DODGE RAM 1999 Service Repair Manual

(1) - Approximate drive axle capacity listed. Lubricant level should
be within 1/2" below bottom of oil filler hole in axle housing
cover.
( 2) - Add container of Mopar Gear Oil Friction Modifier when
refilling.









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FLUID TYPE
Use SAE 80W-90 or SAE 90W hypoid gear lubricant with MIL-L-
2105-B and API GL-5 ratings. Also add a container of Mopar Gear Oil
Friction Modifier when refilling.
FLUID DRAIN & REFILL
1) With lubricant of rear axle assembly at normal operating
temperature, raise and support vehicle so rear wheels are free to
rotate. Clean around axle housing cover. Loosen axle housing cover
bolts. Drain lubricant from axle housing. Remove bolts and axle
housing cover.
2) Position differential so hole in differential case faces
down. Wipe all accessible areas of axle housing. Ensure sealing
surfaces on axle housing and cover are clean. Apply a 1/4" thick bead
of silicone sealant on inside of bolt holes and along sealing surfaces
on axle housing cover.
3) Install axle housing cover, axle identification tag and
retaining bolts. Tighten bolts to 30 ft. lbs. (41 N.m). Remove oil
filler plug. Add a container of Mopar Gear Oil Friction Modifier. Fill
axle with gear lube. Install oil filler plug. Lower vehicle.
TROUBLE SHOOTING
DIFFERENTIAL NOISE
1) Ensure differential lubricant is at normal operating
temperature. Road test vehicle. Note if differential noise exists in
turns, but not during straight-ahead driving. Probable cause is
incorrect or insufficient rear axle lubricant or additive.
2) Drain and refill rear axle. See FLUID DRAIN & REFILL under
LUBRICATION. Road test vehicle and note if noise still exists, it may
be necessary to disassemble rear axle so differential can be repaired.
See RBI FULL-FLOATING AXLES article for removal of differential case.
TESTING
NOTE: Power-Lok differential can be tested without removing
differential carrier from axle housing. Either test can be
used to check drive axle.
TEST I
1) Place blocks under both front wheels. Ensure engine is off
and transmission is in Neutral. Release parking brake. Raise one rear
wheel until it is completely clear of the floor. Remove wheel. Install
Adapter (6790) to wheel studs, and tighten securely.
2) Using torque wrench on adapter, rotate axle, and record
torque required. Repeat procedure for remaining rear wheel position.
If rotational torque for either rear wheel is less than 30 ft. lbs.
(41 N.m) or greater than 200 ft. lbs. (271 N.m), Power-Lok unit must\
be replaced or repaired.

TEST II
1) Drive vehicle until differential lubricant is at normal
operating temperature. Place a piece of Kraft paper over a smooth
Formica board. Place Formica board with Kraft paper under one rear
wheel. Rear wheel should be centered on board on level surface.
2) Block one front tire with a 2" high by 3" wide wooden
block. Start vehicle. With gradual throttle pressure, attempt to
slowly drive vehicle over wooden block.
3) If Kraft paper slips out from under rear wheel before
vehicle drives over wooden block, move Formica board and Kraft paper
under the other rear wheel.
4) With gradual throttle pressure, attempt to slowly drive
vehicle over wooden block again. If vehicle drives over wooden block
with Formica and Kraft paper under either rear wheel, drive axle is
functioning properly.
REMOVAL & INSTALLATION
Servicing procedure is same as that used for a standard
differential. See appropriate RBI FULL-FLOATING AXLES article for
servicing procedures.
OVERHAUL
DIFFERENTIAL CARRIER
CAUTION: Mark all component locations for reassembly reference. Note
position of clutch pack components before removal. Install
clutch pack components in correct order and original
locations.
Disassembly
1) Place reference mark on differential case lower half and
upper half for reassembly reference. Also place reference mark on
pinion cross shaft and differential case lower half for reassembly
reference.
2) Remove differential case half retaining bolts. Remove
differential case upper half. Remove components from differential case
lower half. See Fig. 1.
Fig. 1: Exploded View Of Power-Lok Differential
Courtesy of Chrysler Corp.
Cleaning & Inspection
Clean components with solvent, and dry with compressed air.

Inspect clutch components for scoring, wear or damage. Replace
components if necessary.
NOTE: If any clutch pack components are defective, replace both
clutch packs.
NOTE: Ensure axle shaft is positioned in vise so splines on axle
shaft extend approximately 3.00" (76.2 mm) above top of
vise.
Reassembly
1) Place axle shaft that was removed from differential in
soft-jaw vise with splines facing upward to serve as an alignment
device for component assembly.
2) Lubricate all components with gear lube. Assemble
components on axle shaft. Ensure all clutch plates are saturated with
gear lube. Install all clutch components and clutch ring on each side
gear. Ensure components are installed in proper sequence and in
original location. See Fig. 1.
3) Align all tabs on clutch plates, and secure with retaining
clips. Remove clutch component/side gear assembly from axle shaft.
Install assembly in differential case lower half. Ensure clutch is
fully seated in differential case lower half.
4) Install pinion cross shaft and pinion gears is
differential case lower half. Ensure reference marks on pinion cross
shaft and differential case lower half are aligned.
5) Install remaining clutch components and side gear on
differential case lower half. Install differential case upper half on
differential case lower half with reference marks aligned.
6) Install differential case half retaining bolts finger
tight. Place differential case assembly on axle shaft mounted in vise.
Ensure splines on axle shaft engage with side gear splines.
7) Install other axle shaft through differential case upper
half and into side gear. Ensure splines on axle shaft engage with side
gear splines. This must be done to ensure proper alignment of all
components.
NOTE: Different grade differential case half retaining bolts may be
used. Note number of radial lines on head of the bolt before
tightening bolts, as different torque specifications are
used.
8) Ensure both axle shafts are fully engaged. Tighten
differential case half bolts evenly in alternating pattern to
specification. See TORQUE SPECIFICATIONS table.
9) Remove axle shaft. Remove differential case assembly from
axle shaft in vise. Ensure pinion cross shaft is relatively tight on
its ramp. Clearance should not exceed .010" (.25 mm) and should be
equal at all 4 areas.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS








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Applications Ft. Lbs. (N.m)\
Axle Housing Cover Bolt .................................... 30 (41)\
Differential Case Half Bolt
7 Radial Lines Or No. 180 Stamp ................. 90-100 (122-136)\
All Others ......................................... 65-70 (88-95)\









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DRIV E A XLE - R BI F U LL F LO ATIN G A XLE

1999 D odge P ic ku p R 1500
1998-99 DRIVE AXLES
CHRY - RBI Full-Floating Axles
Ram Pickup, Ram Van/Wagon
IDENTIFICATION
REAR DRIVE AXLE APPLICATION








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Application Axle Ring Axle
Model Gear Size Ratio
Ram Pickup ....... 248 RBI .......... 9.75" ... 3.55:1 Or 4.10:1
Ram Pickup ....... 267 RBI ......... 10.50" ... 3.54:1 Or 4.10:1
Ram Pickup ....... 286 RBI ......... 11.00" ... 3.54:1 Or 4.10:1
Ram Van/Wagon .... 248 RBI .......... 9.75" ... 3.55:1 Or 4.10:1









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DESCRIPTION & OPERATION
The Rear Beam-Design Iron (RBI) axle is an iron center
casting (differential housing) with axle shaft tubes extending from
both sides. The tubes are pressed in to form a one-piece axle housing.
Axle contains an integral carrier with hypoid-type ring gear
and pinion with a solid full-floating axle shaft splined into side
gear. Vehicle weight is supported on tubes of axle housing. Axle
shafts may be serviced without disturbing wheel bearings. On vehicles
equipped with Rear Wheel Anti-Lock (RWAL) brakes, a brake sensor is
mounted on top of axle housing and an exciter ring is mounted on ring
gear.
Axles may be equipped with limited-slip differential. Models
248 and 286 RBI use a Trac-Lok differential and Model 267 RBI uses a
Power-Lok differential as optional equipment. Trac-Lok differential
uses a one-piece case. Power-Lok differential uses a 2-piece case.
Both differentials use same internal components as a standard
differential, except 2 clutch packs are used in the differential case.
NOTE: For servicing of limited-slip differential components in
differential case, see appropriate POWER-LOK or TRAC-LOK
article.
AXLE RATIO & IDENTIFICATION
NOTE: Axle ratio can be identified by axle identification tag
attached to axle housing cover. For axle ratio, see REAR
DRIVE AXLE APPLICATION table at beginning of article.
LUBRICATION
CAPACITY
DRIVE AXLE CAPACITY ( 1)








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Application Pts. (L)\
Ram Pickup
248 RBI ................................................ 6.3 (3.0)\

267 RBI ................................................ 7.0 (3.3)\
286 RBI
2WD ................................................... 6.8 (3.2)\
4WD .................................................. 10.1 (4.8)\
Ram Van/Wagon
248 RBI ................................................ 6.0 (2.8)\
(1) - Approximate drive axle capacity listed. Lubricant level should
be 1/2" below oil filler hole in axle housing cover.









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FLUID TYPE
Use SAE 80W-90 for 286 models, or 90W for all other models,
hypoid gear lubricant with MIL-L-2105-C and API GL-5 ratings. Models
with Trac-Lok require addition of 6 ozs. (.18 L) Mopar(R) friction
modifier (limited slip additive). Ram Pickups equipped with Power-Lok
require addition of 8 ozs. (.24 L) Mopar(R) friction modifier.
TROUBLE SHOOTING
NOTE: See appropriate table in TROUBLE SHOOTING article in GENERAL
INFORMATION.
REMOVAL & INSTALLATION
REAR HUB, BEARINGS & AXLE SHAFT
Removal
Raise and support vehicle. Remove wheel. Remove bolts, axle
shaft and gasket. Remove nut lock from adjusting nut. See Fig. 1.
Remove adjusting nut and outer wheel bearing. Remove rear hub and
brake drum. Remove oil seal and inner wheel bearing (if necessary).
Installation
1) Pack wheel bearings with wheel bearing grease. Install
inner wheel bearing and oil seal in rear hub (if removed). Install
rear hub and brake drum. Install outer wheel bearing and adjusting
nut. Tighten adjusting nut to specification while rotating rear hub
and brake drum. See TORQUE SPECIFICATIONS table.
2) Back off adjusting nut approximately 1/8 turn to obtain .
001-.010" (.03-.25 mm) wheel bearing end play. Tap key lock into
adjusting nut and keyway on axle housing.
3) To install remaining components, reverse removal
procedure. Use NEW gasket when installing axle shaft. Tighten bolts to
specification. See TORQUE SPECIFICATIONS table.
DRIVE SHAFT
Removal
1) Raise and support vehicle. Ensure transmission and
transfer case selector levers are in Neutral. Remove wheel assembly.
Remove RWAL sensor, if equipped. Reference mark drive shaft to pinion
flange for reassembly.
2) On 2-piece drive shafts, scribe center carrier bearing-to-
frame bracket reference line for reassembly. On all drive shafts,
remove bolts and "U" joint straps at pinion flange. Remove center
carrier bearing bolts, if equipped. Remove spring clamps and brackets.
Remove drive shaft(s).
CAUTION: The "U" joint straps and bolts must be replaced. DO NOT

reuse.
Installation
To install, reverse removal procedure using NEW "U" joint
straps and bolts. Ensure all reference marks are aligned. Tighten
bolts to specification. See TORQUE SPECIFICATIONS table.
PINION FLANGE & OIL SEAL
Removal
1) Raise and support vehicle. Reference mark drive shaft to
pinion flange on differential for reassembly. Remove bolts and "U"
joint straps at pinion flange on differential. Disconnect drive shaft
from differential, and support aside.
2) Using INCH-lb. torque wrench, measure amount of force
required to rotate pinion. This is pinion bearing preload. Record
pinion bearing preload for reassembly reference.
3) Remove pinion nut and washer from pinion. Scribe reference
mark on pinion flange and pinion for reassembly. Using Holder (6719)
and appropriate flange remover, remove pinion flange from pinion.
Remove oil seal from axle housing.
Installation
1) Ensure oil seal surface in axle housing is clean. Coat lip
of oil seal with gear lube. Using appropriate oil seal installer and
handle, install oil seal.
Fig. 1: Exploded View Of Rear Axle (Typical)
Courtesy of Chrysler Corp.
2) Install pinion flange on pinion with reference mark
aligned. Press pinion flange onto pinion. Install washer and pinion

nut. Tighten pinion nut while rotating pinion, ensuring bearings are
properly seated. Tighten nut until preload measured before disassembly
is achieved. DO NOT exceed maximum torque specification. See TORQUE
SPECIFICATIONS.
3) To install remaining components, reverse removal procedure
using NEW "U" joint straps and bolts. Ensure all reference marks are
aligned. Tighten bolts to specification. See TORQUE SPECIFICATIONS.
Check lubricant level and add if necessary.
AXLE HOUSING ASSEMBLY
NOTE: Removing axle housing assembly is not necessary unless axle
housing is damaged. Differential carrier and components can
be serviced by removing differential assembly from axle
housing.
Removal
1) Block brake pedal in upward position, as brake fluid lines
must be disconnected. Raise and support vehicle at body, in front of
rear springs. Remove rear wheels.
2) Reference mark drive shaft to pinion flange for
reassembly. Remove bolts and "U" joint straps at pinion flange. Remove
drive shaft, and support aside.
3) Disconnect and plug brakelines. Disconnect parking brake
cables. Disconnect shock absorbers. On models with Rear Wheel Anti-
Lock (RWAL) brakes, disconnect electrical connector at brake sensor on\
top of axle housing.
4) On all axles, support axle housing assembly with floor
jack. Remove rear spring "U" bolts. Lower axle housing assembly and
remove from vehicle.
Installation
1) To install, reverse removal procedure. Ensure rear spring
center bolts align with holes in spring pads on axle housing assembly.
2) Ensure reference marks on drive shaft and pinion flange
align. Tighten bolt/nuts to specification. See TORQUE SPECIFICATIONS.
Bleed and adjust brakes. Check axle fluid level and fill if necessary.
DIFFERENTIAL ASSEMBLY
NOTE: Differential assembly consists of differential case and
components mounted in axle housing. For differential assembly
servicing, see DIFFERENTIAL ASSEMBLY under OVERHAUL.
OVERHAUL
DIFFERENTIAL ASSEMBLY
Disassembly
1) On axles with Rear Wheel Anti-Lock (RWAL) brakes, remove
brake sensor from top of axle housing. On all axles, remove axle
shafts from differential. See REAR HUB, BEARINGS & AXLE SHAFT under
REMOVAL & INSTALLATION.
2) Note identification marks on bearing caps and axle housing
for reassembly reference. Bearing caps must be installed in original
location. If marks are not present, place marks on bearing caps and
axle housing.
3) Remove bearing caps. Place Axle Housing Spreader (W-129-B)\
on axle housing so dowel pins engage with locating holes. See Fig. 2.
Install hold-down clamps. Finger tighten turnbuckle on axle housing
spreader.
4) Install Guide Pin (C3288-B) at left side of axle housing.\

Install pilot stud and dial indicator onto axle housing. Position dial
indicator so stem is resting against opposite side of axle housing,
with pressure on stem.
5) Adjust dial indicator to zero. Tighten turnbuckle enough
to spread axle housing for differential case removal while noting
reading on dial indicator. Dial indicator reading should not exceed .
020" (.50 mm).
CAUTION: DO NOT spread axle housing more than .020" (.50 mm), or axle
housing may be damaged.
Fig. 2: Installing Axle Housing Spreader
Courtesy of Chrysler Corp.
6) Remove dial indicator. Pry differential case from axle
housing. If reusing bearing races for differential bearings, mark
bearing race location for reassembly reference. Bearing races must be
installed with same differential bearing.
7) If removing ring gear, place differential case in soft-jaw
vise. Remove and discard ring gear bolts. Using soft-face hammer, tap
ring gear from differential case.
8) On rear axles with Rear Wheel Anti-Lock (RWAL) brakes, us\
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soft-face hammer to tap exciter ring from differential case if
removing exciter ring. Replace exciter ring if removed from
differential case.
9) On all axles, remove pinion nut and washer from pinion.
Scribe reference mark on pinion flange and pinion if components are to
be reused. Disconnect drive shaft, and wire aside.
10) Using appropriate holder and flange remover, remove

pinion flange from pinion. Remove oil seal from axle housing.
11) Remove slinger (if equipped), pinion bearing and preload\
shim(s). See Fig. 1. Note thickness of preload shims for reassembly
reference in case shims become misplaced.
12) Remove pinion and bearing from axle housing. Using
appropriate remover, remove front (outer) pinion bearing race from
axle housing. Remove rear (inner) pinion bearing race from axle
housing using remover. Remove pinion bearing depth shims from axle
housing. See Fig. 1. Measure and record shim thickness for reassembly
reference.
13) Remove rear (inner) bearing from pinion, using
appropriate puller. Remove differential bearings from differential
case. Remove preload shims from differential case. See Fig. 1.
Identify preload shim location. Record preload shim thickness for
reassembly reference.
14) Clamp differential case in soft-jaw vise. Remove roll pin
from differential case. Tap pinion shaft from differential case.
Remove pinion gears, pinion gear thrust washers, side gears and side
gear thrust washers from differential case.
Cleaning & Inspection
1) Clean components with solvent and dry with compressed air.
Inspect components for wear. Inspect bearings and bearing races for
wear and pitting. Replace bearings and bearing races as a set. Inspect
ring gear and pinion teeth for wear and chipping. Replace ring gear
and pinion gear as matched set.
2) Check differential case for cracks or scoring of side
gears, thrust washers and pinion thrust faces. Check fit of side gears
to differential case and axle shaft splines. Examine shaft of pinion
shaft for scoring or excessive wear.
3) On axles with Rear Wheel Anti-Lock (RWAL) brakes, if
exciter ring is not removed from differential case, ensure exciter
ring fits tightly on differential case and is fully seated.
NOTE: Lubricate all bearings, bearing races, gears and thrust
washers with gear lube during reassembly.
Reassembly & Adjustments
1) Place differential case in soft-jaw vise. Install side
gears, side gear thrust washers, pinion gears and pinion gear thrust
washers into differential case.
2) Rotate side gears until holes in pinion gears and thrust
washers align with holes in differential case. Install pinion shaft.
Install roll pin in differential case. Stake edge of differential case
in 2 areas, 180 degrees apart, to retain roll pin in place. Remove
differential case from vise.
3) On rear axles with Rear Wheel Anti-Lock (RWAL) brakes,
align tab on exciter ring with slot on differential case if installing
exciter ring. Install ring gear on differential case. Install 2 NEW
ring gear bolts to maintain bolt hole alignment. Using press, press
exciter ring onto differential case using ring gear as a pilot.
4) Install ring gear on differential case (if not previously
installed). Install NEW ring gear bolts. Tighten bolts evenly in
alternating pattern to specification. See TORQUE SPECIFICATIONS table.
Proceed to INITIAL DIFFERENTIAL BEARING PRELOAD.
NOTE: Initial differential bearing preload must be performed to
determine thickness of preload shims in order to obtain zero
end play of differential case. Procedure must be performed
before installing pinion in axle housing.
Initial Differential Bearing Preload
1) Install master bearings on each side of differential case

where differential bearing fits. Use Dummy Bearing (D-343) for 248 and\
267 RBI axles, and (D-346) for 286 RBI axle.
2) Install differential case in axle housing. Install bearing
caps on axle housing. Ensure bearing caps are installed in original
location. Install bearing cap bolts.
3) Mount dial indicator on axle housing with stem against
back of ring gear. See Fig. 3. Pry between bearing cap and
differential case. Pry differential case to right as far as possible.
Zero dial indicator.
4) Pry differential case to left as far as possible. Note
dial indicator reading. This reading is referred to as differential
case zero end play. Record differential case zero end play reading.
5) Differential case zero end play measurement indicates
thickness of preload shims required to eliminate clearance between
differential bearings and bearing races.
6) Total thickness of preload shims will be determined during
ring gear backlash adjustment. Remove dial indicator, bearing caps and
differential case from axle housing. Proceed to PINION DEPTH
procedure.
Fig. 3: Measuring Differential Case End Play
Courtesy of Chrysler Corp.