Usage:
Start By:
a. remove hoist and brake cooling pump
b. remove transmission pump*
*See the 793B Truck Power Train, Disassembly And Assembly Manual for this information.
Typical Example
1. Disconnect hoses (2), (5) and (7) from the pump drive.
2. Remove the bolt at location (4). Move the clips and hose assemblies away from the pump drive.
3. Remove guard (3) from the pump drive. Remove the four bolts that hold the hydraulic pump drive shaft (1) to the yoke assembly in the pump drive.
4. Install tool (A) at location (4), and fasten a hoist to it. The weight of the pump drive is approximately 68 kg (150 lb).
5. Remove four bolts (6) and the pump drive.
NOTE: The following steps are for installation of the pump drive.
6. Put the pump drive in position with tool (A) and a hoist. Install bolts (6) that hold the pump drive in position. Remove tool (A).
7. Put hydraulic pump drive shaft (1) in position on the yoke assembly of the pump drive, and install the bolts that hold it. Tighten the bolts to a torque of 55 ± 7 N·m (41 ± 5 lb ft).
8. Put guard (3) in position, and install the bolts that hold it.
9. Connect hoses (2), (5) and (7).
10. Put the two hose assemblies and clips in position at location (4), and install the bolt that holds them in place.
End By:
a. install transmission pump*
b. install hoist and brake cooling pump
* See the 793B Truck Power Train, Disassembly And Assembly Manual for this information.
Disassemble Pump Drive
The photos shown are from a 777 truck. The procedures similar for the 793B Truck.
Start By:
a. remove pump drive
Typical Example
1. Remove bolts and washers (1) that hold bearing cage (2) to the housing.
2. Install two 1/2" -13 NC forcing screws (3), and remove the bearing cage.
3. Remove shims (5) and O-ring seal (6) from the inside of cage (2). Inspect the seal, and make a replacement if needed.
4. Remove bearing cup (4) from the cage if a replacement is necessary.
5. Remove bearing cones and gear assembly (7) from the housing.
6. Use tooling (A) to remove bearing cones (8) from each side of the gear if a replacement is necessary.
7. Remove six bolts and washers (9) that hold the bearing cage to the housing.
8. Install two 1/2" - 13 NC forcing screws, and remove bearing cage (10).
9. Remove shims (13) and O-ring seal (12). Inspect the seal, and make a replacement as needed.
10. Remove bearing cup (11) from the cage if a replacement is necessary.
11. Remove bearing cones (14) and (16) and gear (15). Remove bearing cones (14) and (16) from each side of the gear with tooling (A).
12. Remove yoke assembly (17) from the housing.
13. Remove the bolts from shaft (19), and install two 1/2" - 13 NC forcing screws. Remove the shaft and shims (18) from the gear and bearing assembly.
14. Remove spacer (20) and bearing (21) from shaft (19). The bearing slides off the shaft with hand pressure. Remove O-ring seal (22), and inspect it. Make a replacement of the seal if necessary.
15. Remove gear (23) and the bearing after shaft (19) has been removed.
16. Remove bearing cups (24) from gear (23) if replacements are necessary. Remove ring (25) if a replacement is necessary.
17. Remove the bearing cup from the housing with tooling (B).
18. Inspect the lip-type seal (26) and bearing cup (27). If seal (26) or bearing cup (27) are worn or damaged, use a new parts for replacement.
Assemble Pump Drive
1. Install the lip-type seal in the housing with tooling (A). Be sure the lip of the seal is toward the inside of the housing.
2. Turn the housing over. Lower the temperature of bearing cup (27). Use tooling (A) to install the bearing cup.
3. Use tooling (A) to install the other bearing cup (not shown) in the housing. Lower the temperature of the bearing cup prior to installation.
4. Install ring (25) in gear (23).
5. Lower the temperature of bearing cups (24). Use tooling (A) to install bearing cups (24) in gear (23).
6. Put gear (23) and bearing cone (28) in position in the housing.
7. Use the procedure that follows to adjust the preload on bearing cones (21) and (28):
a. Install bearing cone (21) and ring (20) on shaft (19). Put the shaft (without shims and O-ring seal) in position in the housing and through gear (23) and bearing cone (28).
b. Install four bolts (29). Tighten the bolts evenly to a torque of 7 ± 1 N·m (5 ± 1 lb ft). Measure the distance between the housing and shaft (19) at three locations. Make a shim pack (18) of the same thickness as the average measured distance minus 0.10 mm (.004 in).
8. Remove shaft (19). Install O-ring seal (22) on the shaft.
9. Install the correct amount of shims (18) and shaft (19).
10. Put yoke assembly (17) in position in the housing.
11. Heat bearing cones (14) and (16) to a maximum temperature of 135° C (275° F). Install the bearings on each side of gear (15).
12. Install gear (15) in the housing. Make sure the splines on the yoke assembly and the splines on the gear assembly are in alignment.
13. Lower the temperature of the bearing cup. Use tooling (A) to install the cup in bearing cage (10).
14. Use the procedure that follows to adjust the end play of gear (15):
a. Install bearing cage (10) (without O-ring seal and shims). Tighten bolts (9) evenly until a small resistance is felt in the rotation of gear (15).
b. Measure the distance between the housing and cage (10) at three locations. Make a shim pack (13) of the same thickness as the average measured distance plus 0.10 mm (.004 in).
15. Remove bearing cage (10). Install O-ring seal (12) on bearing cage (10).
16. Install the correct amount of shims (13) and bearing cage (10). Use tooling (B) to measure the end play of gear (15). End play must be 0.05 to 0.15 mm (.002 to .006 in). Add or remove shims (13) to get the correct end play.
17. Heat bearing cones (8) to a maximum temperature of 135° C (275° F). Install the bearings on each side of gear (7).
18. Install gear (7) in the housing.
19. Lower the temperature of the bearing cup. Use tooling (A) to install the cup in bearing cage (2).
20. Use the procedure that follows to adjust the end play of gear (7):
a. Install bearing cage (2) (without O-ring seal and shims). Tighten bolts (1) evenly until a small amount of resistance is felt in the rotation of gear (7).
b. Measure the distance between the housing and cage (2) at three locations. Make a shim pack (5) of the same thickness as the average measured distance plus 0.10 mm (.004 in).
21. Remove bearing cage (2). Install O-ring seal (6) on bearing cage (2).
22. Install the correct amount of shims (5) and bearing cage (2). Use tooling (B) to measure the end play of gear (7). End play must be 0.05 to 0.15 mm (.002 to .006 in). Add or remove shims (5) to get the correct end play.
| NOTICE |
|---|
After assembly, put in .946 liter (1 U.S. quart) of SAE 10W oil in the oil pump drive housing before the engine is started. |
End By:
a. install pump drive