1999 DODGE RAM Service Repair Manual

(inner) pinion bearing onto pinion until bearing is fully seated.
Install preload shims on pinion. Install pinion in axle housing.
Install front (outer) pinion bearing and slinger (if equipped).
Install pinion flange on pinion.
2) Using holder and Pinion Flange Installer (C-3716), press
pinion flange onto pinion. Install washer and used pinion nut. Tighten
pinion nut to specification. See TORQUE SPECIFICATIONS table.
3) Using INCH-lb. torque wrench, check torque required to
rotate pinion. This is pinion bearing preload. Ensure pinion bearing
preload is within specification. See AXLE ASSEMBLY SPECIFICATIONS.
4) If pinion bearing preload is not within specification,
adjust thickness of preload shims. Decrease shim thickness to increase
pinion bearing preload. Increase shim thickness to decrease pinion
bearing preload.
5) Remove nut and washer from pinion. Using holder and Pinion
Flange Remover (C-452), remove pinion flange from pinion. Ensure oil
seal surface in axle housing is clean.
6) Coat lip of oil seal with gear lube. Using appropriate oil
seal installer and handle, install oil seal.
7) Reinstall pinion flange, washer and NEW pinion nut. DO NOT
reuse pinion nut. Tighten pinion nut to specification. See TORQUE
SPECIFICATIONS table. Recheck pinion preload. Proceed to RING GEAR
BACKLASH.
NOTE: Before performing ring gear backlash, note differential case
zero end play obtained during initial differential bearing
preload. See INITIAL DIFFERENTIAL BEARING PRELOAD.
Ring Gear Backlash
1) Install dummy bearings on each side of differential case
where differential bearings fit. Use Dummy Bearing (D-345) for 216 FBI\
axle, or (D-343) for 248 FBI 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. Ensure pressure exists on stem of dial indicator.
Ensure ring gear and pinion are tightly meshed.
4) Pry between bearing cap and differential case. Pry
differential case as far to right as possible. Zero dial indicator.
5) Pry differential case to the left as far as possible, and
note reading on dial indicator. Repeat procedure several times to
ensure proper reading.
6) Measurement obtained determines preload shim thickness
required to eliminate ring gear backlash. Subtract reading obtained in
step 5) from differential case zero end play obtained during initial
differential bearing preload.
7) This is thickness of preload shims that must be installed
on ring gear side of differential case. These preload shims will be
referred to as the "ring gear backlash preload shims".
8) Remaining preload shims required to equal the differential
case zero end play will be referred as zero end play preload shims.
9) Remove dial indicator, bearing caps and differential case
from axle housing. Remove master bearings from differential case.
Install ring gear backlash preload shims on ring gear side of
differential case.
10) Install differential bearing on ring gear side of
differential case using appropriate bearing installer.
11) Install zero end play preload shims plus an additional .
015" (.38 mm) thick preload shim on differential case (opposite ring
gear side). Using bearing installer, install differential bearing on
differential case.
12) Install bearing races on differential bearings. If

reusing original differential bearings and bearing races, ensure
bearing races are installed in original locations.
13) Place axle housing spreader on axle housing so dowel pins
engage with locating holes. See Fig. 1. Use Axle Housing Spreader (W-
129-B). Install hold-down clamps. Tighten turnbuckle on axle housing
spreader finger tight.
14) Install pilot stud and dial indicator on axle housing.
See Fig. 1 . Position dial indicator so stem is resting against
opposite side of axle housing, with pressure on stem.
CAUTION: DO NOT spread axle housing more than .020" (.50 mm), or axle
housing may be damaged.
15) 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).
16) Remove dial indicator. Install differential case and
bearing races in axle housing. Ensure differential bearings and races
are fully seated. Remove axle housing spreader.
17) Install bearing caps in original location. Install
bearing cap bolts, and tighten to specification. See TORQUE
SPECIFICATIONS table. Rotate differential case several times to seat
differential bearings.
18) Using dial indicator, check ring gear backlash. See
Fig. 6 . Ensure ring gear backlash is as specified. See AXLE ASSEMBLY
SPECIFICATIONS.
19) If ring gear backlash exceeds specification, move ring
gear toward pinion. If ring gear backlash is less than specification,
move ring gear away from pinion. To change ring gear backlash, move
preload shims from one side of differential case to other.
20) Check ring gear backlash every 90 degrees to check for
variation. Ring gear backlash variation should not exceed .002" (.05
mm). For example, if ring gear backlash is .005" (.15 mm) at minimum
point, ring gear backlash should not exceed .008" (.20 mm) anywhere on\
ring gear.
Final Inspection & Assembly
1) With ring gear backlash properly adjusted, check gear
tooth pattern contact. See GEAR TOOTH CONTACT PATTERNS article in
GENERAL INFORMATION.
2) When differential is complete and correctly adjusted,
install axle housing cover using NEW gasket (if equipped). If gasket
is not available, 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 specification. See TORQUE
SPECIFICATIONS table. Fill differential with gear lube. See
LUBRICATION.
Fig. 6: Checking Ring Gear Backlash
Courtesy of Chrysler Corp.

AXLE ASSEMBLY SPECIFICATIONS
AXLE ASSEMBLY SPECIFICATIONS








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Application Specification
Ring Gear Backlash ......................... .005-.008" (.13-.20 mm)\
Ring Gear Backlash Variation .................... ( 1) .002" (.05 mm)
Pinion Bearing Preload
New Bearings ........................... 15-35 INCH Lbs. (2-5 N.m)\
Used Bearings .......................... 10-20 INCH Lbs. (1-2 N.m)\
( 1) - Maximum variation from ring gear backlash measured at
minimum point on ring gear. If ring gear backlash is
.005" (.15 mm) at minimum point, ring gear backlash should
not exceed .007" (.18 mm) anywhere on ring gear.









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TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS








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Applications Ft. Lbs. (N.m)\
ABS Sensor Bolt ................................................ ( 1)
Axle Nut ................................................. 175 (237)\
Ball Joint Stud Nut
216 FBI
Lower .................................................. 80 (109)\
Upper .................................................. 75 (102)\
248 FBI
Lower
1st Time .............................................. 35 (48)\
2nd Time .................................... 140-160 (190-217)\
Upper ................................................... 70 (95)\
Bearing Cap Bolt .......................................... 80 (109)\
Differential Cover Bolt .................................... 30 (41)\
Pinion Nut
216 FBI ........................................ 160-200 (217-271)\
248 FBI ........................................ 215-280 (292-380)\
Ring Gear Bolt
216 FBI ........................................... 70-90 (95-122)\
248 FBI ........................................ 120-140 (163-190)\
Shift Motor Mounting Bolt ...................................... ( 1)
Wheel Bearing Nut ........................................ 125 (170)\
( 1) - Tighten nuts to 96 INCH lbs. (11 N.m).









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DRIV E A XLE S - P O W ER -L O K

1999 D odge P ic ku p R 1500
1998-99 DRIVE AXLES
CHRY - Power-Lok
Ram Pickup
IDENTIFICATION
POWER-LOK DIFFERENTIAL APPLICATION








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Application Axle Ring Axle
Model Gear Size Ratio
Ram Pickup ........ Rear Axle ... 10.5" (266.7 mm) ..... 267 RBI\









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NOTE: For rear axles with limited-slip differentials, see TRAC-LOK
article.
DESCRIPTION & OPERATION
A Rear Beam-Design Iron (RBI) axle is an iron casting axle
and differential housing with axle shaft tubes extending from either
side. Tubes are pressed to form a one-piece full-floating axle
housing.
Power-Lok differential assembly is optional equipment. The
differential assembly is a limited-slip type differential. It is
similar in operation to a conventional type differential, except for 2
clutch packs located at the side gears in the differential case. See
Fig. 1 . Clutch packs provide differential action when required for
turning corners, and transmit equal torque to both wheels when driving
straight ahead.
AXLE RATIO & IDENTIFICATION
Axle ratio can be identified by axle identification tag
attached to axle housing cover. See AXLE RATIO SPECIFICATIONS table.
AXLE RATIO SPECIFICATIONS









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Application Ratio
Ram Pickup ......................................... 3.54:1 & 4.10:1









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WARNING: Whenever rotating wheels, DO NOT use engine to rotate
individual wheels unless both rear wheels are off ground and
vehicle is securely supported.
LUBRICATION
CAPACITY
DRIVE AXLE CAPACITY ( 1)








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Application Pts. (L)\
Ram Pickup ........................................... ( 2) 7.0 (3.3)

(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)\