Dodge Ram Truck 1500-2500-3500. Manual — part 131

Compensation for pinion depth variance is achieved
with a select shim (1). The shims are located between
the rear pinion bearing and pinion gear head.

If installing a new gear, note the depth variance num-
ber of the original and replacement pinion. Add or sub-
tract this number from the original depth shim/oil
slinger to compensate for the difference in the depth
variances. The numbers represent thousands of an
inch deviation from the standard. If the number is neg-
ative, add that value to the required thickness of the
depth shims. If the number is positive, subtract that
value from the thickness of the depth shim.

Pinion Gear Depth Variance Chart: Note where Old and New Pinion Marking columns intersect. Intersecting figure
represents plus or minus the amount needed.

PINION GEAR DEPTH VARIANCE

Original Pinion

Gear Depth

Variance

Replacement Pinion Gear Depth Variance

2

4

2

3

2

2

2

1

0

+1

+2

+3

+4

+4

+0.008

+0.007

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

0

+3

+0.007

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

0

2

0.001

+2

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

0

2

0.001

2

0.002

+1

+0.005

+0.004

+0.003

+0.002

+0.001

0

2

0.001

2

0.002

2

0.003

0

+0.004

+0.003

+0.002

+0.001

0

2

0.001

2

0.002

2

0.003

2

0.004

2

1

+0.003

+0.002

+0.001

0

2

0.001

2

0.002

2

0.003

2

0.004

2

0.005

2

2

+0.002

+0.001

0

2

0.001

2

0.002

2

0.003

2

0.004

2

0.005

2

0.006

2

3

+0.001

0

2

0.001

2

0.002

2

0.003

2

0.004

2

0.005

2

0.006

2

0.007

2

4

0

2

0.001

2

0.002

2

0.003

2

0.004

2

0.005

2

0.006

2

0.007

2

0.008

3 - 356

REAR AXLE - 248RBI

DR/DH

PINION DEPTH MEASUREMENT

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 6736 (6) and rear pinion bearing onto Screw
6741(5).

2. Insert assembled pinion block (1), pinion height

block (2), rear bearing and screw into the housing
through pinion bearing cups.

3. Install front pinion bearing and Cone-nut 6740 onto

the screw. Tighten cone-nut until Torque To Rotate
the screw is 2.2 N·m (20 in. lbs.).

DR/DH

REAR AXLE - 248RBI

3 - 357

4. Place Arbor Disc 6732 (1) on Arbor D-115-3 (3) in

position in the housing side bearing cradles.

NOTE: Arbor Discs 6732 (1) has different step
diameters to fit other axles. Choose proper step
for axle being serviced.

5. Install differential bearing caps on arbor discs and

snug the bearing cap bolts. Then cross tighten cap
bolts to 108 N·m (80 ft. lbs.).

6. Assemble Dial Indicator C-3339 (3) into Scooter

Block D-115-2 (2) and secure set screw.

7. Position Scooter Block/Dial Indicator flush on the

pinion height block. Hold scooter block and zero
the dial indicator.

8. Slowly slide the scooter block across the pinion

height block over to the arbor. Move the scooter
block till dial indicator crests the arbor (1), then
record the highest reading.

9. Select a shim equal to the dial indicator reading

plus the pinion depth variance number etched in
the face of the pinion. For example, if the depth
variance is –2, add +0.002 in. to the dial indicator
reading.

3 - 358

REAR AXLE - 248RBI

DR/DH

DIFFERENTIAL SIDE BEARING PRELOAD

Differential side bearing preload and gear backlash is
achieved by selective shims (2) positioned behind the
differential side bearing cones. The proper shim thick-
ness can be determined using slip-fit Dummy Bearings
D-343 in place of the differential side bearings and a
Dial Indicator C-3339. Before measuring differential
bearing preload and gear backlash, measure pinion
gear depth and prepare pinion for installation. Pinion
gear depth is essential to establishing gear backlash
and tooth contact patterns. After measuring shim thick-
ness to take up differential side play, install pinion and
measure gear backlash shim thickness. Overall shim
thickness is the dial indicator reading and preload
specification added together. The gear backlash mea-
surement determines the shim thickness used on the
ring gear side of the differential case. Subtract gear
backlash shim thickness from overall shim thickness
to determine shim thickness for pinion gear side of the
differential. Differential shim measurements are per-
formed with spreader W-129-B removed.

SHIM SELECTION

NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.

1. Remove differential side bearings from differential

case.

2. Remove factory installed shims from differential

case.

3. Install ring gear on differential case and tighten

bolts to specification.

4. Install dummy side bearings D-343 on differential

case.

5. Install differential case (3) in the housing (2).

6. Install the marked bearing caps (1) in their correct

positions and snug the bolts.

DR/DH

REAR AXLE - 248RBI

3 - 359