DRIV E A XLE - F B I S EM I- F LO ATIN G
1999 D odge P ic ku p R 1500
1998-99 DRIVE AXLES
CHRY - FBI Semi-Floating Axles
Ram Pickup
IDENTIFICATION
DRIVE AXLE APPLICATION \
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Application Axle Ring Axle
Model Gear Size Ratio
Front Axle ........ 216 FBI ......... 8.50" .. 3.54, 3.92 & 4.09
Front Axle ........ 248 FBI ......... 9.75" ........ 3.54 & 4.10
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DESCRIPTION & OPERATION
The Front Beam-Design Iron (FBI) axles is of 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
and is a semi-floating design.
Axle contains an integral carrier with hypoid-type ring gear
and pinion with semi-floating axle shafts. Load is supported by hub
bearings. Axle shafts are retained by nuts at the hub bearings. Hub
bearings are bolted to steering knuckle at outboard end of axle tube
yoke. Hub bearings are serviced as an assembly. On vehicles equipped
with Anti-Lock (ABS) brakes, a brake sensor is mounted on knuckle
assemblies, and tone rings are pressed onto axle shaft.
Differential is a one-piece design and differential pinion
mate shaft is retained with a roll pin. Differential bearing preload
and ring gear backlash is adjusted by use of shims, and pinion bearing
preload is set and maintained by use of a collapsible spacer.
Axle shaft is engaged or disengaged by an axle vacuum shift
motor. Vacuum shift motor is operated by engine vacuum and is
controlled by a switch mounted on transfer case.
AXLE RATIO & IDENTIFICATION
NOTE: Axle ratio can be identified by axle identification tag
attached to axle housing cover. See IDENTIFICATION.
LUBRICATION
CAPACITY
DRIVE AXLE CAPACITY ( 1) \
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Application Pts. (L)\
216 FBI .................................................. 4.8 (2.3)\
248 FBI .................................................. 7.6 (3.6)\
(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 or 90W hypoid gear lubricant with MIL-L-2105-C
and API GL-5 ratings.
TROUBLE SHOOTING
NOTE: See appropriate table in TROUBLE SHOOTING article in GENERAL
INFORMATION.
REMOVAL & INSTALLATION
AXLE SHAFT & HUB BEARING
Removal
1) Raise and support vehicle. Remove wheel. Remove brake
caliper with hose attached, and secure aside. DO NOT allow brake
caliper to hang by brake hose. Remove brake rotor. Remove ABS wheel
speed sensor (if equipped). Remove grease cap from center of front
hub. Remove cotter pin from end of axle shaft. Remove axle nut and
washer.
2) Remove hub/bearing assembly-to-knuckle bolts. Remove
hub/bearing assembly from steering knuckle and axle shaft. Remove
brake dust shield. To remove right (passenger-side) axle shaft,
carefully pull axle shaft from axle housing.
NOTE: Left axle shaft will disengage from collar located on
intermediate axle shaft.
3) To remove left (driver's side) axle shaft, disconnect
electrical connector and vacuum hoses at vacuum shift motor. Remove
bolts, vacuum shift motor and gasket. Carefully pull axle shaft from
axle housing and collar on intermediate axle shaft.
Installation
1) Install NEW oil seal on axle shaft with seal lip facing
toward splines on differential end of axle shaft. Coat seal lip with
wheel bearing grease.
2) Install right axle shaft into axle housing. Ensure axle
shaft engages with side gears in differential.
3) To install left axle shaft, ensure collar is engaged with
splines on intermediate axle shaft. Install left axle shaft into axle
housing. Ensure axle shaft engages with splines on collar. Install
vacuum shift motor, ensuring fork on vacuum shift motor engages groove
on collar. Install and tighten bolts to specification. See TORQUE
SPECIFICATIONS table.
4) To complete installation, reverse removal procedure. Apply
silicone rubber sealant to edge of grease cap before installing.
Tighten bolts/nuts to specification. See TORQUE SPECIFICATIONS table.
DRIVE SHAFT
Removal
1) Raise and support vehicle. Ensure transmission and
transfer selector levers case are in Neutral. Reference mark drive
shaft and pinion flange for reassembly reference.
2) Remove bolts and "U" joint straps at pinion flange. Remove
center carrier bearing bolts (if equipped). Remove drive shaft.
CAUTION: The "U" joint components are not serviceable. Replace
complete assembly. 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 and
pinion flange on differential for reassembly. Remove bolts and "U"
joint straps at pinion flange on differential. Disconnect drive shaft
from differential, and support it 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 (C-3281)\
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.
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 table.
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
table. 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) Raise and support vehicle. Remove front wheels. Reference
mark drive shaft to pinion flange for reassembly. Remove bolts and "U"
joint straps at pinion flange. Remove drive shaft, and support aside.
Remove brake calipers, and support aside with wire. DO NOT allow
calipers to hang from brake hoses.
2) Disconnect ABS sensor harness connectors (if equipped).
Disconnect drag link and tie rod from steering knuckles. Disconnect
shock absorber from axle housing. Disconnect stabilizer bar links at
spring brackets.
3) Disconnect electrical connector and vacuum hoses at vacuum
shift motor. Support axle housing assembly with floor jack. Remove
bolts from upper and lower suspension arms. Lower axle housing
assembly from vehicle and remove.
Installation
To install, reverse removal procedure. Ensure reference marks
on drive shaft and pinion flange align. Tighten suspension arms with
vehicle at normal operating height. Tighten bolt/nuts to
specification. See TORQUE SPECIFICATIONS table. Check axle fluid level
(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.
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
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