Assembly

Fig. 22 Rear Differential Assembly:

Fig. 23 Rear Differential Assembly:

Assemble differential carrier in numbered sequence shown in Figs. 22 and 23, noting the following:

1. Apply grease to oil seal lip; then, using oil seal installer tool No. MB991115 and handle tool No. MB990938-01, or equivalents, press fit oil seal until it is flush with end of gear carrier.
2. Press fit drive pinion rear and front bearing outer races onto gear carrier using handle tool and bearing and oil seal installer set tool No. MB990925, or equivalent. Use care not to press in outer race at an angle.
3. Adjust pinion height as follows:

Fig. 25 Pinion Height Adjustment:

Fig. 26 Pinion Height Adjustment:

a. Install special tools as shown in Figs. 25 and 26.

Fig. 27 Pinion Turning Torque:

Fig. 28 Pinion Turning Torque:

b. Tighten handle of tool until the standard drive pinion turning torque value shown in Figs. 27 and 28 and is obtained.
c. Measure drive pinion turning torque without oil seal installed.
d. Position gauge tube tool No. MB990392-01, or equivalent, in side bearing seat of gear carrier, then select a drive pinion rear shim of thickness which corresponds to gap between special tools.
e. Install selected shim on drive pinion and press fit rear bearing inner race using bearing installer tool No. MT215013, or equivalent.
4. Adjust drive pinion preload as follows:
a. Install drive pinion front shim(s) between pinion spacer and pinion front bearing inner race.
b. Torque companion flange to 116-159 ft. lbs., using end yoke holder tool to prevent yoke rotation. Do not install oil seal.
c. Ensure drive pinion turning torque is as shown in Figs. 27 and 28.
d. If drive pinion turning torque is not within specified range, adjust by replacing drive pinion front shims(s) or drive pinion spacer.
e. Remove companion flange and drive pinion.
f. Install oil seal using suitable oil seal installation tool.
g. Install drive pinion and companion flange aligning marks made during disassemble then tighten companion flange self-locking nut to specification.
h. Measure pinion turning torque with oil seal installed and ensure turning torque is no more than one inch lb. greater than what is shown in Figs. 27 and 28.
5. On models with conventional differential, adjust differential gear backlash as follows:
a. Assemble side gears and spacers, pinion gears and washers into differential case.
b. Temporarily install pinion shaft.
c. While locking side gear with wedge, measure differential gear backlash with a dial indicator on pinion gear. The measurement should be made for both pinion gears individually.
d. If differential gear backlash exceeds 0.008 inch, adjust backlash by installing thicker side gear spacers.
e. Measure differential gear backlash again and confirm it is within the specification.
f. After adjustment, ensure backlash is less than limit and differential gear rotates smoothly.
g. When adjustment is impossible, replace side gear pinion gears as a set.
h. Align pinion shaft lockpin hole with differential case and install lockpin.
i. Stake lockpin at two points.
6. Clean drive gear attaching bolts.
7. Use a 10 mmx 1.25 tap to remove adhesive from threaded holes of drive gear.
8. Install drive gear onto differential case aligning marks made during disassemble. Tighten bolts in a diagonal sequence.
9. Press side bearing inner races onto differential case.
10. Adjust final drive gear backlash as follows:
a. Install side bearing spacers, which are thinner than those removed, and mount the differential case assembly into the gear carrier.
b. Push differential case to one side and measure clearance between gear carrier and side bearing.
c. Measure thickness of side bearing spacers on one side, select two pairs of spacers which correspond to thickness plus one half of clearance plus 0.002 inch. Install one pair each to drive pinion side and drive gear side.
d. Install side bearing spacers and differential case assembly into gear carrier.
e. Tap side bearing spacers with a suitable brass bar to fit them to side bearing outer race.
f. Align marks made during disassembling then tighten bearing cap.
g. With drive pinion locked in place, measure final drive gear backlash.

Fig. 33 Gear Backlash Adjustment:

h. If backlash is not 0.004-0.006 inch, change bearing spacers as shown in Fig. 33 to obtain correct backlash.
i. Check tooth contact as outlined under "Inspection Before Disassemble".
j. Measure drive gear runout at shoulder on reverse side of drive gear.
k. If runout exceeds 0.002 inch, reinstall by changing phase of drive gear and differential case and measure again.