Login- Download PDF Manual
-
rect torque is 12 N·m (105 in.lbs.).
OIL PUMP FRONT SEAL REMOVAL
(1) Remove transmission from the vehicle. (2) Remove the torque converter from the trans-
mission.
(3) Using a screw mounted in a slide hammer,
remove the oil pump front seal.
INSTALLATION
(1) Clean seal bore of the oil pump of any residue
or particles from the original seal.
(2) Install new oil seal in the oil pump housing
using Seal Installer C-3860-A (Fig. 104).
OUTPUT SPEED SENSOR DESCRIPTION
The Input and Output Speed Sensors are two-wire magnetic pickup devices that generate AC signals as rotation occurs. They are mounted in the left side of the transmission case and are considered primary inputs to the Transmission Control Module (TCM).
OPERATION
The Input Speed Sensor provides information on how fast the input shaft is rotating. As the teeth of the input clutch hub pass by the sensor coil, an AC voltage is generated and sent to the TCM. The TCM interprets this information as input shaft rpm.
The Output Speed Sensor generates an AC signal in a similar fashion, though its coil is excited by rota-
Fig.104InstallOilPumpFrontSeal
1 - TOOL C-3860-A
tion of the rear planetary carrier lugs. The TCM interprets this information as output shaft rpm.
signals to determine the following:
The TCM compares the input and output speed † Transmission gear ratio † Speed ratio error detection † CVI calculation The TCM also compares the input speed signal and † Torque converter clutch slippage † Torque converter element speed ratio
the engine speed signal to determine the following:
REMOVAL
(1) Raise vehicle. (2) Place a suitable fluid catch pan under the
transmission.
(3) Remove the wiring connector from the output
speed sensor (Fig. 105).
(4) Remove the bolt holding the output speed sen-
sor to the transmission case.
(5) Remove the output speed sensor from the
transmission case.
INSTALLATION
mission case.
(1) Install the output speed sensor into the trans-
(2) Install the bolt to hold the output speed sensor into the transmission case. Tighten the bolt to 11.9
N·m (105 in.lbs.).(3) Install the wiring connector onto the output
(4) Verify the transmission fluid level. Add fluid as
speed sensor
necessary.
(5) Lower vehicle.
21 - 568
OVERDRIVE SWITCH (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
trol switch is the ON position. The switch must be in this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates only when the overdrive switch is turned to the OFF position, or when illuminated by the transmission control module.REMOVAL
(1) Using a plastic trim tool, remove the overdrive
off switch retainer from the shift lever (Fig. 107).
Fig.105OutputSpeedSensor
1 - OUTPUT SPEED SENSOR 2 - LINE PRESSURE SENSOR 3 - INPUT SPEED SENSOR
OVERDRIVE SWITCH DESCRIPTION
The overdrive OFF (control) switch is located in the shift lever arm (Fig. 106). The switch is a momentary contact device that signals the PCM to toggle current status of the overdrive function.
Fig.107OverdriveOffSwitchRetainer
1 - GEAR SHIFT LEVER 2 - OVERDRIVE OFF SWITCH RETAINER 3 - PLASTIC TRIM TOOL
(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 108)
Fig.106OverdriveOffSwitch
OPERATION
At key-on, overdrive operation is allowed. Pressing the switch once causes the overdrive OFF mode to be entered and the overdrive OFF switch lamp to be illuminated. Pressing the switch a second time causes normal overdrive operation to be restored and the overdrive lamp to be turned off. The overdrive OFF mode defaults to ON after the ignition switch is cycled OFF and ON. The normal position for the con-
Fig.108RemovetheOverdriveOffSwitch
1 - GEAR SHIFT LEVER 2 - OVERDRIVE OFF SWITCH
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 569
DR OVERDRIVE SWITCH (Continued) INSTALLATION
NOTE: There is enough slack in the wire to pull out the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the overdrive off switch. Use care when installing the switch, as it is not indexed, and can be accidentally installed incorrectly.
(2) Install the overdrive off switch into the connec-
tor (Fig. 109)
Fig.109InstalltheOverdriveOffSwitch
1 - GEAR SHIFT LEVER 2 - OVERDRIVE OFF SWITCH WIRING CONNECTOR 3 - OVERDRIVE OFF SWITCH
(3) Push the overdrive off switch and wiring into
(4) Install the overdrive off switch retainer onto
the shift lever.
the shift lever.
PISTONS DESCRIPTION
There are several sizes and types of pistons used in an automatic transmission. Some pistons are used to apply clutches, while others are used to apply bands. They all have in common the fact that they are round or circular in shape, located within a smooth walled cylin- der, which is closed at one end and converts fluid pres- sure into mechanical movement. The fluid pressure exerted on the piston is contained within the system through the use of piston rings or seals.
OPERATION
The principal which makes this operation possible is known as Pascal’s Law. Pascal’s Law can be stated
as: “Pressure on a confined fluid is transmitted equally in all directions and acts with equal force on equal areas.”
PRESSURE
Pressure (Fig. 110) is nothing more than force (lbs.) divided by area (in or ft.), or force per unit area. Given a 100 lb. block and an area of 100 sq. in. on the floor, the pressure exerted by the block is: 100
lbs. 100 in or 1 pound per square inch, or PSI as it is commonly referred to.Fig.110ForceandPressureRelationship
PRESSURE ON A CONFINED FLUID
Pressure is exerted on a confined fluid (Fig. 111) by applying a force to some given area in contact with the fluid. A good example of this is a cylinder filled with fluid and equipped with a piston that is closely fitted to the cylinder wall. If a force is applied to the piston, pressure will be developed in the fluid. Of course, no pressure will be created if the fluid is not confined. It will simply “leak” past the piston. There must be a resistance to flow in order to create pres- sure. Piston sealing is extremely important in hydraulic operation. Several kinds of seals are used to accomplish this within a transmission. These include but are not limited to O-rings, D-rings, lip seals, sealing rings, or extremely close tolerances between the piston and the cylinder wall. The force exerted is downward (gravity), however, the principle remains the same no matter which direction is taken. The pressure created in the fluid is equal to the force applied, divided by the piston area. If the force is 100
lbs., and the piston area is 10 sq. in., then the pres- sure created equals 10 PSI. Another interpretation of21 - 570
PISTONS (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
Pascal’s Law is that regardless of container shape or size, the pressure will be maintained throughout, as long as the fluid is confined. In other words, the pressure in the fluid is the same everywhere within the container.
DR
Fig.111PressureonaConfinedFluid
FORCE MULTIPLICATION
Using the 10 PSI example used in the illustration (Fig. 112), a force of 1000 lbs. can be moved with a force of only 100 lbs. The secret of force multiplica- tion in hydraulic systems is the total fluid contact area employed. The illustration, (Fig. 112), shows an area that is ten times larger than the original area. The pressure created with the smaller 100 lb. input is 10 PSI. The concept “pressure is the same every- where” means that the pressure underneath the larger piston is also 10 PSI. Pressure is equal to the force applied divided by the contact area. Therefore, by means of simple algebra, the output force may be found. This concept is extremely important, as it is also used in the design and operation of all shift valves and limiting valves in the valve body, as well as the pistons, of the transmission, which activate the clutches and bands. It is nothing more than using a difference of area to create a difference in pressure to move an object.
PISTON TRAVEL
The relationship between hydraulic lever and a lever is the same. With a mechanical mechanical lever it’s a weight-to-distance output rather than a pressure-to-area output. Using the same forces and areas as in the previous example, the smaller piston
Fig.112ForceMultiplication
(Fig. 113) has to move ten times the distance required to move the larger piston one inch. There- fore, for every inch the larger piston moves, the smaller piston moves ten inches. This principle is true in other instances also. A common garage floor jack is a good example. To raise a car weighing 2000
lbs., an effort of only 100 lbs. may be required. For every inch the car moves upward, the input piston at the jack handle must move 20 inches downward.Fig.113PistonTravel
DR
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 571
PLANETARY GEARTRAIN DESCRIPTION
The planetary geartrain is located behind the 4C retainer/bulkhead, toward the rear of the transmis- sion. The planetary geartrain consists of three pri- mary assemblies: † Reaction (Fig. 114). † Reverse (Fig. 115). † Input (Fig. 115).
OPERATION
REACTION PLANETARY GEARTRAIN
The reaction planetary carrier and reverse sun gear of the reaction planetary geartrain are a single component which is held by the 2C clutch when required. The reaction annulus gear is a stand alone component that can be driven by the reverse clutch or held by the 4C clutch. The reaction sun gear is driven by the overdrive clutch.
Fig.114ReactionPlanetaryGeartrain
1 - BEARING NUMBER 8
2 - BEARING NUMBER 9
3 - REACTION PLANETARY CARRIER 4 - REACTION SUN GEAR5 - BEARING NUMBER 7
6 - THRUST PLATE (SELECT) 7 - BEARING NUMBER 6
8 - REACTION ANNULUS21 - 572
PLANETARY GEARTRAIN (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
1 - SNAP-RING 2 - BEARING NUMBER 10
3 - BEARING NUMBER 11
4 - INPUT ANNULUSFig.115Reverse/InputPlanetaryGeartrain
5 - INPUT PLANETARY CARRIER 6 - INPUT SUN GEAR 7 - REVERSE PLANETARY CARRIER
REVERSE PLANETARY GEARTRAIN
The reverse planetary geartrain is the middle of the three planetary sets. The reverse planetary car- rier can be driven by the overdrive clutch as required. The reverse planetary carrier is also splined to the input annulus gear, which can be held by the low/reverse clutch. The reverse planetary annulus, input planetary carrier, and output shaft are all one piece.
INPUT PLANETARY GEARTRAIN
The input
sun gear of
the input planetary
geartrain is driven by the underdrive clutch.
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 573
DR PLANETARY GEARTRAIN (Continued) DISASSEMBLY
(1) Remove the snap-ring holding the input annu-
lus into the input carrier (Fig. 116).
(2) Remove the input annulus from the input car-
rier (Fig. 116).
(3) Remove the number 9 bearing from the reverse planetary carrier. Note that this planetary carrier has four pinion gears.
(4) Remove the reverse planetary gear carrier (Fig.
116).
sun gear (Fig. 116).
rier (Fig. 116).
carrier (Fig. 116).
(5) Remove the number 10 bearing from the input
(6) Remove the input sun gear from the input car-
(7) Remove the number 11 bearing from the input
CLEANING
Clean the planetary components in solvent and dry
them with compressed air.
INSPECTION
Check sun gear and driving shell
condition. Replace the gear if damaged or if the bushings are
scored or worn. The bushings are not serviceable. Replace the driving shell if worn, cracked or dam- aged.
Replace planetary gear sets if gears, pinion pins, or carrier are damaged in any way. Replace the annulus gears and supports if either component is worn or damaged.
Replace the output shaft if the machined surfaces are scored, pitted, or damaged in any way. Also replace the shaft if the splines are damaged, or exhibits cracks at any location.
ASSEMBLY
(1) Clean and inspect all components. Replace any components which show evidence of excessive wear or scoring.
(2) Install the number 11 bearing into the input planetary carrier so that the inner race will be toward the front of the transmission (Fig. 116).
(3) Install the input sun gear into the input carrier
(Fig. 116).
(4) Install the number 10 bearing onto the rear of the reverse planetary carrier with the inner race toward the carrier (Fig. 116).
1 - SNAP-RING 2 - BEARING NUMBER 10
3 - BEARING NUMBER 11
4 - INPUT ANNULUSFig.116Reverse/InputPlanetaryCarrierAssembly
5 - INPUT PLANETARY CARRIER 6 - INPUT SUN GEAR 7 - REVERSE PLANETARY CARRIER
21 - 574
PLANETARY GEARTRAIN (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
(5) Install the number 9 bearing onto the front of the reverse planetary carrier with the outer race toward the carrier and the inner race facing upward (Fig. 116).
(6) Install the reverse planetary gear carrier into
the input carrier (Fig. 116).
(7) Install the input annulus gear into the input
carrier (Fig. 116).
(8) Install the snap-ring to hold the input annulus
gear into the input carrier (Fig. 116).
SHIFT MECHANISM DESCRIPTION
The gear shift mechanism provides six shift posi- tions which are: † Park (P) † Reverse (R) † Neutral (N) † Drive (D) † Manual second (2) † Manual low (1)
OPERATION
MANUAL LOW (1) range provides first gear only. Overrun braking is also provided in this range. MANUAL SECOND (2) range provides first and sec- ond gear only.
DRIVE range provides FIRST, SECOND, THIRD, OVERDRIVE FOURTH, and OVERDRIVE FIFTH (if applicable) gear ranges. The shift into OVERDRIVE FOURTH and FIFTH (if applicable) gear ranges occurs only after the transmission has completed the shift into D THIRD gear range. No further movement of the shift mechanism is required to complete the 3-4 or 4-5 (if applicable) shifts.
The FOURTH and FIFTH (if applicable) gear upshifts occur automatically when the overdrive selector switch is in the ON position. No upshift to FOURTH or FIFTH (if applicable) gears will occur if any of the following are true: † The transmission fluid temperature is below 10° † The shift to THIRD is not yet complete. † Vehicle speed is too low for the 3-4 or 4-5 (if
C (50° F) or above 121° C (250° F).
applicable) shifts to occur.
Upshifts into FOURTH or FIFTH (if applicable) will be delayed when the transmission fluid temper- ature is below 4.5° C (40° F) or above 115.5° C (240° F).
SOLENOID SWITCH VALVE DESCRIPTION
The Solenoid Switch Valve (SSV) is located in the valve body and controls the direction of the transmis- sion fluid when the L/R-TCC solenoid is energized.
OPERATION
The Solenoid Switch Valve controls line pressure from the LR-TCC solenoid. In 1st gear, the SSV will be in the downshifted position, thus directing fluid to the L/R clutch circuit. In 2nd, 3rd, 4th, and 5th (if applicable) gears, the solenoid switch valve will be in the upshifted position and directs the fluid into the torque converter clutch (TCC) circuit.
When shifting into 1st gear, a special hydraulic sequence is performed to ensure SSV movement into the downshifted position. The L/R pressure switch is monitored to confirm SSV movement. If the move- ment is not confirmed (the L/R pressure switch does not close), 2nd gear is substituted for 1st. A DTC will be set after three unsuccessful attempts are made to get into 1st gear in one given key start.
SOLENOIDS DESCRIPTION
The typical electrical solenoid used in automotive applications is a linear actuator. It is a device that produces motion in a straight line. This straight line motion can be either forward or backward in direc- tion, and short or long distance.
A solenoid is an electromechanical device that uses a magnetic force to perform work. It consists of a coil of wire, wrapped around a magnetic core made from steel or iron, and a spring loaded, movable plunger, which performs the work, or straight line motion.
The solenoids used in transmission applications are attached to valves which can be classified as nor- mally open or normally closed. The normally open solenoid valve is defined as a valve which allows hydraulic flow when no current or voltage is applied to the solenoid. The normally closed sole- noid valve is defined as a valve which does not allow hydraulic flow when no current or voltage is applied to the solenoid. These valves perform hydraulic con- trol functions for the transmission and must there- fore be durable and tolerant of dirt particles. For these reasons, the valves have hardened steel pop- pets and ball valves. The solenoids operate the valves directly, which means that the solenoids must have very high outputs to close the valves against the siz- able flow areas and line pressures found in current transmissions. Fast response time is also necessary to ensure accurate control of the transmission.
DR SOLENOIDS (Continued)
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 575
The strength of the magnetic field is the primary force that determines the speed of operation in a par- ticular solenoid design. A stronger magnetic field will cause the plunger to move at a greater speed than a weaker one. There are basically two ways to increase the force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil. The most common practice is to increase the num- ber of turns by using thin wire that can completely fill the available space within the solenoid housing. The strength of the spring and the length of the plunger also contribute to the response speed possi- ble by a particular solenoid design.
is controlled. Some of
A solenoid can also be described by the method by which it the possibilities include variable force, pulse-width modulated, con- stant ON, or duty cycle. The variable force and pulse- width modulated versions utilize similar methods to control the current flow through the solenoid to posi- tion the solenoid plunger at a desired position some- where between full ON and full OFF. The constant ON and duty cycled versions control the voltage across the solenoid to allow either full flow or no flow through the solenoid’s valve.
TORQUE CONVERTER DESCRIPTION
The torque converter (Fig. 117)
is a hydraulic device that couples the engine crankshaft to the transmission. The torque converter consists of an outer shell with an internal turbine, a stator, an overrunning clutch, an impeller and an electronically applied converter clutch. The converter clutch pro- vides reduced engine speed and greater fuel economy when engaged. Clutch engagement also provides reduced transmission fluid temperatures. The torque converter hub drives the transmission oil (fluid) pump and contains an o-ring seal to better control oil flow.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced if a transmission failure resulted in large amounts of metal or fiber contamination in the fluid.
OPERATION
When an electrical current is applied to the sole- noid coil, a magnetic field is created which produces an attraction to the plunger, causing the plunger to move and work against the spring pressure and the load applied by the fluid the valve is controlling. The plunger is normally directly attached to the valve which it is to operate. When the current is removed from the coil, the attraction is removed and the plunger will return to its original position due to spring pressure.
The plunger is made of a conductive material and accomplishes this movement by providing a path for the magnetic field to flow. By keeping the air gap between the plunger and the coil to the minimum necessary to allow free movement of the plunger, the magnetic field is maximized.
Fig.117TorqueConverterAssembly
1 - TURBINE ASSEMBLY 2 - STATOR 3 - CONVERTER HUB 4 - O-RING 5 - IMPELLER ASSEMBLY 6 - CONVERTER CLUTCH PISTON 7 - TURBINE HUB
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 576
TORQUE CONVERTER (Continued) IMPELLERThe impeller (Fig. 118) is an integral part of the converter housing. The impeller consists of curved blades placed radially along the inside of the housing on the transmission side of the converter. As the con- verter housing is rotated by the engine, so is the impeller, because they are one and the same and are the driving members of the system.
DR
1 - ENGINE FLEXPLATE 2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE SECTION 3 - IMPELLER VANES AND COVER ARE INTEGRAL
Fig.118Impeller
4 - ENGINE ROTATION 5 - ENGINE ROTATION
DR TORQUE CONVERTER (Continued) TURBINE
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 577
The turbine (Fig. 119) is the output, or driven, member of the converter. The turbine is mounted within the housing opposite the impeller, but is not attached to the housing. The input shaft is inserted through the center of the impeller and splined into the turbine. The design of the turbine is similar to the impeller, except the blades of the turbine are curved in the opposite direction.
1 - TURBINE VANE 2 - ENGINE ROTATION 3 - INPUT SHAFT
Fig.119Turbine
4 - PORTION OF TORQUE CONVERTER COVER 5 - ENGINE ROTATION 6 - OIL FLOW WITHIN TURBINE SECTION
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 578
TORQUE CONVERTER (Continued) STATORThe stator assembly (Fig. 120) is mounted on a sta- tionary shaft which is an integral part of the oil pump. The stator is located between the impeller and turbine within the torque converter case (Fig. 121). The stator contains an over-running clutch, which allows the stator to rotate only in a clockwise direc- tion. When the stator is locked against the over-run- ning clutch, the torque multiplication feature of the torque converter is operational.
DR
Fig.121StatorLocation
1 - STATOR 2 - IMPELLER 3 - FLUID FLOW 4 - TURBINE
Fig.122TorqueConverterClutch(TCC)
1 - IMPELLER FRONT COVER 2 - THRUST WASHER ASSEMBLY 3 - IMPELLER 4 - STATOR 5 - TURBINE 6 - PISTON 7 - FRICTION DISC
Fig.120StatorComponents
1 - CAM (OUTER RACE) 2 - ROLLER 3 - SPRING 4 - INNER RACE
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 122) was installed to improve the efficiency of the torque converter that is lost to the slippage of the fluid coupling. Although the fluid cou- pling provides smooth, shock-free power transfer, it is natural for all fluid couplings to slip. If the impeller and turbine were mechanically locked together, a zero slippage condition could be obtained. A hydraulic piston with friction material was added to the tur- bine assembly to provide this mechanical lock-up.
In order to reduce heat build-up in the transmission and buffer the powertrain against torsional vibrations, the TCM can duty cycle the L/R-CC Solenoid to achieve a smooth application of the torque converter clutch. This function, referred to as Electronically Modulated Converter Clutch (EMCC) can occur at various times depending on the following variables: † Shift lever position † Current gear range † Transmission fluid temperature † Engine coolant temperature † Input speed † Throttle angle † Engine speed
DR TORQUE CONVERTER (Continued) OPERATION
The converter impeller (Fig. 123) (driving member), which is integral to the converter housing and bolted to the engine drive plate, rotates at engine speed. The converter turbine (driven member), which reacts from fluid pressure generated by the impeller, rotates and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel- ler blades strikes the blades of the turbine, some of the energy and rotational force is transferred into the turbine and the input shaft. This causes both of them (turbine and input shaft) to rotate in a clockwise direction following the impeller. As the fluid is leav- ing the trailing edges of the turbine’s blades it con- tinues in a “hindering” direction back toward the impeller. If the fluid is not redirected before it strikes the impeller, it will strike the impeller in such a direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the stator’s over-running clutch to its shaft (Fig. 124). Under stall conditions (the turbine is stationary), the oil leaving the turbine blades strikes the face of the stator blades and tries to rotate them in a counter- clockwise direction. When this happens the over-run-
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 579
ning clutch of the stator locks and holds the stator from rotating. With the stator locked, the oil strikes the stator blades and is redirected into a “helping” direction before it enters the impeller. This circula- tion of oil from impeller to turbine, turbine to stator, and stator to impeller, can produce a maximum torque multiplication of about 2.4:1. As the turbine begins to match the speed of the impeller, the fluid that was hitting the stator in such as way as to cause it to lock-up is no longer doing so. In this con- dition of operation, the stator begins to free wheel and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and turbine are rotating at about the same speed and the stator is freewheeling, providing no torque multipli- cation. By applying the turbine’s piston and friction material to the front cover, a total converter engage- ment can be obtained. The result of this engagement is a direct 1:1 mechanical link between the engine and the transmission.
The clutch can be engaged in second, third, fourth, and fifth (if appicable) gear ranges depending on overdrive control switch position. If the overdrive control switch is in the normal ON position, the clutch will engage after the shift to fourth gear. If the
1 - APPLY PRESSURE 2 - THE PISTON MOVES SLIGHTLY FORWARD
3 - RELEASE PRESSURE 4 - THE PISTON MOVES SLIGHTLY REARWARD
Fig.123TorqueConverterFluidOperation-Typical
21 - 580
TORQUE CONVERTER (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
desired slip range of transmission input speed rela- tive to engine rpm.
GRADUAL-TO-NO EMCC
This operation is to soften the change from Full or Partial EMCC to No EMCC. This is done at mid- throttle by decreasing the L/R Solenoid duty cycle.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
Fig.124StatorOperation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL PUSHING ON BACKSIDE OF VANES 2 - FRONT OF ENGINE 3 - INCREASED ANGLE AS OIL STRIKES VANES 4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING AGAINST STATOR VANES
CAUTION: Verify that transmission is secure on the lifting device or work surface, the center of gravity of the transmission will shift when the torque con- verter is removed creating an unstable condition. The torque converter is a heavy unit. Use caution when separating the torque converter from the transmission.
control switch is in the OFF position, the clutch will engage after the shift to third gear.
The TCM controls the torque converter by way of internal logic software. The programming of the soft- ware provides the TCM with control over the L/R-CC Solenoid. There are four output logic states that can be applied as follows:
† No EMCC † Partial EMCC † Full EMCC † Gradual-to-no EMCC
NO EMCC
Under No EMCC conditions, the L/R Solenoid is OFF. There are several conditions that can result in NO EMCC operations. No EMCC can be initiated due to a fault in the transmission or because the TCM does not see the need for EMCC under current driving conditions.
PARTIAL EMCC
Partial EMCC operation modulates the L/R Sole- noid (duty cycle) to obtain partial torque converter clutch application. Partial EMCC operation is main- tained until Full EMCC is called for and actuated. During Partial EMCC some slip does occur. Partial EMCC will usually occur at low speeds, low load and light throttle situations.
FULL EMCC
During Full EMCC operation, the TCM increases the L/R Solenoid duty cycle to full ON after Partial EMCC control brings the engine speed within the
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive flats for sharp edges, burrs, scratches, or nicks. Polish the hub and flats with 320/400 grit paper or crocus cloth if neces- sary. Verify that the converter hub o-ring is properly installed and is free from debris. The hub must be smooth to avoid damaging the pump seal at installa- tion.
(1) Lubricate oil pump seal lip with transmission
(2) Place torque converter in position on transmis-
CAUTION: Do not damage oil pump seal or con- verter hub o-ring while inserting torque converter into the front of the transmission.
(3) Align torque converter to oil pump seal open-
(4) Insert torque converter hub into oil pump. (5) While pushing torque converter inward, rotate converter until converter is fully seated in the oil pump gears.
(6) Check converter seating with a scale and straightedge (Fig. 125). Surface of converter lugs should be at least 13 mm (1/2 in.) to rear of straight- edge when converter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle.
fluid.
sion.
ing.
DR TORQUE CONVERTER (Continued)
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 581
(9) Fill the transmission with the recommended
fluid.
TRANSMISSION RANGE SENSOR DESCRIPTION
The Transmission Range Sensor (TRS) is part of the solenoid module, which is mounted to the top of the valve body inside the transmission.
switch contact pins that:
The Transmission Range Sensor (TRS) has five † Determine shift lever position † Supply ground to the Starter Relay in Park and † Supply +12 V to the backup lamps in Reverse
Neutral only.
only.
The TRS also has an integrated temperature sen- communicates transmission
sor temperature to the TCM and PCM.
(thermistor)
that
Fig.125CheckingTorqueConverterSeating-Typical 1 - SCALE 2 - STRAIGHTEDGE
TRANSMISSION CONTROL RELAY DESCRIPTION
The relay is supplied fused B+ voltage, energized by the TCM, and is used to supply power to the sole- noid pack when the transmission is in normal oper- ating mode.
OPERATION
When the relay is “off”, no power is supplied to the solenoid pack and the transmission is in “limp-in” mode. After a controller reset, the TCM energizes the relay. Prior to this, the TCM verifies that the con- tacts are open by checking for no voltage at the switched battery terminals. After this is verified, the voltage at the solenoid pack pressure switches is checked. After the relay is energized, the TCM mon- itors the terminals to verify that the voltage is greater than 3 volts.
OPERATION
The Transmission Range Sensor (TRS) communi- cates shift lever position to the TCM as a combina- tion of open and closed switches. Each shift lever position has an assigned combination of switch states (open/closed) that the TCM receives from four sense circuits. The TCM interprets this information and determines the appropriate transmission gear posi- tion and shift schedule.
There are many possible combinations of open and closed switches (codes). Seven of these possible codes are related to gear position and five are recognized as “between gear” codes. This results in many codes which should never occur. These are called “invalid” codes. An invalid code will result in a DTC, and the TCM will then determine the shift lever position based on pressure switch data. This allows reasonably normal transmission operation with a TRS failure.
GEAR
Park
Temp 1
Reverse Temp 2
Neutral 1
Neutral 2
Temp 3
Drive Temp 4
Manual 2
Temp 5
Manual 1C5
CL CL OP OP OP OP OP OP OP CL CL CL
C4
OP OP OP OP OP CL CL CL CL CL OP OP
C3
OP OP OP CL CL CL CL CL OP OP OP CL
C2
CL CL CL CL CL CL CL OP OP OP OP OP
C1
CL OP OP OP CL CL OP OP OP OP OP OP
21 - 582
AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
TRANSMISSION SOLENOID/ TRS ASSEMBLY DESCRIPTION
The transmission solenoid/TRS assembly is inter- nal to the transmission and mounted on the valve body assembly (Fig. 126). The assembly consists of six solenoids that control hydraulic pressure to the six friction elements (transmission clutches), and the torque converter clutch. The pressure control sole- noid is located on the side of the solenoid/TRS assem- bly. The solenoid/TRS assembly also contains five pressure switches that feed information to the TCM.
The solenoids receive electrical power from the Transmission Control Relay through a single wire. The TCM energizes or operates the solenoids individ- ually by grounding the return wire of the solenoid as necessary. When a solenoid is energized, the solenoid valve shifts, and a fluid passage is opened or closed (vented or applied), depending on its default operat- ing state. The result is an apply or release of a fric- tional element.
The MS and UD solenoids are normally applied to allow transmission limp-in in the event of an electri- cal failure.
The continuity of the solenoids and circuits are periodically tested. Each solenoid is turned on or off depending on its current state. An inductive spike should be detected by the TCM during this test. If no spike is detected, the circuit is tested again to verify the failure. In addition to the periodic testing, the solenoid circuits are tested if a speed ratio or pres- sure switch error occurs.
PRESSURE SWITCHES
The TCM relies on five pressure switches to moni- tor fluid pressure in the L/R, 2C, 4C, UD, and OD hydraulic circuits. The primary purpose of these switches is to help the TCM detect when clutch cir- cuit hydraulic failures occur. The switches close at 23
psi and open at 11 psi, and simply indicate whether or not pressure exists. The switches are continuously monitored by the TCM for the correct states (open or closed) in each gear as shown in the following charts 45RFE PRESSURE SWITCH STATES and 545RFE PRESSURE SWITCH STATES :45RFE PRESSURE SWITCH STATES
GEAR
P/N 1ST 2ND 2ND PRIME
FOURTH
L/R
OP CL CL* OP
OP
OP OP
2C
OP OP OP CL
OP
OP OP
4C
OP OP OP OP
CL
OP CL
UD
OP OP CL CL
CL
CL OP
OD
OP OP OP OP
OP
CL CL
*L/R is closed if output speed is below 100 rpm in
Drive and Manual 2. L/R is open in Manual 1.
Fig.126TransmissionSolenoid/TRSAssembly
1 - PRESSURE CONTROL SOLENOID 2 - TRANSMISSION RANGE SELECTOR PLATE 3 - 23-WAY CONNECTOR 4 - SOLENOID PACK 5 - TRANSMISSION RANGE SENSOR 6 - VALVE BODY
OPERATION
SOLENOIDS
Solenoids are used to control the L/R, 2C, 4C, OD, and UD friction elements. The reverse clutch is con- trolled by line pressure and the position of the man- ual valve in the valve body. All the solenoids are contained within the Solenoid and Pressure Switch Assembly. The solenoid and pressure switch assembly contains one additional solenoid, Multi-Select (MS), which serves primarily to provide 2nd and 3rd gear limp-in operation.
DR TRANSMISSION SOLENOID/TRS ASSEMBLY (Continued)
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 583
545RFE PRESSURE SWITCH STATES
GEAR
P/N 1ST 2ND 2ND PRIME
4TH 5TH
L/R
OP CL CL* OP
OP
OP OP OP
2C
OP OP OP CL
OP
OP OP CL
4C
OP OP OP OP
CL
OP CL OP
UD
OP OP CL CL
CL
CL OP OP
OD
OP OP OP OP
OP
CL CL CL
*L/R is closed if output speed is below 100 rpm in
Drive and Manual 2. L/R is open in Manual 1.
A Diagnostic Trouble Code (DTC) will set if the TCM senses any switch open or closed at the wrong time in a given gear.
REMOVAL
(1) Remove the valve body from the transmission
(Fig. 127).
Fig.128TtransmissionSolenoid/TRSAssembly
1 - SOLENOID PACK BOLTS (15)
Screws
dowels are fully seated in the valve body and that the TRS switch contacts are properly positioned in the selector plate
(3) Install the screws to hold the transmission
solenoid/TRS assembly onto the valve body.
(4) Tighten the solenoid assembly screws adjacent to the arrows cast into the bottom of the valve body first. Tighten the screws to 5.7 N·m (50 in.lbs.).
(5) Tighten the remainder of the solenoid assembly
screws to 5.7 N·m (50 in.lbs.).
(6) Install the valve body into the transmission.
TRANSMISSION TEMPERATURE SENSOR DESCRIPTION
The transmission temperature sensor is a ther- mistor that is integral to the Transmission Range Sensor (TRS).
OPERATION
The transmission temperature sensor is used by the TCM to sense the temperature of the fluid in the sump. Since fluid temperature can affect transmis- sion shift quality and convertor lock up, the TCM requires this information to determine which shift schedule to operate in.
Calculated Temperature
A failure in the temperature sensor or circuit will result in calculated temperature being substituted for actual temperature. Calculated temperature is a pre-
Fig.127ValveBodyBolts
1 - VALVE BODY TO CASE BOLT (6)
(2) Remove the screws holding the transmission solenoid/TRS assembly onto the valve body (Fig. 128). (3) Separate the transmission solenoid/TRS assem-
bly from the valve body.
INSTALLATION
(1) Place TRS selector plate in the PARK position. (2) Position the transmission solenoid/TRS assem- bly onto the valve body. Be sure that both alignment
21 - 584
TRANSMISSION TEMPERATURE SENSOR (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
dicted fluid temperature which is calculated from a combination of inputs: † Battery (ambient) temperature † Engine coolant temperature † In-gear run time since start-up
VALVE BODY DESCRIPTION
The valve body consists of a cast aluminum valve body, a separator plate, and a transfer plate. The valve body contains valves and check balls that con- trol fluid delivery to the torque converter clutch, bands, and frictional clutches. The valve body con- tains the following components (Fig. 129) and (Fig. 130):† Solenoid switch valve † Manual valve † Low/reverse switch valve † 5 Accumulators † 7 check balls
Fig.130CheckBallLocations
1 - LOW/REVERSE ACCUMULATOR 2 - LOW/REVERSE SWITCH VALVE 3 - UPPER VALVE BODY 4 - MANUAL VALVE 5 - SOLENOID SWITCH VALVE
Fig.129ValveBodyComponents
6 - OVERDRIVE ACCUMULATOR 7 - UNDERDRIVE ACCUMULATOR 8 - 4C ACCUMULATOR 9 - 2C ACCUMULATOR
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 585
LOW/REVERSE SWITCH VALVE
The low/reverse switch valve allows the low/reverse clutch to be operated by either the LR/CC solenoid or the MS solenoid.
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. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/VALVE BODY - DISASSEMBLY)
(1) Shift transmission into PARK. (2) Raise vehicle. (3) Disconnect wires at the solenoid and pressure
switch assembly connector.
(4) Position drain pan under transmission oil pan. (5) Remove transmission oil pan. (6) Remove the primary oil filter from valve body.
(Fig. 132)
Fig.132RemovePrimaryOilFilter
1 - PRIMARY OIL FILTER 2 - COOLER RETURN FILTER 3 - COOLER RETURN FILTER BYPASS VALVE 4 - VALVE BODY
DR VALVE BODY (Continued) OPERATION
NOTE: Refer to the Hydraulic Schematics for a visual aid in determining valve location, operation and design.
SOLENOID SWITCH VALVE
The Solenoid Switch Valve (SSV) controls the direc- tion of the transmission fluid when the L/R-TCC sole- noid is energized.
When shifting into 1st gear, a special hydraulic sequence is performed to ensure SSV movement into the downshifted position. The L/R pressure switch is monitored to confirm SSV movement. If the move- ment is not confirmed (the L/R pressure switch does not close), 2nd gear is substituted for 1st. A DTC will be set after three unsuccessful attempts are made to get into 1st gear in one given key start.
MANUAL VALVE
The manual valve is a relay valve. The purpose of the manual valve is to direct fluid to the correct cir- cuit needed for a specific gear or driving range. The manual valve, as the name implies, is manually oper- ated by the driver with a lever located on the top of the valve body. The valve is connected mechanically by a cable to the gearshift mechanism. The valve is held in each of its positions by a roller detent spring (Fig. 131) that engages the “roostercomb” of the TRS selector plate.
Fig.131TRSSelectorPlateandDetentSpring
1 - TRS SELECTOR PLATE 2 - DETENT SPRING 3 - CLUTCH PASSAGE SEALS
21 - 586
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
(7) Remove bolts attaching valve body to transmis-
sion case (Fig. 133).
(8) Lower the valve body and work the electrical
connector out of transmission case.
(9) Separate the valve body from the transmission.
Fig.134SolenoidandPressureSwitchAssembly
1 - SOLENOID PACK BOLTS (15)
Screws
Fig.133ValveBodyBolts
1 - VALVE BODY TO CASE BOLT (6)
DISASSEMBLY
(1) Remove the screws holding the solenoid and pressure switch assembly to the valve body (Fig. 134). Do not remove the screws on the top of the sole- noid and pressure switch assembly.
(2) Separate the solenoid and pressure switch
assembly from the valve body.
(3) Remove the screw holding the detent spring
(Fig. 135) onto the valve body.
(4) Remove the detent spring from the valve body. (5) Remove the TRS selector plate from the valve
body and the manual valve.
(6) Remove the clutch passage seals from the valve
body, if necessary.
Fig.135ValveBodyExternalComponents
1 - TRS SELECTOR PLATE 2 - DETENT SPRING 3 - CLUTCH PASSAGE SEALS
DR VALVE BODY (Continued)
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 587
(7) Remove the screws holding the accumulator
cover onto the valve body (Fig. 136).
(8) Remove the accumulator springs and pistons from the valve body. Note which accumulator piston and spring belong in each location.
(9) Place the valve body on the bench with the
transfer plate upward.
NOTE: The valve body contains seven check balls. The transfer plate must be placed upward to pre- vent losing the check balls when the transfer plate is removed from the valve body.
(10) Remove the screws holding the valve body to
the valve body transfer plate.
(11) Remove the transfer plate from the valve body. Note the location of all check balls (Fig. 137). (12) Remove the check balls from the valve body.
Fig.137CheckBallLocations
1 - LOW/REVERSE ACCUMULATOR 2 - LOW/REVERSE SWITCH VALVE 3 - UPPER VALVE BODY 4 - MANUAL VALVE 5 - SOLENOID SWITCH VALVE
Fig.136ValveBodyComponents
6 - OVERDRIVE ACCUMULATOR 7 - UNDERDRIVE ACCUMULATOR 8 - 4C ACCUMULATOR 9 - 2C ACCUMULATOR
21 - 588
VALVE BODY (Continued)AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
(13) Remove the retainers securing the solenoid switch valve, manual valve, and the low/reverse switch valve into the valve body and remove the associated valve and spring. Tag each valve and spring combination with location information to aid in assembly. (Fig. 138)
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.
Fig.138ValveBodyComponents
1 - SOLENOID SWITCH VALVE 2 - MANUAL VALVE 3 - LOW REVERSE SWITCH VALVE 4 - LOW REVERSE ACCUMULATOR 5 - 2ND CLUTCH ACCUMULATOR 6 - UNDERDRIVE ACCUMULATOR 7 - OVERDRIVE ACCUMULATOR 8 - 4TH CLUTCH ACCUMULATOR 9 - CHECK BALLS (7)
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. (Fig. 139)
Do not immerse any of the electrical components in cleaning solution. Clean the electrical components by wiping them off with dry shop towels only.
Fig.139ValveBodyComponents
1 - SOLENOID SWITCH VALVE 2 - MANUAL VALVE 3 - LOW REVERSE SWITCH VALVE 4 - LOW REVERSE ACCUMULATOR 5 - 2ND CLUTCH ACCUMULATOR 6 - UNDERDRIVE ACCUMULATOR 7 - OVERDRIVE ACCUMULATOR 8 - 4TH CLUTCH ACCUMULATOR 9 - CHECK BALLS (7)
INSPECTION
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.
DR VALVE BODY (Continued)
AUTOMATIC TRANSMISSION - 45RFE/545RFE
21 - 589
Inspect
(Fig. 140)
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.
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.
Inspect all the accumulator 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 accumulator springs. The springs must be free of distortion, warpage or broken coils.
Inspect all the fluid seals on the valve body (Fig. 141). Replace any seals that are cracked, distorted, or damaged in any way. These seals pass fluid pressure directly to the clutches. Any pressure leak at these points, may cause transmission performance prob- lems.
Fig.140ValveBodyComponents
1 - SOLENOID SWITCH VALVE 2 - MANUAL VALVE 3 - LOW REVERSE SWITCH VALVE 4 - LOW REVERSE ACCUMULATOR 5 - 2ND CLUTCH ACCUMULATOR 6 - UNDERDRIVE ACCUMULATOR 7 - OVERDRIVE ACCUMULATOR 8 - 4TH CLUTCH ACCUMULATOR 9 - CHECK BALLS (7)
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.
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.
Fig.141ValveBodySeals
1 - UNDERDRIVE ACCUMULATOR (2 SPRINGS) 2 - 4TH CLUTCH ACCUMULATOR (2 SPRINGS) 3 - 2ND CLUTCH ACCUMULATOR (2 SPRINGS) 4 - LOW REVERSE ACCUMULATOR (2 SPRINGS) 5 - LOW/REVERSE PASSAGE SEAL 6 - 2ND CLUTCH PASSAGE SEAL 7 - 4TH CLUTCH PASSAGE SEAL 8 - OVERDRIVE ACCUMULATOR (1 SPRING)
(4) Install the valve body check balls into their
switch assembly connector with petroleum jelly.
AUTOMATIC TRANSMISSION - 45RFE/545RFE
DR
21 - 590
VALVE BODY (Continued) ASSEMBLY(1) Lubricate valves, springs, and the housing
valve bores with clean transmission fluid.
(2) Install solenoid switch valve, manual valve, and the low/reverse switch valve into the valve body. (3) Install the retainers to hold each valve into the
valve body.
proper locations.
(5) Position the transfer plate onto the valve body. (6) Install the screws to hold the transfer plate to the valve body. Tighten the screws to 5.6 N·m (50 in. lbs.).
(7) Install the accumulator pistons and springs into the valve body in the location from which they were removed. Note that all accumulators except the overdrive have two springs. The overdrive accumula- tor piston has only one spring.
(8) Position the accumulator cover onto the valve
body.
(9) Install the screws to hold the accumulator cover onto the valve body. Tighten the screws to 4.5
N·m (40 in. lbs.).(10) Install the TRS selector plate onto the valve
body and the manual valve.
(11) Install
the solenoid and pressure switch
assembly onto the valve body.
(12) Install the screws to hold the solenoid and pressure switch assembly onto the valve body. Tighten the screws to 5.7 N·m (50 in. lbs.). Tighten the screws adjacent to the arrows cast into the bot- tom of the transfer plate first.
(13) Position the detent spring onto the valve body. (14) Install the screw to hold the detent spring onto the valve body. Tighten the screw to 4.5 N·m (40
in. lbs.).(15) Install new clutch passage seals onto the
valve body, if necessary
INSTALLATION
(1) Check condition of seals on valve body and the solenoid and pressure switch assembly. Replace seals if cut or worn.
(2) Place TRS selector plate in the PARK position. (3) Place the transmission in the PARK position. (4) Lubricate seal on the solenoid and pressure
(5) Position valve body in transmission and align the manual lever on the valve body to the pin on the transmission manual shift lever.
(6) Seat valve body in case and install one or two
bolts to hold valve body in place.
(7) Tighten valve body bolts alternately and evenly
to 12 N·m (105 in. lbs.) torque.
(8) Install a new primary oil filter seal in the oil pump inlet bore. Seat the seal in the bore with the butt end of a hammer, or other suitable tool.
CAUTION: The primary oil filter seal MUST be fully installed flush against the oil pump body. DO NOT install the seal onto the filter neck and attempt to install the filter and seal as an assembly. Damage to the transmission will result.
(9) Place replacement filter in position on valve
body and into the oil pump.
(10) Install screw to hold filter to valve body.
Tighten screw to 4.5 N·m (40 in. lbs.) torque.
(11) Connect
the solenoid and pressure switch
assembly connector.
(105 in. lbs.) torque.
Mopart ATF +4.
(12) Install oil pan. Tighten pan bolts to 12 N·m
(13) Lower vehicle and fill
transmission with
(14) Check and adjust gearshift cable, if necessary.
DR
TRANSFER CASE - NV241 GENII
21 - 591
TRANSFER CASE - NV241 GENII
TABLE OF CONTENTS
page
page
TRANSFER CASE - NV241 GENII
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 616
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 591
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 591
DIAGNOSIS AND TESTING - TRANSFERCASE - NV241 GENII
. . . . . . . . . . . . . . . . . . 592
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 593
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 593
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 602
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 602
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 604
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 614
SPECIFICATIONSTRANSFER CASE - NV241 GENII
. . . . . . . . 614
SPECIAL TOOLS
TRANSFER CASE - NV241/NV243 . . . . . . . . 615
EXTENSION HOUSING BUSHING AND SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 616
TRANSFER CASE - NV241
GENII DESCRIPTIONThe NV241 GENII transfer case is a part-time transfer case with a low-range gear system. It pro- vides three operating ranges plus a NEUTRAL posi- tion. The low range position provides a gear reduction ratio of 2.72:1 for increased low speed torque capability.
The gear cases and extension are all of aluminum (Fig. 1). Drive sprockets and an interconnecting drive chain are used to transmit engine torque to the front/ rear propeller shafts. The mainshaft, input gear and front output shaft are supported by ball and needle bearings.
IDENTIFICATION
An identification tag (Fig. 2) is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio.
The transfer case serial number also represents
the date of build.
OPERATION
OPERATING RANGE
Transfer case operating ranges are: † 2H (2-wheel drive)
FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 617
FRONT OUTPUT SHAFT SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 618POSITION SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 618
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 619
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 619SHIFT LEVER
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 621
ADJUSTMENTSADJUSTMENT - SHIFT LEVER
. . . . . . . . . . 622
Fig.1TransferCase-FrontView
1 - TRANSFER CASE 2 - MANUAL LEVER 3 - POSITION SENSOR
† 4H (4-wheel drive) † 4LO (4-wheel drive low range The 2H range is for use on any road surface at any
time.
The 4H and 4LO ranges are for off road use only. They are not for use on hard surface roads. The only exception being when the road surface is covered by ice and snow.
The low range reduction gear system is operative in 4LO range only. This range is for extra pulling
21 - 592
TRANSFER CASE - NV241 GENII (Continued)TRANSFER CASE - NV241 GENII
DR
operates the range and mode forks within the trans- fer case.
A straight line shift pattern is used with a NEU- TRAL detent. Lever range positions are imprinted in the shift knob.
SHIFTING
The transfer case can be shifted between the 2H and 4H operating ranges while the vehicle is in motion. The vehicle must have the transmission placed in NEUTRAL, or the clutch depressed in the case of a manual transmission, and be moving less than 2-3 MPH when shifting into and out of the 4L operating range.
DIAGNOSIS AND TESTING - TRANSFER CASE - NV241 GENII
Before beginning repair on a suspected transfer case malfunction, check all other driveline compo- nents beforehand.
The actual cause of a problem may be related to such items as: front hubs, axles, propeller shafts, wheels and tires, transmission, or clutch instead. If all other driveline components are in good condition and operating properly, refer to the Diagnosis Chart for further information.
Fig.2TransferCase-RearView
1 - TRANSFER CASE 2 - IDENTIFICATION TAG
power in off road situations. Low range reduction ratio is 2.72:1.
SHIFT MECHANISM
The transfer case is operated by an adjustable floor mounted shift linkage. The transfer case shift lever is directly attached to the shift sector. The sector
DIAGNOSIS CHART
Condition
Possible Cause
Correction
Transfer Case difficult to shift or will not shift into desired range.
1) Vehicle speed too great to permit shifting.
2) If vehicle was operated for an extended period in 4H on a dry paved surface, the driveline torque load may be causing a bind.
3) Transfer case external shift linkage binding.
4) Insufficient or incorrect lubricant.
5) Internal components binding, worn, or damaged.
Transfer Case noisy in all operating ranges.
1) Insufficient or incorrect lubricant.
1) Stop vehicle and shift into desired range. Or, reduce speed to below 3-4 km/h (2-3 mph) before attempting the shift.
2) Stop vehicle and shift the transmission into neutral. Shift the transfer case to 2H and operate vehicle in 2H on dry paved surfaces. 3) Lubricate, repair, or replace linkage bushings, or tighten loose components as necessary. 4) Drain and refill to edge of fill hole with MoparT ATF +4, Automatic Transmission fluid. 5) Disassemble the transfer case and replace worn or damaged components as necessary.
1) Drain and refill to edge of fill hole with MoparT ATF +4, Automatic Transmission fluid.
DR TRANSFER CASE - NV241 GENII (Continued)
TRANSFER CASE - NV241 GENII
21 - 593
Condition
Possible Cause
Correction
Noisy in, or jumps out of, four wheel drive low range.
1) Transfer case not completely engaged in 4L position.
Lubricant leaking from output shaft seal or vent.
2) Shift linkage out of adjustment. 3) Shift linkage loose or binding.
4) Range fork damaged, inserts worn, or fork is binding on the shift rail. 5) Low range gear worn or damaged.
1) Transfer case overfilled.
2) Vent closed or restricted.
3) Output shaft seals damaged or installed incorrectly.
1) With the transmission in NEUTRAL, or the clutch depressed in the case of a manual transmission and the vehicle moving under 3-4 km/h (2-3 mph), shift the transfer case to NEUTRAL and then shift into the 4L position.
2) Adjust linkage. 3) Tighten, lubricate, or repair linkage as necessary. 4) Disassemble unit and repair as necessary.
5) Disassemble unit and repair as necessary.
1) Drain lubricant to the correct level.
2) Clear or replace vent as necessary. 3) Replace seal as necessary. Check to ensure that another component, the propeller shaft slip yoke for example, is not causing damage to seal.
Abnormal tire wear.
1) Extended operation on hard, dry surfaces in the 4H position.
1) Operate vehicle in the 2H position on hard, dry surfaces.
REMOVAL
(1) Raise and support vehicle. (2) Remove skid plate, if equipped. (Refer to 13 - FRAMES & BUMPERS/FRAME/TRANSFER CASE SKID PLATE - REMOVAL)
(3) Position drain oil container under transfer
case.
(4) Remove transfer case drain plug and drain
lubricant into container.
(5) Disconnect vent hose and transfer case position
sensor connector.
(6) Disconnect shift rod from grommet in transfer case shift lever, or from floor shift arm whichever provides easy access. Use channel lock style pliers to press rod out of lever grommet.
(7) Support transmission with jack stand. (8) Mark front and rear propeller shafts for assem-
bly reference.
(9) Remove front and rear propeller shafts. (Refer to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER SHAFT/PROPELLER SHAFT - REMOVAL)
(10) Support
transfer
case with suitable jack.
Secure transfer case to jack with safety chains.
(11) Remove nuts attaching transfer case to trans-
mission.
(12) Move transfer case assembly rearward until
free of transmission output shaft.
(13) Lower jack and move transfer case from
under vehicle.
DISASSEMBLY
Position transfer case in a shallow drain pan. Remove drain plug and drain any remaining lubri- cant remaining in case.
TRANSFER CASE - NV241 GENII
21 - 594
TRANSFER CASE - NV241 GENII (Continued) SHIFT LEVER AND FRONT OUTPUT SHAFT SEAL(1) Shift transfer case into NEUTRAL. (2) Remove nut that retains the shift lever to sec- tor shaft. Then remove shift lever from shaft (Fig. 3).
DR
Fig.5RemoveSealBoot
1 - SEAL BOOT 2 - SEAL SLINGER
Fig.3RemoveRangeLeverNut
1 - RANGE LEVER
(3) Remove the front propeller shaft seal boot
retaining clamp (Fig. 4).
(4) Remove the front propeller shaft seal boot (Fig.
5).
(5) Remove the front output shaft seal slinger by bending (Fig. 6) the slinger ears away from the transfer case.
Fig.6BendSlingerEars
1 - SLINGER 2 - BEND UPWARD
Fig.4RemoveBootClamp
1 - SEAL BOOT 2 - BOOT CLAMP
DR TRANSFER CASE - NV241 GENII (Continued)
TRANSFER CASE - NV241 GENII
21 - 595
(6) Using a suitable pry tool (Fig. 7), remove the slinger from the output shaft using care not to dam- age the shaft.
(2) Remove rear extension housing (Fig. 9). Tap extension once or twice with a plastic mallet to break sealer bead and loosen it.
Fig.7RemoveSlingerFromShaft
Fig.9RemoveRearExtension
1 - SLINGER 2 - PRY TOOL
