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+4, Automatic Transmission Fluid. 4) Repair or replace components as necessary.


1) Drain and refill transfer case with the correct quantity of MoparT ATF +4, type 9602, Automatic Transmission Fluid. 2) Repair or replace components as necessary.


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 689


Condition


Possible Cause


Correction


Transfer case noisy while in, or jumps out of, 4LO mode.


1) Transfer case not completely engaged in 4LO position.


2) Range fork damaged, inserts worn, or fork is binding on the shift rail. 3) Low range gear worn or damaged. 1) Transfer case overfilled.


2) Transfer case vent closed or restricted. 3) Transfer case seals damaged or installed incorrectly. 1) Extended operation in 4HI mode on dry surfaces,


Lubricant leaking from transfer case seals or vent.


Abnormal tire wear.


REMOVAL


1) While rolling 2-3 MPH and the transmission in NEUTRAL, or clutch depressed on vehicles equipped with a manual transmission, shift transfer case to the 2WD or 4HI position, and then back into the 4LO position. 2) Repair or replace components as necessary.


3) Repair or replace components as necessary. 1) Drain lubricant to the correct level. 2) Clean or replace vent as necessary. 3) Replace suspect seal.


1) Operate vehicle in 2WD mode on dry surfaces.


(1) Shift transfer case into 2WD. (2) Raise vehicle. (3) Drain transfer case lubricant. (4) Mark front and rear propeller shafts for align-


(5) Support transmission with jack stand. (6) Remove


transfer


case


the


skid plate,


if


(7) Disconnect front and rear propeller shafts at


ment reference.


equipped.


transfer case.


(8) Disconnect transfer case shift motor and mode


sensor wire connectors.


(9) Disconnect transfer case vent hose. (10) Support transfer case with transmission jack. (11) Secure transfer case to jack with chains. (12) Remove nuts attaching transfer case to trans-


mission (Fig. 2).


gage transfer case.


(13) Pull transfer case and jack rearward to disen-


(14) Remove 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.


Fig.2RemoveTransferCase-Typical


1 - TRANSMISSION 2 - TRANSFER CASE 3 - MODE SENSOR CONNECTOR


TRANSFER CASE - NV273


21 - 690
TRANSFER CASE - NV273 (Continued) COMPANION FLANGE AND EXTENSION HOUSING


DR


(1) Install two bolts 180° apart into the front out-


put shaft companion flange.


(2) Place holder over the bolts and against the


companion flange (Fig. 3).


(3) Remove and discard the front companion flange


nut.


(4) Remove the companion flange from the front output shaft. It may be necessary to use Flange puller 8992 to remove the companion flange.


Fig.3RemoveCompanionFlangeNut-Typical


1 - HOLDER 6719
2 - BOLTS


(5) Use a suitable chisel or pry tool to remove the


rear extension housing dust boot (Fig. 4).


(6) Use a suitable chisel or pry tool to remove the


rear extension housing seal.


(7) Remove rear extension bolts (Fig. 5).


Fig.4RemoveExtensionHousingDustBoot


1 - EXTENSION HOUSING 2 - DUST BOOT


Fig.5RemoveExtensionHousingBolts


1 - EXTENSION HOUSING 2 - BOLTS


DR TRANSFER CASE - NV273 (Continued)


(8) Remove rear extension housing (Fig. 6). Tap extension once or twice with a plastic mallet to break sealer bead and loosen it.


TRANSFER CASE - NV273


21 - 691


Fig.8RemoveOilPump


1 - REAR CASE HALF 2 - REAR OUTPUT SHAFT 3 - OIL PUMP


(3) Remove rear case-to-front case bolts (Fig. 9).


Fig.6RemoveExtensionHousing


1 - REAR CASE HALF 2 - EXTENSION HOUSING


OIL PUMP AND REAR CASE


(1) Disengage the oil pump pick-up tube (Fig. 7)


from the oil pump.


NOTE: The oil pump pick-up tube seals to the oil pump with an o-ring. Verify that the o-ring was removed with the tube and is in good condition. Replace the o-ring if necessary.


(2) Remove the oil pump (Fig. 8).


Fig.9RemoveCaseHalfBolts


1 - FRONT CASE HALF 2 - REAR CASE HALF 3 - BOLTS


Fig.7DisengageTheOilPick-upFromOilPump 1 - OIL PUMP 2 - OIL PICK-UP TUBE


21 - 692
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


DR


(4) Remove the rear output shaft bearing inner snap-ring (Fig. 10) from the output shaft using suit- able snap-ring pliers.


(5) Remove the rear output shaft bearing inner


snap-ring (Fig. 11) from the output shaft.


(6) Loosen rear case with pry tool to break sealer


bead. Insert tool at each end of case (Fig. 12).


Fig.12SeparateFrontandRearCaseHalves


1 - FRONT CASE HALF 2 - REAR CASE HALF


(8) Remove the rear case from the front case (Fig.


13).


Fig.10RemoveRearBearingInnerSnap-Ring


1 - OUTPUT SHAFT 2 - REAR CASE HALF 3 - SNAP-RING


Fig.13RemoveRearCaseHalf


1 - FRONT CASE HALF 2 - REAR CASE HALF


Fig.11RemoveRearBearingInnerSnap-Ring


1 - OUTPUT SHAFT 2 - REAR CASE HALF 3 - SNAP-RING


(7) Unseat rear case from alignment dowels.


DR TRANSFER CASE - NV273 (Continued) FRONT OUTPUT SHAFT AND DRIVE CHAIN


(1) Remove the oil pick-up tube (Fig. 14) and


screen from the front case half.


TRANSFER CASE - NV273


21 - 693


Fig.14RemoveOilPick-UpTubeandScreen


1 - REAR OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING


Fig.16RemoveRearOutputShaftSprocket


RetainingRing


1 - FRONT CASE HALF 2 - OIL SCREEN 3 - PICK-UP TUBE


(2) Remove the front output shaft drive sprocket


retaining ring (Fig. 15).


retaining ring (Fig. 16).


(3) Remove the rear output shaft drive sprocket


(4) Pull front sprocket (Fig. 17), rear sprocket, and chain upward until clear of the front and rear output shaft sprocket splines.


(5) Remove chain and sprockets as an assembly.


Fig.15RemoveFrontOutputShaftSprocket


RetainingRing


1 - FRONT OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING


Fig.17RemoveDriveChainandSprockets


1 - FRONT CASE HALF 2 - CHAIN 3 - DRIVE SPROCKETS


TRANSFER CASE - NV273


21 - 694
TRANSFER CASE - NV273 (Continued) SHIFT FORKS AND MAINSHAFT


(1) Remove the bolts (Fig. 18) that hold the shift


motor assembly to the transfer case.


(2) Remove the shift motor assembly (Fig. 19) from


the transfer case.


DR


(3) Remove the sector support with Socket 9033. (4) Loosen detent plug (Fig. 20). (5) Remove detent plug, spring, and plunger (Fig. 21). Note that the plug has an O-ring seal. Remove and discard this seal.


Fig.18RemoveShiftMotorAssemblyBolts


Fig.20LoosentheDetentPlug


1 - TRANSFER CASE 2 - SHIFT MOTOR ASSEMBLY 3 - BOLTS


1 - FRONT CASE HALF 2 - DETENT PLUG


Fig.19RemoveShiftMotorAssemblyFrom


TransferCase


1 - TRANSFER CASE 2 - SHIFT MOTOR ASSEMBLY


Fig.21RemoveDetentplug,Spring,andPlunger 1 - FRONT CASE HALF 2 - DETENT PLUG 3 - SPRING 4 - PLUNGER


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 695


(6) Using a screw mounted in a slide hammer,


remove the front output shaft seal.


(7) Remove the front output shaft snap-ring (Fig.


22).


(9) Pull mainshaft assembly out of


mode sleeve, and case (Fig. 24).


input gear,


Fig.22RemoveFrontOutputShaftBearingInner


Snap-Ring


1 - FRONT CASE HALF 2 - SNAP-RING


(8) Remove front output shaft from bearing in case


(Fig. 23).


Fig.24RemoveMainshaftAssembly


1 - FRONT CASE HALF 2 - MAINSHAFT ASSEMBLY


(10) Remove mode fork, mode sleeve, and shift rail as assembly (Fig. 25). Note which way the sleeve fits in the fork (long side of sleeve goes to front or the points on the sleeve teeth go to the rear of case).


Fig.23RemoveFrontOutputShaft


1 - FRONT CASE 2 - FRONT OUTPUT SHAFT


Fig.25ModeForkAndSleeveRemoval


1 - MODE SLEEVE 2 - MODE FORK AND RAIL


21 - 696
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


(11) Remove range fork and hub as an assembly (Fig. 26). Note fork position for installation reference.


(12) Remove the shift sector (Fig. 27).


DR


MAINSHAFT


(1) Remove the clutch gear (Fig. 28) from the out-


put shaft.


Fig.26RangeForkAndHubRemoval


Fig.28RemoveClutchGear


1 - RANGE HUB 2 - RANGE FORK


1 - OUTPUT SHAFT 2 - CLUTCH GEAR 3 - MODE HUB


(2) Remove the mode hub retaining ring (Fig. 29)


from the mainshaft.


shaft.


(3) Remove the mode hub (Fig. 30) from the main-


Fig.27RemoveShiftSector


1 - SHIFT SECTOR


Fig.29RemoveModeHubRetainingRing


1 - MAINSHAFT 2 - MODE HUB 3 - RETAINING RING


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 697


Fig.32RemoveInputGearRetainingRing


1 - INPUT GEAR 2 - RETAINING RING


(3) Place front case in horizontal position. Then remove input gear and low range gear as an assem- bly (Fig. 33). Tap gear out of bearing with plastic mallet, if necessary.


Fig.30RemoveModeHub


1 - MAINSHAFT 2 - MODE HUB


(4) Remove the drive sprocket drive hub (Fig. 31)


from the mainshaft.


Fig.33RemoveInputPlanetaryAssembly


1 - FRONT CASE 2 - INPUT PLANETARY ASSEMBLY


Fig.31RemovetheDriveSprocketDriveHub


1 - MAINSHAFT 2 - DRIVE SPROCKET DRIVE HUB


INPUT AND PLANETARY GEAR


(1) Remove input gear seal with suitable screw


and slide hammer.


(2) Remove input gear retaining ring (Fig. 32) with


heavy duty snap-ring pliers.


21 - 698
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


DR


(4) Remove snap-ring that retains input gear in


the low range gear (Fig. 34).


(5) Remove retainer (Fig. 35). (6) Remove front thrust plate (Fig. 36).


Fig.36RemoveInputGearThrustPlate


1 - INPUT GEAR 2 - THRUST PLATE


Fig.34RemoveInputGearRetainingRing


1 - INPUT GEAR 2 - RETAINING RING


Fig.35RemoveInputGearRetainer


1 - INPUT GEAR 2 - RETAINER


(7) Remove input gear (Fig. 37). (8) Remove bottom tabbed thrust washer from low


range planetary (Fig. 38).


Fig.37RemoveInputGearFromPlanetary


1 - INPUT GEAR 2 - LOW RANGE PLANETARY


CLEANING


Clean the transfer case parts with a standard parts cleaning solvent. Remove all traces of sealer from the cases and retainers with a scraper and 3M™ all purpose cleaner. Use compressed air to remove solvent residue from oil feed passages in the case halves, retainers, gears, and shafts.


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 699


INSPECTION


MAINSHAFT/SPROCKET/HUB INSPECTION


Inspect the splines on the hub and shaft and the teeth on the sprocket. Minor nicks and scratches can be smoothed with an oilstone. However, replace any part that is damaged.


Check the contact surfaces in the sprocket bore and on the mainshaft. Minor nicks and scratches can be smoothed with 320-400 grit emery cloth but do not try to salvage the shaft if nicks or wear is severe.


INPUT GEAR AND PLANETARY CARRIER


Fig.38RemoveBottomInputGearThrustPlate


1 - PLANETARY 2 - THRUST PLATE


Check the teeth on the gear (Fig. 39). Minor nicks can be dressed off with an oilstone but replace the gear if any teeth are broken, cracked, or chipped. The bearing surface on the gear can be smoothed with 300-400 grit emery cloth if necessary.


Examine the carrier body and pinion gears for wear or damage. Check the pinion gear thrust wash- ers on the pinon pins for damage. The carrier will have to be replaced as an assembly if the body, pin- ion pins, or pinion gears are damaged.


Check the lock ring and both thrust washers for wear or cracks. Replace them if necessary. Also replace the lock retaining ring if bent, distorted, or broken.


1 - PLANETARY CARRIER 2 - REAR THRUST WASHER 3 - FRONT THRUST WASHER


Fig.39InputGearAndCarrierComponents 4 - CARRIER LOCK RING 5 - CARRIER LOCK RETAINING RING 6 - INPUT GEAR


TRANSFER CASE - NV273


21 - 700
TRANSFER CASE - NV273 (Continued) SHIFT FORKS/HUBS/SLEEVES


REAR EXTENSION HOUSING


DR


Check condition of the shift forks and mode fork shift rail (Fig. 40). Minor nicks on the shift rail can be smoothed with 320-400 grit emery cloth.


Inspect the extension housing seal and bushing. Replace both components if either show any sign of wear or damage.


FRONT OUTPUT SHAFT AND DRIVE CHAIN


Inspect the shaft threads, sprocket teeth, and bear- ing surfaces. Minor nicks on the teeth can be smoothed with an oilstone. Use 320-400 grit emery to smooth minor scratches on the shaft bearing sur- faces. Rough threads on the shaft can be chased if necessary. Replace the shaft if the threads are dam- aged, bearing surfaces are scored, or if any sprocket teeth are cracked or broken.


Examine the drive chain and shaft bearings. Replace the chain and both sprockets if the chain is stretched, distorted, or if any of the links bind. Replace the bearings if rough, or noisy.


LOW RANGE ANNULUS GEAR


Inspect annulus gear condition carefully. The gear is only serviced as part of the front case. If the gear is damaged, it will be necessary to replace the gear and front case as an assembly. Do not attempt to remove the gear (Fig. 42)


Fig.40ShiftForks


1 - RANGE FORK 2 - MODE FORK AND RAIL 3 - MODE SPRING


Inspect the shift fork wear pads (Fig. 41). The mode and range fork pads are serviceable and can be replaced if necessary.


Fig.41ShiftForkAndWearPadLocations


1 - RANGE FORK 2 - MODE FORK 3 - WEAR PADS (SERVICEABLE) 4 - WEAR PADS (SERVICEABLE)


Check both of the sleeves for wear or damage, especially on the interior teeth. Replace the sleeves if wear or damage is evident.


Fig.42LowRangeAnnulusGear


1 - FRONT CASE 2 - LOW RANGE ANNULUS GEAR


FRONT AND REAR CASES


Inspect the cases for wear and damage. Check case condition. If leaks were a problem, look for gouges and severe scoring of case sealing sur- faces. Also make sure the front case mounting studs are in good condition.


Check the front case mounting studs and vent tube. The tube can be secured with Loctite™ 271 or 680 if loose. The stud threads can be cleaned up with a die if necessary. Also check condition of the fill/ drain plug threads in the rear case. The threads can


TRANSFER CASE - NV273


21 - 701


DR TRANSFER CASE - NV273 (Continued)


be repaired with a thread chaser or tap if necessary. Or the threads can be repaired with Helicoilt stain- less steel inserts if required.


OIL PUMP/OIL PICKUP


Examine the oil pump pickup parts. Replace the pump if any part appears to be worn or damaged. Do not disassemble the pump as individual parts are not available. The pump is only available as a complete assembly. The pickup screen, hose, and tube are the only serviceable parts and are available separately.


ASSEMBLY


BEARINGS AND SEALS


(1) Remove the input shaft bearing snap-ring from


the front case half with suitable snap-ring pliers.


(2) Remove the input shaft bearing from the front case half with Installer 6953 and Handle C-4171
(Fig. 43).


(3) Install the input shaft bearing into the front case half with Installer 8151 inverted on Handle C-4171 (Fig. 44).


(4) Install the input shaft bearing snap-ring into


the front case half with suitable snap-ring pliers.


Fig.44InstallInputGearBearing


1 - FRONT CASE HALF 2 - HANDLE C-4171
3 - INSTALLER 8151 (INVERTED)


Fig.43RemoveInputGearBearing


1 - FRONT CASE HALF 2 - HANDLE C-4171
3 - INSTALLER 6953


Fig.45RemoveFrontOutputShaftFrontBearing 1 - FRONT CASE HALF 2 - HANDLE C-4171
3 - INSTALLER 6953


(5) Remove the front output shaft front bearing


snap-ring from the front case half.


(6) Using Installer 6953 and Handle C-4171 (Fig.


45), remove the front output shaft front bearing.


21 - 702
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


DR


(7) Start front output shaft front bearing in case.


Then seat bearing with Installer 8891 (Fig. 46).


(8) Install


front output shaft bearing retaining


ring.


(10) Install new pilot bearing with Installer 9035. (11) Remove the front output shaft rear bearing with the screw and jaws from Remover L-4454 and Cup 8148 (Fig. 48).


(12) Install new bearing with Tool Handle C-4171
and Installer 8128 (Fig. 49). The bearing bore is


Fig.46InstallFrontOutputShaftFrontBearing


1 - FRONT CASE HALF 2 - INSTALLER 8891


(9) Remove input gear pilot bearing by inserting a suitably sized drift into the splined end of the input gear and driving the bearing out with the drift and a hammer (Fig. 47).


Fig.48FrontOutputShaftRearBearingRemoval 1 - REAR CASE 2 - SPECIAL TOOL L-4454-1 AND L-4454-3
3 - SPECIAL TOOL 8148


Fig.47RemoveInputGearCupBearing


1 - DRIFT 2 - INPUT GEAR


1 - REAR CASE HALF 2 - HANDLE C-4171
3 - INSTALLER 8128


Fig.49InstallFrontOutputShaftRearBearing


DR TRANSFER CASE - NV273 (Continued)


chamfered at the top. Install the bearing so it is flush with the lower edge of this chamfer (Fig. 50).


TRANSFER CASE - NV273


21 - 703


Fig.50OutputShaftRearBearingInstallationDepth 1 - BEARING (SEATED) AT LOWER EDGE OF CHAMFER 2 - CHAMFER


Fig.52RemoveRearOutputBearingOuter


Snap-Ring


(13) Remove seal from oil pump with suitable pry


(14) Install new seal in oil pump with Installer


tool.


7888 (Fig. 51).


Fig.51OilPumpSealInstallation


1 - HOUSING SEAL 2 - SPECIAL TOOL 7888
3 - OIL PUMP FEED HOUSING


(15) Remove the rear output shaft bearing snap-


ring (Fig. 52) from the rear case half.


(16) Remove the rear output shaft bearing from


the rear case using Installer 7888 (Fig. 53).


1 - REAR CASE HALF 2 - REAR OUTPUT SHAFT BEARING 3 - SNAP-RING


Fig.53RemoveRearOutputShaftBearing


1 - REAR CASE HALF 2 - INSTALLER 7888


21 - 704
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


DR


(17) Install the rear output shaft bearing (Fig. 54) into the rear case using Installer 8152 and Handle C-4171.


(18) Install the rear output shaft bearing snap-


ring into the rear case half.


Fig.54InstallRearOutputShaftBearing


1 - REAR CASE HALF 2 - HANDLE C-4171
3 - INSTALLER 8152


INPUT AND PLANETARY GEAR


(1) Lubricate gears and thrust washers with rec-


ommended transmission fluid.


(2) Install bottom thrust washer (Fig. 55) in low range gear planetary. Be sure washer tabs are prop- erly aligned in gear notches.


(3) Install input gear in low range gear (Fig. 56).


Be sure input gear is fully seated.


Fig.55InstallBottomInputGearThrustPlate


1 - PLANETARY 2 - THRUST PLATE


Fig.56InstallInputGearFromPlanetary


1 - INPUT GEAR 2 - LOW RANGE PLANETARY


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 705


(4) Install remaining thrust washer (Fig. 57) in


low range gear and on top of input gear.


(5) Install retainer (Fig. 58) on input gear and


install snap-ring (Fig. 59).


Fig.59InstallInputGearRetainingRing


1 - INPUT GEAR 2 - RETAINING RING


Fig.57InstallInputGearThrustPlate


1 - INPUT GEAR 2 - THRUST PLATE


Fig.60InstallInputPlanetaryAssembly


1 - FRONT CASE 2 - INPUT PLANETARY ASSEMBLY


Fig.58InstallInputGearRetainer


1 - INPUT GEAR 2 - RETAINER


(6) Align and install low range/input gear assem- bly in front case (Fig. 60). Be sure low range gear pinions are engaged in annulus gear and that input gear shaft is fully seated in front bearing.


21 - 706
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


DR


(7) Install snap-ring to hold input/low range gear


(3) Install the mode hub (Fig. 63) onto the main-


into front bearing (Fig. 61).


8841 and Handle C-4171.


shaft.


onto the mainshaft.


(8) Install a new input gear seal using Installer


(4) Install the mode hub retaining ring (Fig. 64)


Fig.61InstallInputGearRetainingRing


1 - INPUT GEAR 2 - RETAINING RING


(9) Install a new input gear oil seal with Installer


9036 and Handle C-4171.


SHIFT FORKS AND MAINSHAFT


(1) Lubricate mainshaft splines with recommended


transmission fluid.


(2) Coat the interior of the drive sprocket hub with ATF+4 and install the drive sprocket drive hub (Fig. 62) onto the mainshaft.


Fig.63InstallModeHub


1 - MAINSHAFT 2 - MODE HUB


Fig.62InstalltheDriveSprocketDriveHub


1 - MAINSHAFT 2 - DRIVE SPROCKET DRIVE HUB


Fig.64InstallModeHubRetainingRing


1 - MAINSHAFT 2 - MODE HUB 3 - RETAINING RING


DR TRANSFER CASE - NV273 (Continued)


(5) Install the clutch gear (Fig. 65) onto the output shaft. Verify that the pointed ends of the clutch gear teeth are pointing to the front of the mainshaft.


TRANSFER CASE - NV273


21 - 707


(9) Align and insert range fork pin in shift sector


slot.


Fig.67InstallRangeForkAndHubAssembly


1 - RANGE HUB 2 - RANGE FORK


(10) Install mode fork and shift rail onto the mode


sleeve.


(11) Install the mode fork, sleeve, and shift rail


into the transfer case (Fig. 68).


Fig.65InstallClutchGear


1 - OUTPUT SHAFT 2 - CLUTCH GEAR 3 - MODE HUB


(6) Lubricate sector shaft with transmission fluid and install shift sector in case (Fig. 66). Position slot in sector so it will be aligned with shift fork pin when shift forks are installed.


(7) Apply Loctite™ 242, or equivalent,


to the threads of the sector support to replentish the factory applied patch. support. Tighten the sector support with Socket 9033 to 27-34
N·m (20-25 ft.lbs.).


the shift


Install


sector


Fig.68ModeForkAndSleeveInstallation


1 - MODE SLEEVE 2 - MODE FORK AND RAIL


Fig.66InstallShiftSector


1 - SHIFT SECTOR


(8) Assemble and install range fork and hub (Fig. 67). Be sure hub is properly seated in low range gear and engaged to the input gear.


21 - 708
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


(12) Install new o-ring on detent plug (Fig. 69). (13) Install detent plunger, spring, and plug (Fig.


70). Tighten the plug to 16-25 N·m (12-18 ft. lbs.).


DR


Fig.69O-RingInstallationOnDetentPlug


1 - O-RING 2 - DETENT PLUG


Fig.71InstallShiftMotorAssemblyOntoTransfer


Case


1 - TRANSFER CASE 2 - SHIFT MOTOR ASSEMBLY


Fig.70InstallDetentplug,Spring,andPlunger


1 - FRONT CASE HALF 2 - DETENT PLUG 3 - SPRING 4 - PLUNGER


(1) Position the shift motor and mode sensor


assembly (Fig. 71) onto the transfer case.


(2) Install the bolts (Fig. 72) to hold the shift motor and mode sensor assembly to the transfer case. Tighten the bolts to 16-25 N·m (12-18 ft. lbs.).


Fig.72InstallShiftMotorAssemblyBolts


1 - TRANSFER CASE 2 - SHIFT MOTOR ASSEMBLY 3 - BOLTS


DR TRANSFER CASE - NV273 (Continued)


(3) Install mainshaft into the transfer case (Fig. 73). Guide mainshaft through the mode and range sleeves and into the input gear.


TRANSFER CASE - NV273


21 - 709


Fig.73InstallMainshaftAssembly


1 - FRONT CASE HALF 2 - MAINSHAFT ASSEMBLY


FRONT OUTPUT SHAFT AND DRIVE CHAIN


(1) Install the front output shaft (Fig. 74) into the


front output shaft front bearing.


(2) Install the front output shaft bearing inner


snap-ring (Fig. 75) onto the output shaft.


(3) Install the new front output shaft seal with


Installer MB991168A


Fig.75InstallFrontOutputShaftBearingInner


Snap-Ring


1 - FRONT CASE HALF 2 - SNAP-RING


(6) Position rear drive sprocket (Fig. 76) over the output shaft and lower the sprocket and chain assembly until the front sprocket is positioned over the front output shaft.


(7) Align the splines in the sprockets to the splines on the output shafts and install the sprockets onto the output shafts.


Fig.74InstallFrontOutputShaft


1 - FRONT CASE 2 - FRONT OUTPUT SHAFT


(4) Insert front drive sprocket in drive chain. (5) Install drive chain around rear drive sprocket.


Fig.76InstallDriveChainandSprockets


1 - FRONT CASE HALF 2 - CHAIN 3 - DRIVE SPROCKETS


21 - 710
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


(8) Install front sprocket retaining ring (Fig. 77). (9) Install rear sprocket retaining ring (Fig. 78).


DR


Fig.79CaseMagnetInstallation


1 - MAGNET 2 - CASE POCKET


(2) Apply bead of Mopart Gasket Maker, or equiv- alent, to mating surface of front case. Keep sealer bead width to maximum of 3/16 inch. Do not use excessive amount of sealer as excess will be displaced into case interior.


(3) Align mainshaft with the rear output shaft bearing and align shift rail with bore in rear case. Then install rear case (Fig. 80). Verify that the case alignment dowels correctly seat into their mating recesses.


Fig.77InstallFrontOutputShaftSprocket


RetainingRing


1 - FRONT OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING


Fig.78InstallRearOutputShaftSprocketRetaining


Ring


1 - FRONT CASE HALF 2 - REAR CASE HALF


Fig.80InstallRearCaseHalf


1 - REAR OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING


(10) Insert magnet in front case pocket (Fig. 79).


REAR CASE


(1) Install the oil pick-up tube and screen into the


rear case half.


TRANSFER CASE - NV273


21 - 711


DR TRANSFER CASE - NV273 (Continued)


(4) Install 4-5 rear case-to front case bolts (Fig. 81) to hold rear case in position. Tighten bolts snug but not to specified torque at this time.


CAUTION: Verify that shift rail, and case alignment dowels are seated before installing any bolts. Case could be cracked if shaft rail or dowels are mis- aligned.


(5) Tighten bolts to 27-34 N·m (20-25 ft. lbs.), (6) Install rear output bearing inner snap-ring


(Fig. 82) to output shaft.


Fig.82InstallRearBearingInnerSnap-Ring


1 - OUTPUT SHAFT 2 - REAR CASE HALF 3 - SNAP-RING


Fig.81InstallCaseHalfBolts


1 - FRONT CASE HALF 2 - REAR CASE HALF 3 - BOLTS


OIL PUMP AND REAR EXTENSION


(1) Install the oil pump (Fig. 83) onto the output


shaft.


Fig.83InstallOilPump


1 - REAR CASE HALF 2 - REAR OUTPUT SHAFT 3 - OIL PUMP


21 - 712
TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


(2) Engage the oil pump pick-up tube (Fig. 84) into the oil pump. Verify that the pick-up tube o-ring is on the tube and is correctly installed to the oil pump. (3) Apply bead of Mopart Gasket Maker, or equiv-


DR


(5) Install rear extension bolts (Fig. 86). Tighten


the bolts to 27-34 N·m (20-25 ft.lbs.).


Fig.84EngageTheOilPick-upToOilPump


1 - EXTENSION HOUSING 2 - BOLTS


Fig.86InstallExtensionHousingBolts


1 - OIL PUMP 2 - OIL PICK-UP TUBE


alent, to mating surface of rear extension housing. Keep sealer bead width to maximum of 3/16 inch. Do not use excessive amount of sealer as excess could be displaced into output bearing.


(4) Install extension housing (Fig. 85) onto the


rear case half.


(6) Install the extension housing dust boot and seal assembly with Installer 9037 and Handle C-4171
(Fig. 87).


Fig.85InstallExtensionHousing


1 - REAR CASE HALF 2 - EXTENSION HOUSING


Fig.87InstallExtensionHousingSeal


1 - EXTENSION HOUSING 2 - HANDLE C-4171
3 - INSTALLER 9037


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 713


(7) Install the front companion flange onto the


front output shaft.


(8) Install two bolts 180° apart into the front out-


put shaft companion flange.


(9) Place holder over the bolts and against the


companion flange (Fig. 88).


(10) Install a new front companion flange nut. Tighten the companion flange nut to 176-271 N·m (130-200 ft.lbs.).


INSTALLATION


(1) Mount transfer case on a transmission jack. (2) Secure transfer case to jack with chains. (3) Position transfer case under vehicle. (4) Align transfer case and transmission shafts


and install transfer case onto the transmission.


(5) Install and tighten transfer case attaching nuts


to 27-34 N·m (20-25 ft. lbs.) torque.


(6) Connect the vent hose. (7) Connect the shift motor and mode sensor wir- ing connectors. Secure wire harness to clips on trans- fer case.


(8) Align and connect the propeller shafts. (9) Fill transfer case with correct fluid. (Refer to 21 - TRANSMISSION/TRANSFER CASE/FLUID - STANDARD PROCEDURE)


(10) Install skid plate, if equipped.


Fig.88InstallCompanionFlangeNut


1 - HOLDER 6719
2 - BOLTS


(11) Remove transmission jack and support stand. (12) Lower vehicle and verify transfer case shift


operation.


SPECIFICATIONS


TRANSFER CASE - NV273


TORQUE SPECIFICATIONS


DESCRIPTION


Plug, Detent Plug, Drain/Fill


Bolt, Extension Housing


Bolt, Case Half Support, Sector Nuts, Mounting


Bolts, Shift Motor and Mode Sensor Assembly Nut, Companion Flange


N-m 16-24
20-34
27-34
27-34
27-34
30-41
16-25


176-271


Ft. Lbs. 12-18
15-25
20-25
20-25
20-25
20-30
12-18


130-200


In. Lbs.


TRANSFER CASE - NV273


21 - 714
TRANSFER CASE - NV273 (Continued) SPECIAL TOOLS


TRANSFER CASE NV271/NV273


DR


Installer,Bearing-8128


Handle,Universal-C-4171


Cup-8148


Installer-8151


Installer-8152


Remover-L-4454


Installer,Bearing-6953


Installer,PumpHousingSeal-7888


DR TRANSFER CASE - NV273 (Continued)


TRANSFER CASE - NV273


21 - 715


Installer-8891


Installer,Seal-9036


Socket-9033


Installer,Seal-9037


Installer,Bearing-9035


21 - 716


TRANSFER CASE - NV273


DR


EXTENSION HOUSING SEAL AND DUST BOOT REMOVAL


(1) Raise and support vehicle. (2) Remove rear propeller shaft. (Refer to 3 - DIF- FERENTIAL & DRIVELINE/PROPELLER SHAFT/ PROPELLER SHAFT - REMOVAL)


(3) Use a suitable chisel or pry tool to remove the


rear extension housing dust boot (Fig. 89).


(4) Use a suitable chisel or pry tool to remove the


rear extension housing seal.


Fig.90InstallExtensionHousingSeal


1 - EXTENSION HOUSING 2 - HANDLE C-4171
3 - INSTALLER 9037


Fig.91DrainandFillLocations


1 - FILL HOLE 2 - DRAIN HOLE


(2) Position drain pan under transfer case. (3) Remove drain and fill plugs and drain lubri-


(4) Install drain plug. Tighten plug to 41-54 N·m


cant completely.


(30-40 ft. lbs.).


(5) Remove drain pan.


Fig.89RemoveExtensionHousingDustBoot


1 - EXTENSION HOUSING 2 - DUST BOOT


INSTALLATION


(1) Clean fluid residue from sealing surface and


inspect for defects.


(2) Install the extension housing dust boot and seal assembly with Installer 9037 and Handle C-4171
(Fig. 90).


(3) Install propeller shaft. (Refer to 3 - DIFFER- ENTIAL & DRIVELINE/PROPELLER SHAFT/PRO- PELLER SHAFT - INSTALLATION)


(4) Verify proper transfer case fluid level. (5) Lower vehicle.


FLUID STANDARD PROCEDURE - FLUID DRAIN AND REFILL


The fill and drain plugs are both in the rear case


(Fig. 91).


(1) Raise vehicle.


TRANSFER CASE - NV273


21 - 717


(6) Using a screw and a slide hammer, remove the


front output shaft seal.


INSTALLATION


(1) Install the new front output shaft seal with


Installer MB991168A.


front output shaft.


(2) Install the front companion flange onto the


(3) Install two bolts 180° apart into the front out-


put shaft companion flange.


(4) Place holder over the bolts and against the


companion flange (Fig. 93).


(5) Install a new front companion flange nut. Tighten the companion flange nut to 258-312 N·m (190-230 ft.lbs.).


DR FLUID (Continued)


(6) Fill transfer case to bottom edge of fill plug opening with Mopart ATF +4, Automatic Transmis- sion fluid.


(7) Install and tighten fill plug to 41-54 N·m


(30-40 ft. lbs.).


(8) Lower vehicle.


FRONT OUTPUT SHAFT SEAL REMOVAL


(1) Remove the front propeller shaft (Refer to 3 - DRIVELINE/PROPELLER


DIFFERENTIAL SHAFT/PROPELLER SHAFT - REMOVAL).


(2) Install two bolts 180° apart into the front out-


put shaft companion flange.


(3) Place holder over the bolts and against the


companion flange (Fig. 92).


(4) Remove and discard the front companion flange


nut.


(5) Remove the companion flange from the front output shaft. It may be necessary to use Flange puller 8992 to remove the companion flange.


Fig.93InstallCompanionFlangeNut


1 - HOLDER 6719
2 - BOLTS


(6) Install front propeller shaft (Refer to 3 - DIF- FERENTIAL & DRIVELINE/PROPELLER SHAFT/ PROPELLER SHAFT - INSTALLATION).


Fig.92RemoveCompanionFlangeNut


1 - HOLDER 6719
2 - BOLTS


21 - 718


TRANSFER CASE - NV273


DR


MODE SENSOR DESCRIPTION


The transfer case mode sensor (Fig. 94) is an elec- tronic device whose output can be interpreted to indi- cate the shift motor shaft’s rotary position. The sensor consists of a magnetic ring and four Hall Effect Transistors to create a 4 channel digital device (non-contacting) whose output converts the motor shaft position into a coded signal. The TCCM must supply 5VDC (+/- 0.5v) to the sensor and monitor the shift motor position. The four channels are denoted A, B, C, and D. The sensor is mechanically linked to the shaft of the cam which causes the transfer case shifting. The mode sensor draws less than 53 mA.


OPERATION


During normal vehicle operation, the Transfer Case Control Module (TCCM) monitors the mode sensor outputs at least every 250 (+/-50) milliseconds when the shift motor is stationary and 400 microseconds when the shift motor is active. A mode sensor signal between 3.8 Volts and 0.8 Volts is considered to be undefined.


Refer to SECTOR ANGLES vs. TRANSFER CASE POSITION for the relative angles of the transfer case shift sector versus the interpreted transfer case gear operating mode. Refer to MODE SENSOR CHAN- NEL STATES for the sensor codes returned to the TCCM for each transfer case mode sensor position. The various between gears positions can also be referred as the transfer case’s coarse position. These coarse positions come into play during shift attempts.


Fig.94ModeSensor


1 - MODE SENSOR


SECTOR ANGLES VS. TRANSFER CASE POSITION


Shaft Angle (Degrees)


Transfer Case Position


+40
+20
-20


4LO


2WD/AWD


4HI


Transfer Case Angle (degrees) Between Gears


+40 (4LO)


Between Gears Between Gears +20 (NEUTRAL) Between Gears Between Gears 0 (2WD/AWD) Between Gears Between Gears


-20 (4HI)


Between Gears Between Gears


MODE SENSOR CHANNEL STATES


Sensor Channel A


Sensor Channel B


Sensor Channel C


Sensor Channel D


DR


TRANSFER CASE - NV273


21 - 719


SELECTOR SWITCH DESCRIPTION


The selector switch assembly (Fig. 95) is mounted in the left side of the vehicle’s Instrument Panel (IP) and consists of a rotary knob connected to a resistive network for the mode and range shift selections. Also located in this assembly is a recessed, normally open momentary switch for making shifts into and out of transfer case NEUTRAL. A pen, or similar instru- ment, is used to make a NEUTRAL shift selection, thus reducing the likelihood of an inadvertent shift request.


The selector switch also contains four light emit- ting diode’s (LED’s) to indicate the transfer case posi- tion and whether a shift is in progress.


OPERATION


As the position of the selector switch varies, the resistance between the Mode Sensor supply voltage pin and the Mode Sensor output will vary. Hardware, software, and calibrations within the Transfer Case Control Module (TCCM) are provided that interpret the selector switch resistance as given in the table below: SELECTOR SWITCH INTERPRETATION


SELECTOR SWITCH INTERPRETATION


Step


Resistance


Range (ohms)


Required


Interpretation


<200


400-700
1050-1450
1850-2300
3050-5950
9.5-12.5K


>15.5K


Shorted


NEUTRAL


4LO 4HI


2WD (Default)


In between positions


Open


Fig.95TransferCaseSelectorSwitch


1 - SELECTOR SWITCH


For resistances between the ranges B-E shown for each valid position (T-Case NEUTRAL, 4LO, 4HI, 2WD), the TCCM may interpret the resistance as:


† either of the neighboring valid positions. † as an invalid fault position. For resistances between the ranges E and F shown for 2WD and in-between positions, the TCCM may interpret the resistance as:


† the 2WD position. † an invalid fault position. † a valid in-between position. For resistances between the ranges F and G shown for in-between positions and fault condition (open), the TCCM may interpret the resistance as:


† a valid in-between position. † an invalid fault position. For resistances between the ranges A and B shown for the fault condition (short) and , T-Case NEU- TRAL, the TCCM may interpret the resistance as:


† the T-Case NEUTRAL position. † an invalid fault position. The LED’s in the selector assembly are illuminat- ed/flashed in the following manner to indicate a par- ticular condition or state. † A solidly illuminated LED indicates a success- fully completed shift and the current operating mode of the transfer case. While a shift has been requested but not yet completed, the LED for the desired trans- fer case position is flashed.


21 - 720
TRANSFER CASE - NV273
SELECTOR SWITCH (Continued) † A flashing operating mode LED for the desired gear indicates that a shift to that position has been requested, but all of the driver controllable conditions have not been met. This is in an attempt to notify the driver that the transmission needs to be put into NEUTRAL, the vehicle speed is too great, or some other condition outlined (other than a diagnostic fail- ure that would prevent this shift) elsewhere (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MOD- ULES/TRANSFER CASE CONTROL MODULE - OPERATION) is not met. Note that this flashing will continue indefinitely until the conditions are eventu- ally met, or the selector switch position is changed, or longer allow the if diagnostic requested shift. † If the driver attempts to make a shift into trans- fer case NEUTRAL, and any of the driver controlla- ble conditions are not met, the request will be ignored until all of the conditions are met or until the NEUTRAL select button is released. Additionally the neutral lamp will flash, or begin to flash while the button is depressed and operator controllable conditions are not being met. All of the LED’s except the Neutral will flash if any of the operator control- lable conditions for shifting are not met while the Neutral button is depressed. This 9toggle9 type of fea- ture is necessary because the TCCM would interpret into another request transfer case NEUTRAL has completed. † No LED’s illuminated indicate a fault in the


immediately after the shift


routines no


transfer case control system.


SHIFT MOTOR DESCRIPTION


The shift motor (Fig. 96) consists of a permanent magnet D.C. motor with gear reduction to convert a high speed-low torque device into a low speed-high torque device. The output of the device is coupled to a shaft which internally moves the mode and range forks that change the transfer case operating ranges. The motor is rated at 25 amps maximum at 72° F with 10 volts at the motor leads.


OPERATION


The transfer case shift motor responds to the Transfer Case Control Module (TCCM) commands to move the transfer case shift sector bi-directionally, as required, to obtain the transfer case operating mode indicated by the instrument panel mounted selector switch.


DR


Fig.96ShiftMotor-ShownInverted-Typical


1 - SHIFT MOTOR


REMOVAL


(1) Raise the vehicle on a suitable hoist. (2) Disengage the wiring connectors from the shift


motor and mode sensor.


(3) Remove the bolts holding the shift motor and


mode sensor assembly onto the transfer case.


(4) Separate the shift motor and mode sensor


assembly from the transfer case.


INSTALLATION


(1) Verify that the shift sector o-ring is clean and properly positioned over the shift sector and against the transfer case.


(2) Position the shift motor and mode sensor


assembly onto the transfer case.


(3) Install the bolts to hold the assembly onto the transfer case. Tighten the bolts to 16-24 N·m (12-18
ft.lbs.).


CAUTION: If the original shift motor and mode sen- sor assembly bolts are reused, be sure to use MoparT Lock & Seal or Loctite™ 242 to replenish the lock patch material originally found on the bolts


(4) Engage the wiring connectors to the shift motor


and mode sensor.


(5) Refill the transfer case as necessary. (6) Lower vehicle and verify transfer case operation.


DR


TIRES/WHEELS


22 - 1


TIRES/WHEELS


TABLE OF CONTENTS


page


page


TIRES/WHEELS


DIAGNOSIS AND TESTING - TIRE AND


STANDARD PROCEDURE - REPAIRING


LEAKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


WHEEL RUNOUT


. . . . . . . . . . . . . . . . . . . . . . 1


SPECIFICATIONS


STANDARD PROCEDURE


TIRE REVOLUTIONS PER MILE


. . . . . . . . . . 10


STANDARD PROCEDURE - TIRE ROTATION . 2
STANDARD PROCEDURE - MATCH


MOUNTING . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


STANDARD PROCEDURE - TIRE AND


WHEEL BALANCE . . . . . . . . . . . . . . . . . . . . . . 4


TIRES


DESCRIPTION


DESCRIPTION - SPARE TIRE /


TEMPORARY . . . . . . . . . . . . . . . . . . . . . . . . . 5
DESCRIPTION - TIRES . . . . . . . . . . . . . . . . . . 5
DESCRIPTION - RADIAL – PLY TIRES . . . . . . 6
DESCRIPTION - TIRE PRESSURE FOR


HIGH SPEEDS. . . . . . . . . . . . . . . . . . . . . . . . . 6
DESCRIPTION - REPLACEMENT TIRES . . . . . 6
DESCRIPTION - TIRE INFLATION


PRESSURES . . . . . . . . . . . . . . . . . . . . . . . . . . 6


DIAGNOSIS AND TESTING


DIAGNOSIS AND TESTING - PRESSURE


GAUGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


DIAGNOSIS AND TESTING - TIRE NOISE


WHEELS


. . . . . . . . . . . . . . . . . . . . . . . . . 11
DESCRIPTION OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
DIAGNOSIS AND TESTING


WHEEL INSPECTION


. . . . . . . . . . . . . . . . . . 11


STANDARD PROCEDURE


STANDARD PROCEDURE - WHEEL


REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . 12


STANDARD PROCEDURE - DUAL REAR


WHEEL INSTALLATION . . . . . . . . . . . . . . . . . 12


SPECIFICATIONS


TORQUE CHART . . . . . . . . . . . . . . . . . . . . . . 13


STUDS


REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 14


WHEEL COVER


REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
INSTALLATION


INSTALLATION - REAR . . . . . . . . . . . . . . . . . 14
. . . . . . . . . . . . . . . . 15
INSTALLATION - FRONT


OR VIBRATION . . . . . . . . . . . . . . . . . . . . . . . . 7


SPARE TIRE


DIAGNOSIS AND TESTING - TREAD WEAR


DESCRIPTION


INDICATORS . . . . . . . . . . . . . . . . . . . . . . . . . . 7


DESCRIPTION - SPARE / TEMPORARY


DIAGNOSIS AND TESTING - TIRE WEAR


TIRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


PATTERNS . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


DESCRIPTION - FULL SIZE, SPARE WHEEL


DIAGNOSIS AND TESTING - TIRE/VEHICLE


LEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


TIRES/WHEELS DIAGNOSIS AND TESTING - TIRE AND WHEEL RUNOUT


Radial runout is the difference between the high


and low points on the tire or wheel (Fig. 1).


Lateral runout is the wobble of the tire or wheel. Radial runout of more than 1.5 mm (.060 inch) measured at the center line of the tread may cause the vehicle to shake.


Lateral runout of more than 2.0 mm (.080 inch) measured near the shoulder of the tire may cause the vehicle to shake.


Sometimes radial runout can be reduced. Relocate the wheel and tire assembly on the mounting studs (See Method 1). If this does not reduce runout to an


WITH MATCHING TIRE . . . . . . . . . . . . . . . . . 15


acceptable level, the tire can be rotated on the wheel. (See Method 2).


METHOD 1 (RELOCATE WHEEL ON HUB)


(1) Drive vehicle a short distance to eliminate tire


flat spotting from a parked position.


(2) Check wheel bearings and adjust if adjustable


or replace if necessary.


(3) Check the wheel mounting surface. (4) Relocate wheel on the mounting, two studs


over from the original position.


(5) Tighten wheel nuts until all are properly


torqued, to eliminate brake distortion.


(6) Check radial runout. If still excessive, mark tire sidewall, wheel, and stud at point of maximum runout and proceed to Method 2.


TIRES/WHEELS


22 - 2
TIRES/WHEELS (Continued)


DR


Fig.1CheckingTire/Wheel/HubRunout


Fig.2RadialRunout


1 - RADIAL RUNOUT 2 - LATERAL RUNOUT


METHOD 2 (RELOCATE TIRE ON WHEEL)


NOTE: Rotating the tire on wheel effective when there is runout wheel.


is particularly in both tire and


1 - MOUNTING CONE 2 - SPINDLE SHAFT 3 - WING NUT 4 - PLASTIC CUP 5 - DIAL INDICATOR 6 - WHEEL 7 - DIAL INDICATOR


(1) Remove tire from wheel and mount wheel on


service dynamic balance machine.


runout (Fig. 3).


(2) Check wheel radial runout (Fig. 2) and lateral † STEEL WHEELS: Radial runout 0.031 in., Lat- † ALUMINUM WHEELS: Radial runout 0.020 in.,


eral runout 0.031 in. (maximum)


Lateral runout 0.025 in. (maximum)


(3) If point of greatest wheel lateral runout is near original chalk mark, remount tire 180 degrees. Recheck runout, Refer to match mounting procedure.


STANDARD PROCEDURE


STANDARD PROCEDURE - TIRE ROTATION


Tires on the front and rear axles operate at differ- ent loads and perform different steering, driving, and braking functions. For these reasons, the tires wear at unequal rates. They may also develop irregular wear patterns. These effects can be reduced by rotat- ing the tires according to the maintenance schedule in the Owners Manual. This will improve tread life, traction and maintain a smooth quiet ride.


The recommended method of tire rotation is (Fig. 4) & (Fig. 5). Other methods can be used, but may not provide the same tire longevity benefits.


CAUTION: 3500 Dual rear tires have a new tire rota- tion pattern. This is to accommodate the asymmet-


Fig.3LateralRunout


1 - MOUNTING CONE 2 - SPINDLE SHAFT 3 - WING NUT 4 - PLASTIC CUP 5 - DIAL INDICATOR 6 - WHEEL 7 - DIAL INDICATOR


rical design of the ON/OFF road tires and the use of the outlined white letter (OWL) tires. When replac- ing a flat, the spare tire may have to be remounted on the rim or installed at a different location to maintain the correct placement of the asymmetrical design or the (OWL).


DR TIRES/WHEELS (Continued)


TIRES/WHEELS


22 - 3


Fig.4TIREROTATIONPATTERN-SINGLEREAR


WHEEL(SRW)


Fig.6FirstMeasurementOnTire


1 - REFERENCE MARK 2 - 1ST MEASUREMENT HIGH SPOT MARK TIRE AND RIM 3 - WHEEL 4 - VALVE STEM


(3) Break down the tire and remount it 180


degrees on the rim (Fig. 7).


Fig.5TIREROTATIONPATTERN-DUALREAR


WHEELS(DRW)


STANDARD PROCEDURE - MATCH MOUNTING Wheels and tires are match mounted at the factory. This means that the high spot of the tire is matched to the low spot on the wheel rim. Each are marked with a bright colored temporary label on the out- board surface for alignment. The wheel is also marked permanently on the inside of the rim in the tire well. This permanent mark may be a paint dot or line, a permanent label or a stamped impression such as an X. An optional location mark is a small spherical indentation on the vertical face of the out- board flange on some non styled base steel wheels. The tire must be removed to locate the permanent mark on the inside of the wheel.


Before dismounting a tire from its wheel, a refer- ence mark should be placed on the tire at the valve stem location. This reference will ensure that it is remounted in the original position on the wheel.


(1) Remove the tire and wheel assembly from the vehicle and mount on a service dynamic balance machine.


(2) Measure the total runout on the center of the tire tread rib with a dial indicator. Record the indi- cator reading. Mark the tire to indicate the high spot. Place a mark on the tire at the valve stem location (Fig. 6).


Fig.7RemountTire180Degrees


1 - VALVE STEM 2 - REFERENCE MARK


(4) Measure the total indicator runout again. Mark


the tire to indicate the high spot.


(5) If runout is still excessive, the following proce-


dures must be done.


TIRES/WHEELS


22 - 4
TIRES/WHEELS (Continued)


Fig.8RemountTire90DegreesInDirectionof


Arrow


1 - 2ND HIGH SPOT ON TIRE 2 - 1ST HIGH SPOT ON TIRE


† If the high spot is within 101.6 mm (4.0 in.) of the first spot and is still excessive, replace the tire. † If the high spot is within 101.6 mm (4.0 in.) of the first spot on the wheel, the wheel may be out of specifications. Refer to Wheel and Tire Runout. † If the high spot is NOT within 101.6 mm (4.0 in.) of either high spot, draw an arrow on the tread from second high spot to first. Break down the tire and remount it 90 degrees on rim in that direction (Fig. 8).


DR


This procedure will normally reduce the runout to an acceptable amount, if not replace the rim.


STANDARD PROCEDURE - TIRE AND WHEEL BALANCE


It


is recommended that a two plane service dynamic balancer be used when a tire and wheel assembly require balancing. Refer to balancer opera- tion instructions for proper cone mounting proce- dures. Typically use front cone mounting method for steel wheels. For aluminum wheel use back cone mounting method without cone spring.


NOTE: Static should be used only when a two plane balancer is not available.


NOTE: Cast aluminum and forged aluminum wheels require coated balance weights and special align- ment equipment.


Wheel balancing can be accomplished with either on or off vehicle equipment. When using on-vehicle balancing equipment, remove the opposite wheel/tire. Off-vehicle balancing is recommended.


For static balancing, find the location of the heavy spot causing the imbalance. Counter balance wheel directly opposite the heavy spot. Determine weight required to counter balance the area of imbalance. Place half of this weight on the inner rim flange and the other half on the outer rim flange (Fig. 9).


1 - HEAVY SPOT 2 - CENTER LINE OF SPINDLE 3 - ADD BALANCE WEIGHTS HERE


Fig.9StaticUnbalance&Balance


4 - CORRECTIVE WEIGHT LOCATION 5 - TIRE OR WHEEL TRAMP, OR WHEEL HOP


DR TIRES/WHEELS (Continued)


TIRES/WHEELS


22 - 5


1 - CENTER LINE OF SPINDLE 2 - ADD BALANCE WEIGHTS HERE


3 - CORRECTIVE WEIGHT LOCATION 4 - HEAVY SPOT WHEEL SHIMMY AND VIBRATION


Fig.10DynamicUnbalance&Balance


For dynamic balancing, the balancing equipment is designed to locate the amount of weight to be applied to both the inner and outer rim flange (Fig. 10).


TIRES


DESCRIPTION


DESCRIPTION - SPARE TIRE / TEMPORARY


The temporary spare tire is designed for emer- gency use only. The original tire should be repaired or replaced at the first opportunity, then reinstalled. Do not exceed speeds of 50 M.P.H. when using the temporary spare tire. Refer to Owner’s Manual for complete details.


DESCRIPTION - TIRES


Tires are designed and engineered for each specific vehicle. They provide the best overall performance for normal operation. The ride and handling charac- teristics match the vehicle’s requirements. With proper care they will give excellent reliability, trac- tion, skid resistance, and tread life.


Driving habits have more effect on tire life than any other factor. Careful drivers will obtain in most cases, much greater mileage than severe use or care- less drivers. A few of the driving habits which will shorten the life of any tire are: † Rapid acceleration † Severe brake applications


† High speed driving † Excessive speeds on turns † Striking curbs and other obstacles Radial-ply tires are more prone to irregular tread wear. It is important to follow the tire rotation inter- val shown in the section on Tire Rotation, (Refer to 22 - TIRES/WHEELS - STANDARD PROCEDURE). This will help to achieve a greater tread life.


TIRE IDENTIFICATION


Tire type, size, aspect ratio and speed rating are encoded in the letters and numbers imprinted on the side wall of the tire. Refer to the chart to decipher the tire identification code (Fig. 11).


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