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 \
\
\
\
\
\
\
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
\
\
\
\
\
\
\
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) \
\
\
\
\
\
\
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.
\
\
\
\
\
\
\
Stud loose in
taper hole ............. A ........... (7) Require repair or
replacement.
Taper hole elongated .... A ........ ( 8) Require replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ........ ( 7) Require replacement.
Wear exceeds
manufacturer's
specifications .......... B ............ Require replacement.
( 1) - If greaseable, grease joint. If problem persists or
joint is non-greaseable, require replacement.
( 2) - Cracked grease boot will allow contaminants to enter
the joint and will accelerate wear.
( 3) - Lack of grease boot will allow contaminants to enter
the joint and will accelerate wear.
( 4) - Torn grease boot will allow contaminants to enter the
joint and will accelerate wear.
( 5) - If manufacturer's procedures for inspection exist, use
those procedures; otherwise, use an approved inspection
method such as the dry park check.
CAUTION: DO NOT use pliers or pry bar to check ball and
socket movement. Use only moderate hand pressure.
( 6) - Excessive looseness is defined as being significant
enough to affect vehicle handling or structural
integrity.
( 7) - Check for damaged taper hole.
( 8) - Check for damaged stud.
\
\
\
\
\
\
\
SHOCK ABSORBERS, STRUT CARTRIDGES AND STRUT ASSEMBLIES
You are not required to replace shocks or struts in axle
sets. However, when replacing a shock or strut due to the conditions
that follow, you may suggest replacement of the other shock or strut
on the same axle for improved performance and preventive maintenance.
* Part is close to the end of its useful life
* To extend tire life
* To balance ride and handling
* To improve stopping distance
When replacing steering and/or suspension components which
may affect an alignment angle, you are required to check and adjust
alignment as needed. Refer to the OEM specifications.
Under no circumstances should a technician bend struts or
strut housings.
A vehicle's load-carrying and handling abilities are limited
by its suspension, tires, brakes, and driveline. Installing coil over
shocks or any other load assist device does not increase the vehicle's
load capacity. See the vehicle owner's manual for more details.
NOTE: If vehicle is equipped with original equipment coil over
shocks, apply the conditions for coil springs from the
SPRINGS - COIL, LEAF AND TORSION BAR section of the
STEERING AND SUSPENSION guidelines. If the vehicle is
equipped with add-on coil over shocks, you may suggest
replacing the shocks with standard shocks for any spring-
related condition.
SHOCK ABSORBER, STRUT CARTRIDGE AND STRUT ASSEMBLY INSPECTION
\
\
\
\
\
\
\
be caused by
faulty alignment ....... A ............. Require alignment.
Part has been changed,
affecting alignment .... A ....... Require alignment check.
Pull, shown to be caused
by faulty alignment .... A ............. Require alignment.
Steering wheel
off-center ............. 2 ............. Suggest alignment.
Tire wear, shown
to be caused by
faulty alignment ....... A ............. Require alignment.
Wander, shown
to be caused by
faulty alignment ....... A ............. Require alignment.
\
\
\
\
\
\
\
WHEELS AND TIRES
TIRES
These guidelines do not apply to split rims. Some vehicle
manufacturers restrict replacement of tires to specific brands, types,
or sizes.
WARNING: High pressure temporary compact spare tires should not be
used with any other rims or wheels, nor should standard
tires, snow tires, wheel covers, or trim rings be used
with high pressure compact spare rims or wheels.
Attempting to mount a tire of one diameter on a wheel of
a different diameter or flange type may result in serious
injury or death.
WARNING: Only specially trained persons should dismount or mount
tires. Explosions of tire and wheel assembly can result
from improper mounting, possibly causing serious injury
or death.
WARNING: Consult the vehicle owner's manual or vehicle placard for
correct size, speed rating, designation, and cold
inflation pressure of the original tires. DO NOT exceed
the maximum load or inflation capacity of the tire
specified by the Tire and Rim Association
WARNING: When replacing tires, it is suggested that the
replacement tires match or exceed the OEM speed rating
designation. If tires of different speed rating
designations are mixed on the same vehicle, the tires may
vary in handling characteristics. DO NOT mix different
speed rating designations on the same axle.
WARNING: DO NOT mix radials with non-radial tires on the same
axle, as this may affect vehicle handling and stability.
If radial tires and bias or bias-belted ply tires are
mixed on the same vehicle, the radials must be on the
rear. High-pressure temporary compact spare tires are
exempt from this rule.
WARNING: DO NOT mix size or type (all season, performance, mud and
snow) of tires on the same axle.
TIRE INSPECTION
\
\
\
\
\
\
\
Load capacity less than
OEM specifications ..... B ............ Require replacement.
Offset mismatched
on same axle ........... B ............ Require replacement.
Rivets leaking .......... A ............ Require replacement.
Run-out beyond
OEM specs .............. B ............ Require replacement.
Stud holes elongated .... A ........ (2) Require replacement.
Welded or brazed
repair ................. 2 ............ Suggest replacement.
Welds leaking ........... A ............ Require replacement.
Wheel centering (pilot)
hole incorrect ......... B ............ Require replacement.
( 1) - CAUTION: DO NOT attempt to correct a bent rim.
( 2) - Inspect wheel attaching hardware for damage.
\
\
\
\
\
\
\
Stud loose in
taper hole ............. A ........... (7) Require repair or
replacement.
Taper hole elongated .... A ........ ( 8) Require replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ........ ( 7) Require replacement.
Wear exceeds
manufacturer's
specifications .......... B ............ Require replacement.
( 1) - If greaseable, grease joint. If problem persists or
joint is non-greaseable, require replacement.
( 2) - Cracked grease boot will allow contaminants to enter
the joint and will accelerate wear.
( 3) - Lack of grease boot will allow contaminants to enter
the joint and will accelerate wear.
( 4) - Torn grease boot will allow contaminants to enter the
joint and will accelerate wear.
( 5) - If manufacturer's procedures for inspection exist, use
those procedures; otherwise, use an approved inspection
method such as the dry park check.
CAUTION: DO NOT use pliers or pry bar to check ball and
socket movement. Use only moderate hand pressure.
( 6) - Excessive looseness is defined as being significant
enough to affect vehicle handling or structural
integrity.
( 7) - Check for damaged taper hole.
( 8) - Check for damaged stud.
\
\
\
\
\
\
\
SHOCK ABSORBERS, STRUT CARTRIDGES AND STRUT ASSEMBLIES
You are not required to replace shocks or struts in axle
sets. However, when replacing a shock or strut due to the conditions
that follow, you may suggest replacement of the other shock or strut
on the same axle for improved performance and preventive maintenance.
* Part is close to the end of its useful life
* To extend tire life
* To balance ride and handling
* To improve stopping distance
When replacing steering and/or suspension components which
may affect an alignment angle, you are required to check and adjust
alignment as needed. Refer to the OEM specifications.
Under no circumstances should a technician bend struts or
strut housings.
A vehicle's load-carrying and handling abilities are limited
by its suspension, tires, brakes, and driveline. Installing coil over
shocks or any other load assist device does not increase the vehicle's
load capacity. See the vehicle owner's manual for more details.
NOTE: If vehicle is equipped with original equipment coil over
shocks, apply the conditions for coil springs from the
SPRINGS - COIL, LEAF AND TORSION BAR section of the
STEERING AND SUSPENSION guidelines. If the vehicle is
equipped with add-on coil over shocks, you may suggest
replacing the shocks with standard shocks for any spring-
related condition.
SHOCK ABSORBER, STRUT CARTRIDGE AND STRUT ASSEMBLY INSPECTION
\
\
\
\
\
\
\
be caused by
faulty alignment ....... A ............. Require alignment.
Part has been changed,
affecting alignment .... A ....... Require alignment check.
Pull, shown to be caused
by faulty alignment .... A ............. Require alignment.
Steering wheel
off-center ............. 2 ............. Suggest alignment.
Tire wear, shown
to be caused by
faulty alignment ....... A ............. Require alignment.
Wander, shown
to be caused by
faulty alignment ....... A ............. Require alignment.
\
\
\
\
\
\
\
WHEELS AND TIRES
TIRES
These guidelines do not apply to split rims. Some vehicle
manufacturers restrict replacement of tires to specific brands, types,
or sizes.
WARNING: High pressure temporary compact spare tires should not be
used with any other rims or wheels, nor should standard
tires, snow tires, wheel covers, or trim rings be used
with high pressure compact spare rims or wheels.
Attempting to mount a tire of one diameter on a wheel of
a different diameter or flange type may result in serious
injury or death.
WARNING: Only specially trained persons should dismount or mount
tires. Explosions of tire and wheel assembly can result
from improper mounting, possibly causing serious injury
or death.
WARNING: Consult the vehicle owner's manual or vehicle placard for
correct size, speed rating, designation, and cold
inflation pressure of the original tires. DO NOT exceed
the maximum load or inflation capacity of the tire
specified by the Tire and Rim Association
WARNING: When replacing tires, it is suggested that the
replacement tires match or exceed the OEM speed rating
designation. If tires of different speed rating
designations are mixed on the same vehicle, the tires may
vary in handling characteristics. DO NOT mix different
speed rating designations on the same axle.
WARNING: DO NOT mix radials with non-radial tires on the same
axle, as this may affect vehicle handling and stability.
If radial tires and bias or bias-belted ply tires are
mixed on the same vehicle, the radials must be on the
rear. High-pressure temporary compact spare tires are
exempt from this rule.
WARNING: DO NOT mix size or type (all season, performance, mud and
snow) of tires on the same axle.
TIRE INSPECTION
\
\
\
\
\
\
\
Load capacity less than
OEM specifications ..... B ............ Require replacement.
Offset mismatched
on same axle ........... B ............ Require replacement.
Rivets leaking .......... A ............ Require replacement.
Run-out beyond
OEM specs .............. B ............ Require replacement.
Stud holes elongated .... A ........ (2) Require replacement.
Welded or brazed
repair ................. 2 ............ Suggest replacement.
Welds leaking ........... A ............ Require replacement.
Wheel centering (pilot)
hole incorrect ......... B ............ Require replacement.
( 1) - CAUTION: DO NOT attempt to correct a bent rim.
( 2) - Inspect wheel attaching hardware for damage.
\
\
\
\
\
\
\