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 front bearing outer race using tool Nos. MB990932 and MB990938, or equivalents, and rear bearing outer race using tool Nos. MB990935 and MB990938, or equivalents.
3. Adjust pinion height as follows:

Fig. 29 Drive Pinion Front & Rear Bearing Inner Race Installation:

a. Apply a thin film of suitable multi-purpose grease to mating face of tool washer, Fig. 29, then install tools and drive pinion front and rear bearing inner races on gear carrier.
b. Gradually tighten nut on tool until standard drive pinion turning torque value shown in Fig. 27 is obtained.

Fig. 30 Side Bearing Tool Orientation:

c. Thoroughly clean side bearing seat, then install tools, Fig. 30, and bearing cap. Ensure tool cutout sections are positioned as shown in Fig. 30 and tool contacts side bearing seat.
d. Use a suitable feeler gauge to measure clearance (dimension A) between tools, Fig. 30, then remove tools.

Fig. 31 Side Bearing Clearance Measurements:

e. Use a suitable micrometer to measure tool dimensions B and C, Fig. 31.

Fig. 32 Bearing Cap Clearance Measurement:

f. Install bearing cap, then use a suitable cylinder gauge and micrometer to measure inside diameter of bearing bore (dimension D), Fig. 32.
g. Calculate drive pinion rear shim thickness. Thickness is equal to dimension A + B + C - 1/2D - 3.39 inches.
h. Select a shim that is as close to calculated thickness as possible, then fit shim on drive pinion and press fit rear bearing inner race using tool No. MB990728, 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 137 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.
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.