Usage:
Disassemble Front And Rear Differentials (920 Only)
start by:
a) remove front or rear differential
1. Put the differential and carrier assembly on tooling (A) with the bevel gear down as shown.
2. Remove the bolts that hold pinion housing (1) to carrier assembly (2).
3. Install two 3/8"-16 NC forged eyebolts in the top of housing (1) and fasten a hoist to it.
4. Use two 1/2"-13 NC forcing screws to loosen housing (1) from carrier assembly (2). Remove the housing and pinion gear as a unit. The weight of the unit is 70 lb. (32 kg).
5. Remove shims (4) from carrier assembly (2). Put identification on the shims for assembly purposes.
6. If necessary, remove pin (3) from carrier assembly (2).
7. Bend the tab of the lock from nut (5). Use tool (B) and remove nut (5), the lock and nut (6) from the pinion shaft.
8. Remove the pinion shaft from the pinion housing with tooling (C).
9. Remove the small bearing cone and the O-ring seal on the bottom of the pinion housing.
10. Remove the small bearing cup from the pinion housing with tooling (D).
11. Remove the large bearing cup from the pinion housing with tooling (E).
12. Remove the large bearing cone from the pinion shaft with tooling (F).
13. Fasten a hoist to the carrier assembly and turn it over on tooling (A) with the bevel gear up as shown. The weight of the assembly is 160 lb. (72 kg).
14. Remove the lockwire from bolts (7) and (8). Remove bolts (8) and locks (9) from the carrier assembly.
15. Remove bolt (10) and the lock from the differential group.
16. Use a hammer and punch to remove dowel (11) from the end of the differential case shown.
17. Remove pinion shaft (12) from the differential case.
| NOTICE |
|---|
When the pinion shaft is removed the thrust washers for the pinions can fall out. |
18. If necessary, turn the side gears to remove pinions (13) and the thrust washers.
19. Remove side gears (14) and the thrust washers from the differential case.
20. Remove adjustment nuts (15) from each side of the carrier assembly.
21. Put identification marks on bearing caps (16) and (17) as to the location on the carrier assembly.
22. Put a bar through the differential group and fasten a hoist to it. Remove the bolts and remove bearing caps (16) and (17). Remove the differential group and bearing cups from the carrier assembly. The weight of the differential group is 70 lb. (32 kg).
23. Remove bolts (18) and the locks to remove ring gear (19) from the differential case.
24. Use tooling (G) to remove the bearing cones from the differential case.
Assemble Front And Rear Differential (920 Only)
1. Heat bearing cones (1) and (2) to a maximum temperature of 275°F (135°C). Install bearing cones (1) and (2) on the differential case.
2. Put ring gear (4) in position on the differential case and install the locks and bolts (3) to hold it. Tighten bolts (3) to a torque of 98 ± 7 lb.ft. (134 ± 10 N·m).
3. Put carrier assembly (6) on tooling (A) as shown.
4. Install the bearing cones on the differential group bearings. Put a bar through the differential group and fasten a hoist to it.
5. Install the differential group in carrier (6) so that the ring gear is toward dowel hole (5).
6. Install bearing caps (8) on the carrier assembly. Make sure the threads in the bearing caps and carrier assembly are in alignment and tighten the bolts.
7. Install adjustment nuts (7) hand tight.
8. Install side gears (9) and thrust washers (10) in the differential case. The groove in washers (10) must be toward gears (9).
9. Put pinions (12) and thrust washers (11) in position on the side gears. Turn the side gears to make an alignment of the holes in the pinions with the holes in the differential case.
10. Put pinion shaft (13) in position and install pin (14), the bolt and lock to hold shaft (13).
11. Fasten a hoist to the differential group and carrier assembly (6) and put the unit in tooling (A) as shown.
NOTE: Use spacers between carrier assembly (6) and tooling (A) when the carrier assembly is fastened to the tooling.
12. Lower the temperature of the pinion shaft bearing cups and install them in pinion housing (15).
13. Put clean oil on O-ring seal (16) and install it around housing (15).
14. Heat larger bearing cone (18) to a maximum temperature of 275°F (135°C). Install bearing cone (18) on pinion shaft (17) as shown.
15. Put pinion shaft (17) in housing (15). Heat small bearing cone (19) to a maximum temperature of 275°F (135°C). Install bearing cone (19) on pinion shaft (17).
16. Install nut (22), lock (21) and nut (20) on the pinion shaft. Make sure the chamfered edges of the nuts are away from the pinion shaft bearing and do not tighten nut (20).
17. Install tool (B) on the outside nut and tighten the inside nut until a torque of 6 to 10 lb.in. (0.7 to 1.1 N·m) is needed to turn the pinion shaft through tool (C).
18. Remove tool (B) and tighten the outside nut and bend the tab of the lock in the nut.
19. Install the spring pin and shims (23) equal to the original thickness on carrier assembly (6).
20. Install two 1/2"-13 NC x 6 in. long guide bolts in carrier assembly (6).
21. Fasten a hoist to housing (15) and put it in position in carrier assembly (6). Install three bolts the same distance apart to hold the housing in position.
22. To make an adjustment of the differential bearing preload and the gear clearance (backlash) between the bevel gear and pinion use the following procedure:
a) Tighten the adjustment nuts until there is a small amount of preload on the bearings.
b) Install tool group (C) on the bevel gear as shown to check the gear clearance (backlash) at four locations around the bevel gear 90° apart. Use the lowest indication on tool group (C) as the correct gear clearance (backlash) value. The correct gear clearance backlash is .005 to .010 in. (0.13 to 0.25 mm).
c) If the gear clearance (backlash) is too much, loosen the upper adjustment nut and tighten the lower adjustment nut the same amount to change the gear clearance (backlash). If the gear clearance (backlash) is not enough, loosen the lower adjustment nut and tighten upper adjustment nut the same amount to change the gear clearance (backlash).
d) Tighten the upper adjustment nut until a torque of 30 to 50 lb.in. (3.4 to 5.7 N·m) is needed to turn the pinion shaft.
e) Check the gear clearance (backlash) again as in Steps b and c.
23. To check the tooth contact setting between bevel gear and pinion after the gear clearance (backlash) and bearing preload adjustments have been made use the following procedure:
a) Put a small amount of prussian blue, red lead or paint on bevel gear teeth. Turn pinion and check marks made on bevel gear teeth.
ALIGNMENT OF BEVEL GEAR AND PINION
CORRECT TOOTH CONTACT SETTING
b) With no load, correct tooth contact setting will be as shown. The area of contact starts near toe of gear and goes about 30% up the length of tooth. With this setting, when load is put on gear, it will be over the correct area of teeth.
SHORT TOE CONTACT SETTING
c) If bevel pinion shaft is too far away from bevel gear, short toe contact will be the result as shown. The teeth of pinion will be in contact with toe ends of convex faces (part that makes a curve toward the outside), and top edge of heel end of concave faces (part that makes a curve toward the inside). To correct this, move pinion shaft toward gear by a decrease of the shim thickness between pinion housing and carrier. After this is done, check gear clearance (backlash) and tooth contact again.
SHORT HEEL CONTACT SETTING
d) If bevel shaft is too near to center of bevel gear, short heel contact will be the result as shown. The teeth of pinion will be in contact with toe ends of concave faces (part that makes a curve toward the inside) and the heel ends of convex faces (part that makes a curve toward the outside). To correct this, move pinion shaft away from gear by an increase of the shim thickness between pinion housing and carrier. After this is done, check gear clearance (backlash) and tooth contact again.
NOTE: Several adjustments of both pinion and bevel gear can be needed before correct tooth contact setting and gear clearance (backlash) is made. Always remember that a change to gear clearance (backlash) will also change the tooth contact setting. Be sure gear clearance (backlash) is in correct adjustment before tooth contact is checked.
e) After correct gear clearance (backlash) and tooth contact setting is made, remove extra prussian blue, red lead or paint from bevel gear and pinion.
24. Install locks and bolts for adjusting nuts. Put lockwire on the four bolts for bearing caps. Remove the two guide bolts and install remainder of bolts that hold the housing. Remove differential and carrier assembly from tooling (A).
end by:
a) install front or rear differential