784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Caterpillar


Torque Converter

Usage:

Remove Torque Converter

Start By:

a. remove drive shaft (main)

1. Drain the oil from the torque converter and hydraulic tank.

2. Disconnect hose (2) from the top torque converter.

3. Disconnect hoses (1), (3) and (4) from the back-up clutch valve.

4. Disconnect hoses (5), (6), (7), (8) and (9) from the torque converter and brake pump.

5. Disconnect hose (10) from fitting (11).

6. Disconnect hose (12) from the torque converter inlet relief valve.

7. Disconnect hoses (13) and (14) from the torque converter housing.

8. Disconnect supply line (16) form the torque converter and brake pump.

9. Put identification marks on three wires (15) for installation purposes. Disconnect three wires (15).


Typical Example

10. The torque converter weighs approximately 680 kg (1500 lb). Install tooling (A), and fasten a hoist to it.

11. Remove the bolts that hold torque converter (17) to the engine. Remove the torque converter.

12. Remove the two O-ring seals from the front of the torque converter housing.

Install Torque Converter

1. Put O-ring (2) and (3) in position on torque converter (1) as shown.


Typical Example

2. Put torque converter (1) in position on the engine with tool (A). Make sure the spline on the torque converter clutch carrier is in alignment with the spline on the flywheel.

3. Connect hose (4) to fitting (5) on the torque converter housing.

4. Connect hose (7) from the pump drive to the top of the torque converter housing.

NOTE: Hose (6) is from the tee between the pump and valve brake. Hose (8) is from the transmission relay valve. Hose (9) is from the transmission lube port on the front right side of the transmission.

5. Connect hoses (6), (8) and (9) to the back-up clutch valve as shown.

NOTE: Hose (10) is from the hoist diverter valve. Hose (11) is from the hydraulic tank. Hose (12) is from the hydraulic tank. Hose (13) is from the brake filter. Hose (14) is from the torque converter filter.

6. Connect hoses (10), (11), (12), (13), and (14) to the torque converter and brake pump a shown.

NOTE: Hose (15) is from the torque converter filter. Hose (16) is from supply line (18). Hose (17) is from the manifold above the torque converter.

7. Connect hose (16) to the torque converter inlet relief valve.

8. Connect hoses (15) and (17) to the torque converter.

9. Connect supply line (18) to the torque converter and brake pump.

10. Connect three wires (19) to the torque converter.

11. Fill the hydraulic tank and torque converter with oil to the correct level. See the Maintenance Guide for the correct fill procedure.

End By:

a. install drive shaft (main)

Disassemble Torque Converter

Start By:

a. remove torque converter

b. remove torque converter and brake pump

1. Set the torque converter on the floor or a stand as shown.

2. Remove bolts (1) and the torque converter housing from the torque converter. Use three 3/4 " x 10 NC forcing screws if necessary. The weight of the torque converter housing is 185 kg (408 lb).

3. Remove the bolts and pilot from clutch carrier (2).

4. Remove retainer (3), the shims and the O-ring seal.

5. Remove bolts (4). Use two 5/8 " x 11 NC forcing screws to loosen clutch carrier (2). Remove the clutch carrier from the housing.

6. Remove the bolts that hold washers (5) to plate (9). Remove washer (5) and plate (9) from clutch carrier (2).

7. Remove five plates (6) from clutch carrier (2).

8. Remove piston (8) from clutch carrier (2). Remove the O-ring seal from the piston and clutch carrier.

9. Remove bearing (7) and sleeve from clutch carrier (2).

10. Remove two of the bolts that hold hub (11) to the turbine hub so two 1/2 " x 13 NC forged eyebolts can be installed.

11. Remove the turbine assembly. The weight of the turbine assembly is 28 kg (62 lb).

12. Remove the seal ring from the carrier (9). Remove race (10) and carrier (9) from hub (11).

13. Remove the remainder of the bolts that hold hub (11) to the turbine hub. Remove the turbine hub and hub (11) from turbine (12).

14. Remove two hex head bolts (16), two washers (15) and race (18) from turbine hub (13).

15. Remove bearing (14) and sleeve (17) for turbine hub (13).

16. Remove the retaining ring from shaft (19).

17. Remove bearing (20) and stator (21).

18. Remove retaining ring (22) from stator (21). Remove two plates (24), one from the top and one from the bottom of stator (21).

19. Remove cage (23) and the rollers. Remove the two springs and the roller from the cage.

20. Remove the other retaining ring from stator (21). and press the cam out of the stator.

21. Remove bolts (28) that hold hub (29) to housing (25). Remove hub (29), and remove bearing (27) from it.

22. Remove housing (25) and impeller (26) as a unit. The weight of the housing and impeller is 80 kg (176 lb).

23. Put the impeller and the housing (25) on a table as shown. Put wood blocks under the impeller.

24. Remove the bolts that hold the impeller to housing (25). If necessary, install 7/16 " - 14 x 3 in. (76.2 m) bolts. Use a soft hammer and tap on the bolts to remove the impeller from the housing.

25. Remove gear (31) from housing (25).

26. Press the sleeve out of housing (25).

27. Remove the bolts and washers (33) that hold race (32) to carrier (stator) (36). Remove the race from the carrier (stator).

28. Remove seal rings (34).

29. Remove the retaining ring and bearing (35) from the carrier (stator).

30. Remove the bolt, retainer (37), yoke (38) and the O-ring seal from the shaft.

31. Remove distributor (39) from carrier (stator) (36). Remove the lip-type seal from the distributor.

32. Remove shaft (19) from carrier (stator) (36).

33. Remove the seal rings from carriers (40) and (42).

34. If necessary, remove carrier (40), bearing (41) and carrier (42) from shaft (19) with a press.

Assemble Torque Converter

NOTE: Some of the pictures in the following procedure are typical examples. Although the pictures may look slightly different than the parts, the procedure is the same.

1. If the carriers and bearing were removed, install carrier (3), bearing (2) and carrier (1) on shaft (4) as shown.

2. Install the ring in the groove of carrier (3).

3. Install new rings in the grooves of carrier (1).

4. Put shaft (4) in position in carrier (stator) (5).

5. Install the lip-type seal in distributor (6) with the lip down as shown.

6. Install two 3/8 " - 16 NC guide bolts in carrier (5). Align the passages in distributor (6) and carrier (5). Put the distributor in position on the carrier, and install the bolts that hold it. Tighten the bolts to a torque of 54 ± 3 N·m (40 ± 2 lb ft)

7. Put clean torque converter oil on seal in distributor (6).

8. Put the yoke, O-ring seal and retainer in position on the shaft, and install the bolts that holds. Tighten the bolts to a torque of 251 ± 12 N·m (185 ± 9 lb ft).

9. Heat bearing (11) to a maximum temperature of 135° C (275° F). Put bearing (11) in position on carrier (5), and install the retaining ring that holds it.

10. Install seals (9) and (10) on carrier (5).

11. Put race (7) in position on carrier (5). Put two washers (8) that hold race (7) in position as shown, and install the bolts that hold them. Tighten the bolts to a torque of 30 ± 3 N·m (22 ± 2 lb ft)

12. Put gear (13) in position in housing (12), and install the bolts that hold it. Tighten the bolts to a torque of 54 ± 3 N·m (40 ± 2 lb ft)

13. Turn the housing over, and install the sleeve in the bore of the housing. Lower the temperature of the sleeve if necessary.

14. Put impeller (14) in position in the housing as shown, and install the bolts that hold it from the outside of the housing. Tighten the bolts to a torque of 80 ± 4 N·m (60 ± 3 lb ft)

15. Put hub assembly (15) in position on the hub and the counterbore of impeller (14). Install the bolts and hold the hub assembly, and tighten them to a torque of 54 ± 3 N·m (40 ± 2 lb ft)

16. Put bearing (16) in position on the hub assembly as shown.


NOTICE

Be careful not to damage the seals when installing the housing.


17. Put the housing with the impeller, hub assembly and bearing in it in position on the shaft and race (7) as shown.

18. Install the inner retaining ring in stator (18).

19. Install cam (17) with the wide grooves in the end of the cam away from the surface (X) in stator (18) with a press until the cam is against the retaining ring.

20. Put plate (19) in position in the stator, and stake two opposite spline teeth of the stator to hold the plate in position.

NOTE: Always replace springs (20) with new springs.

21. Put a thin layer of grease on each of rollers (22). Install rollers (22) and new springs (20) in cage (21).

22. Install the cage in cam as shown. Make sure all of the rollers are in their correct positions.

23. Put plate (23) in position in stator (18), and install the retaining ring that holds it.

24. Put stator (18) in position in the housing as shown. Make sure the stator rotates freely in a clockwise direction only. Put bearing (24) in position on top of the plate in the stator.

25. Install the retaining ring on shaft (4) to hold the stator in position.

26. Install bearing (25) in hub (26) until it is even with the surface that is down.

27. Install sleeve (27) in hub (26). Make sure the grooves on the sleeve are in alignment with the holes for rivets (30).

28. Put race (28) in position inside sleeve (27), and put two washers (29) in position as shown. Install two rivets (30) with the heads up. Flatten the opposite ends of the rivets.

29. Align the splines of the turbine hub (31) and turbine (32). Push the turbine on to the turbine hub.

30. Install two 1/2 " - 13 NC guide bolts in hub (26), and put hub (26) in position on turbine hub (31), and install six of the eight bolts that hold it. Leave the spaces for the other two bolts 180° apart.

31. Install carrier (34) and race (33) on turbine hub (31).

32. Install the seal ring in carrier (34).

33. Use two 1/2 " - 13 NC forged eyebolts, and put the turbine and turbine hub in position in the housing as shown.

34. Install the remaining two bolts that hold the turbine hub. Tighten all the bolts to a torque of 122 ± 7 N·m (90 ± 5 lb ft).

35. Install the O-ring seal in position (35). Install the O-ring seal in the hub position of clutch carrier (36).

36. Install piston (35) in clutch carrier (36).

37. Put three plates (37) (internal splines) and two plates (38) (external splines) in position on the piston. Alternate the plates during installation starting with a plate with internal splines.

38. Put plate (39) and washer (40) in position as shown, and install the bolts that hold the washers to the plate. Tighten the bolts to a torque of 54 ± 3 N·m (40 ± 2 lb ft).

39. Align the hub with the clutch discs, and put clutch carrier (36) in position on housing (12), and install the bolts that hold it. Tighten the bolts to a torque of 251 ± 12 N·m (185 ± 9 lb ft).

NOTE: Use caution when installing sleeve (41) to prevent damage to seal.

40. Install sleeve (41). Be careful not to damage the seal in the carrier. Make sure the sleeve is against the bottom of the counterbore in the clutch carrier.

41. Install bearing (42) and the upper half of race (43). Use a hammer and a soft punch to make sure they are seated.

42. Install retainer (44) on the shaft without any shims.

43. Install the bolts that hold retainer in position. Tighten the bolts to a torque of 25 N·m (18 lb ft).

44. Remove the bolts and the retainer from the shaft.

45. Measure the distance between the top half of inner bearing race (43) and shaft assembly (4) with a depth micrometer.

46. Add shims (45) as needed between the bearing race and shaft to have a clearance of 0.05 to 0.13 mm (.002 to .005 in) less than the clearance measured.

47. Install the O-ring seal on the shaft. Install the retainer on the shims. Install the bolts that hold the retainer in position. Tighten the bolts to a torque of 122 ± 7 N·m (90 ± 5 lb ft).

48. Put pilot (46) in position on the clutch carrier, and install the bolts that hold it. Tighten the bolts to a torque of 122 ± 7 N·m (90 ± 5 lb ft).

49. Put the two O-ring seals in position on the carrier (stator).

50. Align the ports in the torque converter case and the carrier, and put the torque converter case in position on the torque converter as shown. Install the bolts that hold it.

End By:

a. install torque converter and brake pump

b. install torque converter

Caterpillar Information System:

784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter & Brake Pump
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Drive Shaft (Main)
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Rear Axle Housing (Spindle)
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Final Drives, Rear Wheel Bearings & Duo-Cone Seals
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Rear Axle Shaft
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Rear Tires & Rims
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Duo-Cone Seals (Conventional & Inverted)
SUPPLEMENT FOR 793B TRUCK ENGINE Engine & Torque Converter
SUPPLEMENT FOR 793B TRUCK ENGINE Unit Injectors
SUPPLEMENT FOR 793B TRUCK ENGINE Valve Covers
SUPPLEMENT FOR 793B TRUCK ENGINE Auxiliary Drive
SUPPLEMENT FOR 793B TRUCK ENGINE Flywheel
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Transmission Filters
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter Filter Group
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter Lockup Clutch Valve
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter Inlet Relief Valve
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter Outlet Relief Valve
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Torque Converter Inlet or Outlet Relief Valve
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Transmission Electronic Speed Sensor
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Transmission Pump
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Transmission Hydraulic Control Valves
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Transmission & Transfer Gears
784B TRACTOR AND 785B OFF-HIGHWAY TRUCK POWER TRAIN Differential & Carrier
785B TRUCK MACHINE SYSTEMS Duo-Cone Seals (Conventional & Inverted)
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