Service
Fig. 7 Nut From Bevel Pinion Shank Removal:
DISASSEMBLE
1. Using holder tool No. 09930-40113, or equivalent, Fig. 7, remove nut from end of bevel pinion shank.
2. Scribe identification marks on each cap bolted to the saddle portion of carrier case and the caps holding down the side bearings.
3. On each side, loosen bolts on bearing adjuster stopper and remove bearing cap attaching bolts, then bearing cap.
4. Remove differential case assembly from carrier.
5. Remove ten bolts attaching bevel gear to differential case, then separate gear from case.
Fig. 8 Differential Case Halves Separation:
6. Using holder tool, Fig. 8, remove bolts securing the two differential case halves, then separate case halves.
7. Remove side gears, differential pinions and thrust washers.
Fig. 9 Side Bearing From Differential Case Half Removal:
8. Using puller tool No. 09913-60910 and adapter tool No. 09913-85230, or equivalents, Fig. 9, remove side bearing from each differential case half.
9. Using a suitable puller and an arbor press, remove inner race of bevel pinion bearing.
ADJUSTMENT AND INSPECTION
Fig. 10 Side Gear Backlash Measurement:
SIDE GEAR BACKLASH
1. Assemble differential gearing and case as shown, Fig. 10. Torque case half bolts to 27-32.5 ft. lbs.
2. Using a suitable vernier caliper and a piece of solder as shown, Fig. 10, measure side gear backlash. Backlash should be 0.002-0.006 inch 0.05-0.15 mm).
3. Using a suitable dial indicator, measure side gear thrust play. Thrust play should be 0.005-0.014 inch 0.0.12-0.37 mm).
Fig. 11 Side Gear Thrust Washer Chart:
4. If measurements are not within specifications, increase or decrease thickness of thrust washers on inner side of each case half with appropriate thrust washer as shown, Fig. 11.
BEVEL PINION SHIM THICKNESS
Thickness of shims to be used on bevel pinion varies from one vehicle to another due to machining during assembly. Therefore, for each vehicle, the thickness of shims necessary for locating pinion in correct (producing proper backlash between pinion and gear) must be determined when reassembling.
To facilitate this determination, a two piece dummy tool is available. The following procedure is based on the use with the dummy tool set in the carrier, without any shims as follows:
Fig. 12 Dial Indicator On Dummy Pinion Installation:
1. Install a suitable dial indicator on dummy pinion, allowing indicator spindle to protrude 5-6 mm from bottom of pinion dummy as shown, Fig. 12.
Fig. 13 Dummy Pinion On Surface Plate Installation:
2. Rest dummy on surface plate, then set dial indicator to zero, Fig. 13.
3. Install dummy pinion with bearings into carrier, then the joint flange.
Fig. 14 Pinion Starting Torque Measurement:
4. Tighten bevel pinion by hand, then install differential gear preload adjuster tool No. 09922-75221, or equivalent, Fig. 14, on universal joint flange.
5. Using a suitable spring scale, turn pinion several times, then tighten pinion nut gradually until pinion starting torque reaches 4.0-7.5 lbs., Fig. 14.
Fig. 15 Shim Thickness Selection:
6. Refer to Fig. 15, noting the three dimensions, a, b and c. The value of "b" is unknown at this time. The values of "a" and "c" are given. The sum "a + c", is 94 mm, which is indicated on the dummy tool.
7. With dummy tool installed, the dial indicator pointer may have deflected from "0" mark to a certain value, note value, that value is now "b". Add this value to 94 mm and from the total, subtract value marked on bevel pinion. The remainder is the required shim thickness.
Fig. 16 Bevel Pinion Shim Thickness Chart:
8. There are 12 selective shim thicknesses. Select one or two shim(s) from chart, Fig. 16, to obtain the closest thickness to required thickness, then install shim piece into clearance as shown, Fig. 15.
Fig. 6 Mounting Bracket Removal:
PINION BEARING PRELOAD
The bevel pinion, installed in the carrier, is required to offer a certain torque resistance when checked by using preload adjuster tool, Fig. 6. This resistance is a preload which is due to the tightness of the two tapered bearings by which the pinion is held in carrier. This tightness is determined primarily by tightening torque of bevel pinion nut. Pinion bearing preload should be 7.8-14.7 inch lbs. Adjust preload of bevel pinion bearings, as follows:
1. Install pinion bearings, spacer, bevel pinion, oil seal and universal joint flange to differential carrier. Apply gear oil to bearings and grease oil seal lip.
2. Tighten bevel pinion nut by hand, then install preload adjuster tool to universal joint flange.
3. Turn pinion several times, then tighten pinion nut gradually while checking pinion starting torque, using a suitable spring scale, Fig. 6. Starting torque should be 4.0-7.5 lbs.
4. Stake bevel pinion nut to prevent it from loosening. Pinion bearing preload is adjusted by tightening bevel pinion nut to compress spacer. Use a new spacer for adjustment. If specification exceeds limit, replace spacer and repeat preload adjustment procedure.
Fig. 17 Backlash Between Bevel Gear & Pinion Measurement:
BEVEL GEAR BACKLASH
Backlash between bevel gear and pinion is checked using a suitable dial indicator as shown, Fig. 17. The differential case assembly is mounted in the normal manner and fastened down by tightening side bearing cap bolts to 7.7-14 ft. lbs. Screw in each adjuster until it contacts bearing outer race so that outer race is prevented from inclining. The dial indicator spindle is pointed squarely to "heel" on drive side (convex side) of gear tooth. Hold bevel pinion, then turn gear back and forth. Bevel gear backlash should be 0.004-0.006 inch 0.10-0.15 mm).
Fig. 18 Drive Bevel Pinion Graphic Chart:
To increase or decrease backlash, displace bevel gear toward or away from pinion by turning in one adjuster and turning out the other by equal amounts.Turning adjuster one notch changes backlash approximately 0.002 inch (0.05 mm). Adjust preload on side bearing during backlash adjustment using a suitable spring scale and mounting preload adjuster tool as shown, Fig. 14. If reading at bevel gear starts moving within range given, Fig. 18, side bearing preload is acceptable. Referring to Fig. 18, for example, when drive bevel pinion bearing preload measures 5.73 lbs., drive bevel pinion bearing preload + bevel gear side bearing preload should be 6.17-7.05 lbs. After adjustment, torque bearing cap bolts to 51-72 ft. lbs.
ASSEMBLY
Reverse disassemble procedure to reassemble, noting the following:
1. The bevel pinion and bevel gear are replaced as a set. Even when only the bevel pinion or bevel gear replacement is necessary, ensure to replace both as a set.
2. When installing differential pinion shaft into differential case, ensure to install longer end of shaft first into pinion joint.
3. The bolts securing bevel gear to differential case are subject to shear stress, since drive is transmitted by these bolts from gear to case. These are special bolts made from chrome steel and must never be replaced by common bolts. Apply Loctite to threads of bolts before installing them.
4. Using bearing installer tool No. 09940-53111, or equivalent, and a press, install differential side bearings into differential case.
5. A press must be used to install two tapered roller bearings on bevel pinion. Outer races are press fitted into the differential carrier and inner races onto the pinion.
6. After installing bevel pinion, spacer, bearings and universal joint flange to carrier, and completing bevel pinion bearing preload adjustment, stake bevel pinion nut to prevent it from loosening.
7. When installing side bearing caps, ensure match marks scribed at the time of disassemble align, then after completing bevel gear backlash adjustment, torque cap bolts to 51-72 ft. lbs.