4 Pinion Differential
DISASSEMBLYTypical 4 Pinion Differential Assembly:
1. Using a 1/2 inch drill bit and press, drill each drive gear rivet to a 3/4 inch depth. Then, using a suitable punch, drive out rivet shanks. During this operation, ensure differential is secure in a vise, applying tensile load to final drive gear.
2. Remove final drive gear using an arbor press. To separate differential, insert a 9/16 in. deep well socket into axle hole on final drive gear side, then using a suitable bearing puller, attempt to remove bearing using the socket as a reaction plate. Differential case halves should separate.
3. Remove left side gear from case, then remove differential bearings.
4. Lift speedometer gear from case, then using a suitable drill bit, drill center of pinion shaft roll pins and drill on through case walls.
5. Using holes drilled in step 4, use tool No. T83P-4204-A to drill case roll pins, then use a suitable punch to remove pins.
6. Remove pinion shafts and gears, pinion seat, thrust washers an right side gear.
ASSEMBLY
NOTE: Clean, inspect and lubricate all parts prior to reassembly.
1. Position right side gear and thrush washer in right case half, then install pinion shafts only to retain the position of the pinion gear and thrust washers.
2. Install pinion shaft seat and long pinion shaft into case, opposite pinion gear.
3. Insert two short pinion shafts and drive the three roll pins about 3/8 inch below case mating surface.
4. Align left side gear, thrust washer and pinion gear to ensure proper gear mesh, then assemble case halves, aligning holes in right and left case halves with their respective roll pins.
5. Install speedometer drive gear, tangs face up, then press differential bearings into place using tool No. T83P-4220-CH.
6. Align bolt holes of final drive gear and case flange, making contact with final drive gear in two opposite points, then press into case. The special service bolts and nuts provided to replace rivets must be used to provide proper clearance with transaxle case.
7. Install bolts with head toward differential case, and nuts against final drive gear, finger tighten, then torque nuts to 80 to 100 ft lbs (108-135 Nm).
8. To adjust differential bearing preload, refer to following steps:
a. Remove differential seal from transaxle case using drift. Remove differential bearing cup from transaxle case using tool T77F-4222A or equivalent.
b. Remove preload shim located under bearing cup.
Installing Tool T81P-4451B Into Clutch Housing:
c. With differential installed position in clutch housing, install Height Gauge Spacers T81P-4451B or equivalent onto clutch housing dowels.
Installing Shim Selector Tool Over Differential Bearing Cup:
d. Position bearing cup removed from transaxle case onto differential bearing, then install shim selector tool T81P-4451B or equivalent over differential bearing cup.
e. Position transaxle case onto height gauge spacers. Install four bolts supplied with tool and torque bolts to 17-21 ft lbs (23-28 Nm).
Positioning Gauge Bar Tool Across Shim Selector Tool:
f. Position gauge bar tool T80L-77003A or equivalent across shim selector tool.
Differential Selective Shim Chart:
g. Using feeler gauge, measure gap between gauge bar and selector tool gauge surface. Obtain measurements from two positions around tool and take average of readings to determine necessary shim thickness. Refer to chart for available shim sizes. If shim size required is not on chart, select next thickest shim size.
Installing Bearing Cup Into Differential Case:
h. Install shim into transaxle case using tools T77F-1176A, T75T-1225A and T73T-4222B or equivalent. Ensure cups seats full into cover.
i. Install differential seal using suitable installation tool.