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 552INPUT SPEED SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 558
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 558
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 559LINE PRESSURE (LP) SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 559
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 559
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 560LOW/REVERSE CLUTCH
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 560
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 561
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 561
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 561OIL PUMP
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 562
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 562
STANDARD PROCEDURE - OIL PUMPVOLUME CHECK . . . . . . . . . . . . . . . . . . . . . 563
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 564
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 566
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 566
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 566DR
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 489
OIL PUMP FRONT SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 567OUTPUT SPEED SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 567
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 567
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 567OVERDRIVE SWITCH
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 568
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 568
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 569PISTONS
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 569
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 569PLANETARY GEARTRAIN
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 571
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 571
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 573
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 573
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 573SHIFT MECHANISM
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 574
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 574SOLENOID SWITCH VALVE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 574
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 574SOLENOIDS
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 574
AUTOMATIC TRANSMISSION - 45RFE/545RFE DESCRIPTION
The 45RFE/545RFE automatic transmissions is a sophisticated, multi-range, electronically controlled transmission which combines optimized gear ratios for responsive performance, state of the art efficiency features and low NVH. Other features include driver adaptive shifting and three planetary gear sets to provide wide ratio capability with precise ratio steps for optimum driveability. The three planetary gear sets also make available a unique alternate second gear ratio. The primary 2nd gear ratio fits between 1st and 3rd gears for normal through-gear accelera- tions. The alternate second gear ratio (2prime) allows smoother 4-2 kickdowns at high speeds to provide 2nd gear passing performance over a wider highway cruising range.
The hydraulic portion of the transmission consists of the transmission fluid, fluid passages, hydraulic valves, and various line pressure control components.
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 575
TORQUE CONVERTER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 575
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 579
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 580TRANSMISSION CONTROL RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 581
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 581TRANSMISSION RANGE SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 581
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 581TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 582
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 582
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 583TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 583
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 583VALVE BODY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 584
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 585
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 586
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 588
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 588
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 590
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 590mission consist of the following:
The primary mechanical components of the trans- † Three multiple disc input clutches † Three multiple disc holding clutches † Five hydraulic accumulators † Three planetary gear sets † Dual Stage Hydraulic oil pump † Valve body † Solenoid pack The TCM is the “heart” or “brain” of the electronic control system and relies on information from vari- ous direct and indirect inputs (sensors, switches, etc.) to determine driver demand and vehicle operating conditions. With this information, the TCM can cal- culate and perform timely and quality shifts through various output or control devices (solenoid pack, transmission control relay, etc.).
TRANSMISSION IDENTIFICATION
Transmission identification numbers are stamped on the left side of the case just above the oil pan sealing surface (Fig. 1). Refer to this information when ordering replacement parts. A label is attached to the transmission case above the stamped numbers.
21 - 490
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
The label gives additional also be necessary for identification purposes.
information which may
Fig.1TransmissionPartAndSerialNumber
Location
1 - IDENTIFICATION NUMBERS (STAMPED)
GEAR RATIOS
The 45RFE gear ratios are:
1st . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1
2nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.67:1
2nd Prime . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.50:1
3rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.00:1
4th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.75:1
Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1
GEAR RATIOSThe 545RFE gear ratios are:
1st . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1
2nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.67:1
2nd Prime . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.50:1
3rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.00:1
4th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.75:1
5th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.67:1
Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1OPERATION
The 45RFE/545RFE offers full electronic control of all automatic up and downshifts, and features real- time adaptive closed-loop shift and pressure control. Electronic shift and torque converter clutch controls help protect the transmission from damage due to high temperatures, which can occur under severe operating conditions. By altering shift schedules, line pressure, and converter clutch control, these controls reduce heat generation and increase transmission cooling.
To help reduce efficiency-robbing parasitic losses, the transmissions includes a dual-stage transmission fluid pump with electronic output pressure control. Under most driving conditions, pump output pres- sure greatly exceeds that which is needed to keep the clutches applied. The 45RFE/545RFE pump-pressure control system monitors input torque and adjusts the pump pressure accordingly. The primary stage of the pump works the second stage is bypassed when demand is low. The control system also monitors input and output speed and, if incipi- ent clutch slip is observed, the pressure control sole- noid duty cycle is varied, increasing pressure in proportion to demand.
continuously;
A high-travel torque converter damper assembly allows earlier torque converter clutch engagement to reduce slippage. Needle-type thrust bearings reduce internal friction. The 45RFE/545RFE is packaged in a one-piece die-cast aluminum case. To reduce NVH, the case has high lateral, vertical and torsional stiff- ness. It is also designed to maximize the benefit of the structural dust cover that connects the bottom of the bell housing to the engine bedplate, enhancing overall power train stiffness. Dual filters protect the pump and other components. A pump return filter is added to the customary main sump filter. Indepen- dent lubrication and cooler circuits assure ample pressure for normal transmission operation even if the cooler is obstructed or the fluid cannot flow due to extremely low temperatures.
The hydraulic control system design (without elec- tronic assist) provides the transmission with PARK, REVERSE, NEUTRAL, SECOND, and THIRD gears, based solely on driver shift lever selection. This design allows the vehicle to be driven (in “limp-in” mode) in the event of a electronic control system fail- ure, or a situation that the Transmission Control Module (TCM) recognizes as potentially damaging to the transmission.
The TCM also performs certain self-diagnostic functions and provides comprehensive information (sensor data, DTC’s, etc.) which is helpful in proper diagnosis and repair. This information can be viewed with the DRBt scan tool.
DR AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued) DIAGNOSIS AND TESTING
VEHICLE IS DISABLED
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 491
DIAGNOSIS AND TESTING - AUTOMATIC TRANSMISSION
CAUTION: Before attempting any repair on a RFE automatic transmission, check for Diagnostic Trou- ble Codes with the DRBT scan tool.
Transmission malfunctions may be caused by these general conditions: † Poor engine performance † Improper adjustments † Hydraulic malfunctions † Mechanical malfunctions † Electronic malfunctions Diagnosis of these problems should always begin by checking the easily accessible variables: fluid level and condition, gearshift cable adjustment. Then per- form a road test to determine if the problem has been corrected or if more diagnosis is necessary. If the problem persists after the preliminary tests and cor- rections are completed, hydraulic pressure checks should be performed.
DIAGNOSIS AND TESTING - PRELIMINARY
Two basic procedures are required. One procedure for vehicles that are drivable and an alternate proce- dure for disabled vehicles (will not back up or move forward).
VEHICLE IS DRIVABLE
(1) Check for transmission fault codes using DRBt
scan tool.
(2) Check fluid level and condition. (3) Adjust gearshift cable if complaint was based
on delayed, erratic, or harsh shifts.
(4) Road test and note how transmission upshifts,
downshifts, and engages.
(5) Perform hydraulic pressure test if shift prob-
lems were noted during road test.
(6) Perform air-pressure test to check clutch oper-
ation.
(1) Check fluid level and condition. (2) Check for broken or disconnected gearshift
cable.
(3) Check for cracked, leaking cooler lines, or loose
or missing pressure-port plugs.
(4) Raise and support vehicle on safety stands, start engine, shift transmission into gear, and note following:
(a) If propeller shaft turns but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shaft does not turn and transmis- sion is noisy, stop engine. Remove oil pan, and check for debris. If pan is clear, remove transmis- sion and check for damaged driveplate, converter, oil pump, or input shaft.
(c) If propeller shaft does not turn and transmis- sion is not noisy, perform hydraulic-pressure test to determine if problem is hydraulic or mechanical.
DIAGNOSIS AND TESTING - ROAD TESTING
Before road testing, be sure the fluid level and con- trol cable adjustments have been checked and adjusted if necessary. Verify that all diagnostic trou- ble codes have been resolved.
Observe engine performance during the road test. A poorly tuned engine will not allow accurate analy- sis of transmission operation.
Operate the transmission in all gear ranges. Check for shift variations and engine flare which indicates slippage. Note if shifts are harsh, spongy, delayed, early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means clutch, overrunning clutch, or line pressure problems. A slipping clutch can often be determined by com- paring which internal units are applied in the vari- ous gear ranges. The Clutch Application charts provide a basis for analyzing road test results.
21 - 492
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
45RFE CLUTCH APPLICATION CHART
SLP
UD
OD
2C
4C
P–PARK
R–REVERSE N-NEUTRAL
D–OVERDRIVE
FIRST
SECOND
SECOND PRIME
THIRD FOURTH LIMP-IN 2–FIRST SECOND LIMP-IN 1–LOW
ON
ON ON ON
ON ON ON ON ON
ON
ON ON ON
ON
ON
ON
ON ON
L/R
ON ON ON
ON*
ON*
ON
*L/R clutch is on only with the output shaft speed below 150 rpm.
545RFE CLUTCH APPLICATION CHART
