MAINTENANCE SCHEDULES
LIGHT DUTY ENGINE (1500 AND 2500
MODELS EXCEPT 8.0L) MAINTENANCE
SCHEDULES
There are two maintenance schedules that show
proper service for the vehicle.
First is ScheduleªAº. It lists all the scheduled
maintenance to be performed under ªnormalº operat-
ing conditions.
Second is ScheduleªBºIt is a schedule for vehicles
that are operated under the conditions listed at the
beginning of that schedule.
Use the schedule that best describes the driving
conditions.
Where time and mileage are listed, follow the
interval that occurs first.
At Each Stop For Fuel
²Check engine oil level and add as required.
²Check windshield washer solvent and add as
required.
²Clean windshield and wiper blades as required.
Once A Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, brake
master cylinder, power steering, and transmission
and add as needed.
²Check all lights and all other electrical items for
correct operation.
²Inspect and clean wiper blades. Replace if
required.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses.
²Adjust rear brake shoe to drum clearance.
²Rotate the tires at each oil change interval
shown on schedule ªAº (7,500 Miles) or every other
interval shown on schedule ªBº (6,000 Miles).
²Check engine coolant level, hoses, and clamps.
²Lubricate steering linkage.
EMISSION CONTROL SYSTEM MAINTENANCE
The scheduled emission maintenance listed inbold
typeon the Maintenance Schedules, must be done at
the mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operatingconditions such as dusty areas and very short trip
driving.
FLUID FILL LOCATIONS AND LUBRICATION
POINTS
The fluid check/fill locations and lubrication points
are located in each applicable group.
LIGHT DUTY SCHEDULE ªAº
7,500 Miles (12 000 km) or at 6 months
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Check manual transmission fluid level.
²Inspect exhaust system.
15,000 Miles (24 000 km) or at 12 months
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Check manual transmission fluid level.
²Inspect exhaust system.
22,500 Miles (36 000 km) or at 18 months
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Inspect brake linings.
²Inspect front wheel bearings. Clean and repack,
if required (4x2).
²Lubricate the steering linkages.
²Lubricate non permanently sealed ball joints.
²Check manual transmission fluid level.
²Inspect exhaust system.
30,000 Miles (48 000 km) or at 24 months
²Replace engine air cleaner element.
²Replace spark plugs.
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Inspect manual transmission fluid level.
²Inspect exhaust system.
37,500 Miles (60 000 km) or at 30 months
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
BR/BELUBRICATION & MAINTENANCE 0 - 7
²Change front axle fluid (4x4).
²Inspect exhaust system.
111,000 Miles (178 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Flush and replace engine coolant.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Check manual transmission fluid level.
²Inspect exhaust system.
114,000 Miles (182 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Check manual transmission fluid level.
²Inspect exhaust system.
117,000 Miles (187 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Lubricate the steering linkages.
²Check manual transmission fluid level.
²Inspect exhaust system.
120,000 Miles (192 000 km)
²Replace engine air cleaner element.
²Replace ignition cables.
²
Inspect PCV valve and replace as necessary.*
²Replace spark plugs.
²Inspect auto tension drive belt and replace if
required.**
²Change engine oil.
²Replace engine oil filter.
²Inspect engine coolant level, hoses, and clamps.
²Inspect brake hoses.
²Inspect brake linings.
²Lubricate the steering linkages.
²Change automatic transmission fluid, filter and
adjust the bands.
²Check manual transmission fluid level.
²Change rear axle fluid.
²Change front axle fluid (4x4).
²Inspect exhaust system.
*This maintenance is recommended by Daimler-
Chrysler to the customer but it is not required to
maintain warranty on the PCV valve.
**This maintenance is not required if the belt was
previously replaced.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
DESCRIPTION - MEDIUM DUTY TRUCK
MAINTENANCE SCHEDULE (8.0L 2500 & 3500
MODELS Ð CALIFORNIA ONLY)
There are two maintenance schedules that show
proper service based on the conditions that the vehi-
cle is subjected to. Use the schedule that best
describes these conditions.
ScheduleªAº, lists all the scheduled maintenance
to be performed under normal operating conditions
for Medium Duty vehicles.
ScheduleªBº, lists maintenance recommended for
Medium Duty vehicles operated under the conditions
listed at the beginning of that schedule.
²Where the time and mileage are listed, follow
the interval that occurs first.
At Each Stop For Fuel
²Check engine oil level and add as required.
²Check windshield washer solvent and add as
required.
²Clean windshield and wiper blades as required.
Once A Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, brake
master cylinder, power steering, and transmission
and add as needed.
²Check all lights and all other electrical items for
correct operation.
²
Inspect and clean wiper blades. Replace if required.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses.
²Adjust rear brakes.
²Rotate the tires at each oil change interval
shown on schedule ªAº (6,000 Miles) or every other
interval shown on schedule ªBº (6,000 Miles)
²Check engine coolant level, hoses and clamps.
²Lubricate steering linkage.
EMISSION CONTROL SYSTEM MAINTENANCE
The scheduled emission maintenance listed inbold
typeon the Maintenance Schedules, must be done at
the mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
BR/BELUBRICATION & MAINTENANCE 0 - 13
MAINTENANCE SCHEDULES (Continued)
²Inspect brake linings.
³Off-the-highway operation, trailer towing snow
plowing, prolonged operation with heavy loading,
especially in hot weather require the more frequent
transmission service indicated with an ³ in Schedule
ªBº. Perform these services if the vehicle is usually
operated under these conditions.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
DESCRIPTION - HEAVY DUTY ENGINE
(FEDERAL ONLY ± 2500 8.0L HD AND 3500
5.9L& 8.0L MODELS) MAINTENANCE
SCHEDULES
There are two maintenance schedules that show
proper service based on the conditions that the vehi-
cle is subjected to. Use the schedule that best
describes these conditions.
ScheduleªAº, lists all the scheduled maintenance
to be performed under normal operating conditions
for Heavy Duty vehicles.
ScheduleªBº, lists maintenance recommended for
Heavy Duty vehicles operated under the conditions
listed at the beginning of that schedule.
²Where time and mileage are listed, follow the
interval that occurs first.
At Each Stop For Fuel
²Check engine oil level, add as required.
²Check windshield washer solvent and add if
required.
²Clean windshield and wiper blades as required.
Once A Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, power
steering and transmission and add as needed.
²Check all lights and all other electrical items for
correct operation.
²Inspect and clean wiper blades. Replace if
required.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses.
²Adjust rear brakes.
²Rotate the tires at each oil change interval
shown on schedule ªAº (6,000 Miles) or every other
interval shown on schedule ªBº (6,000 Miles).
²Check engine coolant level, hoses, and clamps.
²Lubricate steering linkage.
EMISSION CONTROL SYSTEM MAINTENANCE
The scheduled emission maintenance listed inbold
typeon the Maintenance Schedules, must be done at
the mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
FLUID FILL LOCATIONS AND LUBRICATION
POINTS
The fluid fill/check locations and lubrication points
are located in each applicable group.
HEAVY DUTY SCHEDULE ªAº
6,000 miles (10 000 km) or at 6 months
²Change engine oil.
²Replace engine oil filter.
12,000 Miles (19 000 km) or at 12 months
²Change engine oil.
²Replace engine oil filter.
²Inspect engine air cleaner element, replace
as necessary (8.0L only).
18,000 Miles (29 000 km) or at 18 months
²Change engine oil.
²Replace engine oil filter.
²Inspect brake linings
²Inspect front wheel bearings. Clean and repack,
if required (4x4).
24,000 Miles (38 000 km) or at 24 months
²Change engine oil.
²Replace engine oil filter.
²Replace engine air cleaner element and air
pump filter.
²Clean and lubricate crankcase inlet air filter
(5.9L).
²Drain and refill automatic transmission fluid.
Replace filter and adjust bands.
²Inspect front wheel bearings. Clean and repack,
if required (4x2).
30,000 Miles (48 000 km) or at 30 months
²Change engine oil.
²Replace engine oil filter.
²Replace spark plugs.
36,000 Miles (58 000 km) or at 36 months
²Change engine oil.
²Replace engine oil filter.
BR/BELUBRICATION & MAINTENANCE 0 - 17
MAINTENANCE SCHEDULES (Continued)
99,000 Miles (156 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x2).
102,000 Miles (163 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x4).
105,000 Miles (168 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
108,000 Miles (173 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect engine air cleaner element and air
pump filter, replace as necessary.
²Drain and refill automatic transmission fluid.
Replace filter and adjust bands.³
²Drain and refill transfer case fluid (4x4).
²Change rear axle fluid.
²Change front axle fluid (4x4).
²Inspect brake linings.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) since last change.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x4).
²Inspect front wheel bearings (4x2).
*Requires Service Reminder Indicator Light. If so
equipped, these parts are to be replaced at the indi-
cated mileage or when the service reminder indicator
light remains on continuously with the key in the
ªONº position, whichever occurs first.
³Off-the-highway operation, trailer towing, snow
plowing, prolonged operation with heavy loading,
especially in hot weather require the more frequent
transmission service indicated witha³inSchedule
ªBº. Perform these services if you usually operate
your Ram Truck under these conditions.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
DESCRIPTION - MAINTENANCE SCHEDULES
Ð 24±VALVE CUMMINS TURBO DIESEL
There are two maintenance schedules that show
proper service for the vehicle.First is ScheduleªA.ºIt lists all the scheduled
maintenance to be performed under ªnormalº operat-
ing conditions.
Second is ScheduleªB.ºIt is a schedule for vehicles
that are operated under the conditions listed at the
beginning of that schedule.
Use the schedule that best describes the driving
conditions.
Where time and mileage are listed, follow the
interval that occurs first.
At Each Stop For Fuel
²Check engine oil level and add as required.
²Check windshield washer solvent and add if
required.
²Clean windshield and wiper blades as required.
²Drain water from fuel filter.
Once A Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, brake
master cylinder, power steering, and transmission.
Add fluid as required.
²Check all lights and all other electrical items for
correct operation.
²Check Filter Mindery. Replace air cleaner
element if necessary.
²Inspect and clean wiper blades. Replace if
required.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses.
²Adjust rear brakes.
²Rotate the tires at each oil change interval
shown at 7, 5000 miles (12 000 km) on schedule ªAº
or every other interval shown at 7,500 miles (12 000
km) on schedule ªBº.
²Check engine coolant level, hoses, and clamps.
²Lubricate steering linkage.
²Drain crankcase breather canister (if equipped).
EMISSION CONTROL SYSTEM MAINTENANCE
The scheduled emission maintenance listed inbold
typeon the Maintenance Schedules, must be done at
the mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
0 - 22 LUBRICATION & MAINTENANCEBR/BE
MAINTENANCE SCHEDULES (Continued)
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
BR/BEREAR AXLE - 9 1/4 3 - 81
REAR AXLE - 9 1/4 (Continued)
of traction, the wheel with the least traction may
spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
BR/BEREAR AXLE - 248RBI 3 - 111
REAR AXLE - 248RBI (Continued)
ally utilizes a ramping action supplied by the cross
shafts to increase the force applied to the clutch
packs to increase the torque supplied to the non-slip-
ping wheel. Powr-lokydifferentials resist wheel spin
on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided continuously until both wheels loose traction. If
both wheels slip due to unequal traction, operation is
normal. In extreme cases of differences of traction,
the wheel with the least traction may spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
3 - 142 REAR AXLE - 267RBIBR/BE
REAR AXLE - 267RBI (Continued)
on bumpy roads and provide more pulling power when
one wheel looses traction. Pulling power is provided
continuously until both wheels loose traction. If both
wheels slip due to unequal traction, Trac-lokyopera-
tion is normal. In extreme cases of differences of trac-
tion, the wheel with the least traction may spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changeswhen the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
BR/BEREAR AXLE - 286RBI 3 - 171
REAR AXLE - 286RBI (Continued)