Drive Pinion

1. Press drive front and rear bearing outer races into gear carrier using tools MB990934, MB990936 and MB990938 or equivalent.
2. Adjust drive pinion height as follows:
a. Install tool MB990819 and the drive pinion bearings into gear carrier. Apply a thin coat of suitable grease to washer on tool.
b. Gradually tighten nut on tool until drive pinion preload is 6-9 inch lbs. on 1983-85 models or 3.5-4.3 inch lbs. on 1986-87 models.

Fig. 6 Measuring drive pinion height:

c. Position cylinder of tool MB990552 in side bearing seat of gear carrier, Fig. 6.
d. Using a feeler gauge, measure clearance between the two tools and select drive pinion rear adjusting shim(s) corresponding to this measurement.
e. Install shim(s) between pinion and rear bearing, then press rear bearing onto pinion.
f. If the gear set is being replaced, install new shims of the same thickness as those previously used on the drive pinion. In determining thickness of shim pack to be used, the amount of compression of the shim pack and wear of the bearing, if the old bearing is reused, should be taken into consideration.
3. Adjust drive pinion preload as follows:
a. Install pinion preload adjusting shim between pinion spacer and front bearing. Torque end yoke to 138-180 ft. lbs. on rear differentials; 116-159 ft. lbs. on front differentials on 1984-85 models or 3.5-4.3 inch lbs. on 1986-88 models without oil seal installed.
b. Measure drive pinion preload. Preload should be 6-9 inch lbs. on 1984-85 models or 3.5-4.3 inch lbs. on 1986-88 models without oil seal installed.
c. Adjust preload, as necessary, by replacing adjusting shims or drive pinion spacers.
4. Remove end yoke, then apply a thin coat of suitable grease to lip of oil seal. Drive seal into gear carrier using tool MB990031.
5. Apply suitable grease to end yoke mating surface of seal, then install the end yoke and torque attaching nut to 138-180 ft. lbs. on rear differentials or 116-159 ft. lbs. on front differentials.