Dodge Ram Truck 1500-2500-3500. Manual — part 120

DIAGNOSTIC CHART

Condition

Possible Causes

Correction

Wheel Noise

1. Wheel loose.

1. Tighten loose nuts.

2. Faulty, brinelled wheel bearing.

2. Replace bearing.

Axle Shaft Noise

1. Misaligned axle tube.

1. Inspect axle tube alignment.
Correct as necessary.

2. Bent or sprung axle shaft.

2. Inspect and correct as necessary.

Axle Shaft Broke

1. Misaligned axle tube.

1. Replace the broken shaft after
correcting tube mis-alignment.

2 Vehicle overloaded.

2. Replace broken shaft and avoid
excessive weight on vehicle.

3. Erratic clutch operation.

3. Replace broken shaft and avoid
or correct erratic clutch operation.

4. Grabbing clutch.

4. Replace broken shaft and inspect
and repair clutch as necessary.

Differential Cracked

1. Improper adjustment of the
differential bearings.

1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.

2. Excessive ring gear backlash.

2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.

3. Vehicle overloaded.

3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.

4. Erratic clutch operation.

4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.

Differential Gears Scored

1. Insufficient lubrication.

1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.

2. Improper grade of lubricant.

2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.

3. Excessive spinning of one
wheel/tire.

3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.

Loss Of Lubricant

1. Lubricant level too high.

1. Drain lubricant to the correct
level.

2. Worn axle shaft seals.

2. Replace seals.

3. Cracked differential housing.

3. Repair as necessary.

4. Worn pinion seal.

4. Replace seal.

5. Worn/scored yoke.

5. Replace yoke and seal.

6. Axle cover not properly sealed.

6. Remove, clean, and re-seal
cover.

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REAR AXLE - 11 1/2 AA

DR/DH

Condition

Possible Causes

Correction

Axle Overheating

1. Lubricant level low.

1. Fill differential to correct level.

2. Improper grade of lubricant.

2. Fill differential with the correct
fluid type and quantity.

3. Bearing pre-loads too high.

3. Re-adjust bearing pre-loads.

4. Insufficient ring gear backlash.

4. Re-adjust ring gear backlash.

Gear Teeth Broke

1. Overloading.

1. Replace gears. Examine other
gears and bearings for possible
damage.

2. Erratic clutch operation.

2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.

3. Ice-spotted pavement.

3. Replace gears and examine
remaining parts for damage.

4. Improper adjustments.

4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.

Axle Noise

1. Insufficient lubricant.

1. Fill differential with the correct
fluid type and quantity.

2. Improper ring gear and pinion
adjustment.

2. Check ring gear and pinion
contact pattern. Adjust backlash or
pinion depth.

3. Unmatched ring gear and pinion.

3. Replace gears with a matched
ring gear and pinion.

4. Worn teeth on ring gear and/or
pinion.

4. Replace ring gear and pinion.

5. Loose pinion bearings.

5. Adjust pinion bearing pre-load.

6. Loose differential bearings.

6. Adjust differential bearing
pre-load.

7. Mis-aligned or sprung ring gear.

7. Measure ring gear run-out.
Replace components as necessary.

8. Loose differential bearing cap
bolts.

8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.

9. Housing not machined properly.

9. Replace housing.

DR/DH

REAR AXLE - 11 1/2 AA

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REMOVAL

1. With vehicle in neutral, position vehicle on hoist.

2. Position a lift under axle and secure lift to the axle.

3. Remove all brake components.

4. Mark propeller shaft and companion flange for

installation alignment reference.

5. Remove propeller shaft.

6. Remove axle vent hose.

7. Remove shock absorbers (3) from axle (2).

8. Remove U-bolts (4) from axle.

9. Remove axle from the vehicle.

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REAR AXLE - 11 1/2 AA

DR/DH

INSTALLATION

1. Raise axle with lift and align to the leaf spring (1)

centering bolts.

2. Install axle U-bolts (5) and tighten to 149 N·m (110

ft. lbs.).

3. Install shock absorbers to axle and tighten to spec-

ification.

4. Install all brake components.

5. Install propeller shaft with reference marks aligned

and tighten to specification.

6. Install axle vent hose.

7. Fill differential to specifications.

8. Remove lift from axle and lower the vehicle.

ADJUSTMENTS

PINION DEPTH MEASUREMENT

Ring and pinion gears are supplied as matched sets.
Compensation for pinion depth variance is achieved
with a select shim, located between the rear pinion
bearing and pinion gear head.

Measurements are taken with pinion bearing cups and
pinion bearings installed in the housing. Take mea-
surements with Pinion Gauge Set and Dial Indicator
C-3339 (1).

1. Assemble Pinion Height Block 6739 (3), Pinion

Block 8897 (6) and rear pinion bearing onto Screw
6741(5).

DR/DH

REAR AXLE - 11 1/2 AA

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