Usage:
Start By:
a. remove axles
b. disassemble axle
c. disassemble brakes
Fluid Spillage Containment
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to "Tools And Shop Products Guide", NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.
NOTE: If it is necessary to work on only the differential, the brakes and axles can be removed as a unit. However the removal of the differential is only possible if the left axle and brake housings are removed from the differential housing.
NOTE: Use care when removing and handling the differential gears (ring and pinion gears). These gears are a matched set. Any damage to one will require the replacement of both.
1. Remove differential carrier (2) from differential housing (1).
2. Using tooling (A) remove differential carrier bearings (3) and (4).
NOTE: There are two different size bolts used to secure the two differential carrier halves together. It may be necessary to use heat on the twelve bolts (5) since they have been treated with thread lock.
3. Place alignment marks on both the two differential carrier halves and the ring gear. Remove twelve bolts (5) which both secures ring gear (6) to the differential carrier and the lower differential carrier half.
4. Carefully separate differential carrier half (7) from (8). Insure that all portions of the limited slip plates and discs (9) have been removed from differential carrier half (7).
5. Remove the limited slip plates and discs (9), spider gear assembly (10) and limited slip plates and discs from the other side from differential carrier half (8).
NOTE: These items can be removed as a unit by rotating carrier (8).
6. Using a press and the correct sleeve, press ring gear (6) from differential carrier half (8).
7. Remove bearing races (11) and (12) from both the left and right brake housings.
8. Remove shims (13) located behind bearing race (11) and (12).
NOTE: Based on the previous setting, there may be shims (13) behind both bearing races or on just one side.
9. Disassemble the spider assembly in the following manner.
a. Remove the limited slip plates and discs (9), thrust washer (14) and differential gear (15).
NOTE: Identify these parts as they are removed. Since there is both a left and a right side, it is important not to mix parts.
NOTE: Thrust washer (14) has a rough side and a smooth side. The smooth side of thrust washer (14) should always face differential gear (15).
b. Remove spider assembly (10) as a unit.
c. Remove four washers (17), and four spider gears (16) from spider (18).
d. Remove differential gear (19), thrust washer (20) and limited slip plates and discs (21) from the other side.
10. Using tooling (B) remove pinion nut (22), washer (23) and yoke (24) from the pinion.
11. Using a soft hammer, remove pinion gear (25) from the differential housing.
NOTE: If the pinion gear does not release from the housing easily, install nut (22) onto the top of the pinion gear. This will prevent any damage to the threads as it is being tapped. When the pinion gear does release the nut can then be removed.
12. Remove pinion gear (25) and spacer (26) from differential housing.
13. Remove pinion seal (27) from differential housing.
14. Remove inner pinion bearing race (28) and shims (29) located behind race from the differential housing.
15. Remove outer pinion bearing race (30) from differential housing.
16. Using a press and tooling (C), remove pinion bearing (31).
Assemble Differential (Rear) (All Wheel Steer)
Fluid Spillage Containment
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to "Tools And Shop Products Guide", NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.
NOTE: Use care when removing and handling the differential gears (ring and pinion gears). These gears are a matched set. Any damage to one will require the replacement of both.
NOTE: Preform the following measurements and calculations with the greatest amount of accuracy possible. Any errors will result in faulty contact patterns which could result in premature differential failure.
NOTE: The following steps are required to correctly install the pinion gear into the differential housing.
1. Read dimension "X" which is stamped into differential housing case (1) in the approximate location shown. Example 163.20 mm. This dimension is a measurement in millimeters
NOTE: It may be necessary to clean the differential case in the area shown to uncover the dimension numbers. Use a wire brush to remove dirt and layers of paint. The dimension numbers will consist of three numbers, a period and another two numbers.
NOTE: If no measurement numbers are stamped into the differential case or if the differential case must be replaced see step 6 in this story for the necessary measurement and calculation procedure for pinion setting.
2. Read dimension "I" located on the end of pinion gear (2). Dimension "I" will consist of three numbers, followed by a period, followed by either one or two other numbers. Example 125.05 mm. This dimension is a measurement in millimeters.
3. Using a depth gauge, measure the width of inner pinion bearing (3) with the cone and bearing race. This measurement will be dimension "II". Example 36.65 mm.
4. Add dimension "I" to Dimension "II" to get dimension "Y".
EXAMPLE
5. Subtract dimension "Y" from dimension "X".
EXAMPLE
NOTE: The following procedure is required to obtain dimension "X" (the differential case dimension) if it is not stamped into the case.
6. Install tooling (A) as shown.
7. Install adjusting piece of tooling (A) into the center of left brake housing (4) as shown.
8. Using alignment marks on brake housing (4) and differential housing (1) and alignment pin in brake housing, install brake housing to differential housing. Use approximately six bolts and washers to secure left brake housing to differential housing.
9. Install tooling (B) and tooling (C), to the right side of the differential housing.
10. Install tooling (D) into differential housing as shown. Using adepth gauge with a long probe measure dimension (A). Dimension "A" is the distance from the outer surface of tooling (D) gauge ring to the center of tooling (C) measuring shaft. Note that tooling (C) measuring shaft, has a notch cut into it to allow for center measurement. Example dimension "A" is 275.80 mm.
NOTE: This is a critical measurement. Measure dimension "A" several times to insure accuracy.
11. Remove tooling (A) from the differential housing.
12. Determine dimension "B" according to draft. Measure the inside dimension of differential housing (1) at the pinion bore. Example dimension "B" is 112.60 mm.
13. Subtract dimension "B" from dimension "A".
EXAMPLE
14. Read dimension "I-1" located on the end of pinion gear (2). Dimension "I-1" will consist of three numbers, followed by a period, followed by either one or two other numbers. Example 125.05 mm. This dimension is a measurement in millimeters.
15. Using a depth gauge, measure the width of inner pinion bearing (3) with the cone and bearing race. This measurement will be dimension "II-1". Example 36.65 mm.
16. Add dimension "I-1" to Dimension "II-1" to get dimension "Y-1".
EXAMPLE
17. Subtract dimension "Y-1" from dimension "X-1".
EXAMPLE
18. Using tooling (E), install shims (5) and inner bearing race (6) to the differential housing.
19. Using the proper sleeve, press inner bearing race (6) into place until it is fully seated.
20. Using tooling (F), install outer bearing race (7) in pinion bore of differential housing.
21. Heat pinion bearing (8) and install onto pinion shaft (9).
22. Install tooling (G) on the collar of pinion shaft (9).
NOTE: Drive roll pins far enough out of the gauge ring bores that the roll pins can be passed back at the tightening of the nut, thus giving a correct measurement result.
22. Position pinion shaft (9) and heated bearing (10) and install bearing onto shaft until complete contact is obtained.
24. Install yoke (11), washer (12) and nut (13).
NOTE: Do not install pinion seal at this time.
25. Tighten nut (13) until a rolling torque of 1 to 2 N·m (.7 to 1.4lb ft) is obtained.
26. Remove nut, washer, yoke, pinion gear and tooling (C) gauge ring from differential housing.
27. Carefully remove tooling (G) and determine dimension "X". Example 16.73 mm.
NOTE: Dimension "X" corresponds to the height of the spacing ring (15) to be installed.
NOTE: After determining dimension "X", consult Caterpillar publication SENR5826 Systems Operation Testing & Adjusting for 438B Backhoe Loader. See page 4 to obtain a total listing of all dimensions and corresponding spacers.
28. Install pinion bearing (10) back into differential housing. Using tooling (H), install pinion seal (14). After installation, put a small amount of lubricant on the seal to protect it during assembly.
NOTE: Insure that bearing (10) is properly installed prior to installation of pinion seal (14).
29. Install pinion (9), spacing ring (15), into the differential housing and through outer pinion bearing (10) and pinion seal (14). Apply some 9S3263 Threadlocker to the threads of pinion (9). Install yoke (11), washer (12) and nut (13).
30. Tighten nut (13) until a rolling torque of 1 to 2 N·m (.7 to 1.4lb ft) is obtained. Do not exceed 600N·m (444 lb ft) of torque on nut (13). It will be necessary to tighten nut (13) a small amount and check the rolling torque. Repeat this procedure as many times as necessary to produce the proper rolling torque.
31. Install roll pins into differential carrier half.
32. Using a press and the proper size sleeve, install bevel gear onto differential carrier half (17).
33. Assembly plates (18), discs (19), thrust washer (20), and side gear (21) of the limited slip differential in the following manner.
a. Install thrust washer (20) onto the splines of side gear (21). Insure that the smooth side of thrust washer (20) is facing side gear (21).
b. Install plate (18) on top of thrust washer (20).
c. Alternate discs (19) and plates (18) on top of each other until all are used. Align the tabs of all of plates (18).
d. Do this procedure to both sets of limited slip discs and plates.
e. Measure the thickness of thrust washer (20), plates (18) and discs (19). The measurements on both sets should be identical.
34. Install side gear (21), thrust washer (20), plates (18) and discs (19) as a unit into differential carrier half (17).
35. Assemble four spider gears (22) onto spider (24). Install four thrust washers (23) onto spider (24).
NOTE: Insure that the tabs on each thrust washer (23) is pointed upward. This will allow it to lock into the upper differential carrier half.
36. Install spider assembly (24) into the lower differential case half (17).
37. Install second set of preassembled and measured limited slip discs and plates (25) into upper differential case half (26).
38. Install upper differential case half (26) onto lower differential case half (17).
NOTE: Insure that all four tabs of thrust washers (23) fit into the slots in the upper differential case half.
39. Holding both halves together, turn the entire differential carrier case over and install three or four bolts (27) to secure both units together.
40. Turn the entire unit over again. Install tooling (J) as shown to check for end play within both sides of the limited slip portion of the differential.
41. End play should be, between 0.10 to 0.15 mm (.004 to .006 in). If the end play is greater than this, replace plates (18).
42. Turn differential over and remove bolts (27). Make any necessary adjustments to the limited slip. Lubricate all internal components.
43. Reinstall upper differential case half to lower differential case half. Insure that thrust washer tabs fit into the upper differential case half slots.
44. Place both differential case halves together in a press and apply pressure. Apply some 9S3263 Threadlocker to the threads of bolts (27) and bolts (28) and tighten.
45. Tighten eight bolts (27) to a torque of 300 N·m (222 lb ft). Tighten four bolts (28) to a torque of 120 N·m (88 lb ft).
46. Using a press and the proper plate, press both differential carrierbearings (29) onto the carrier. Press on until the bearing reaches the shoulder.
NOTE: See the section of this publication titled Assemble Brakes. It is necessary that the studs which hold the brake piston be assembled prior to proceeding with the differential assembly. Also a seal must be installed and the left brake housing secured to the differential.
47. Install O-ring seal (30) and install left brake housing (31) to the differential housing. Check alignment marks on both brake housing (31) and differential housing to insure proper alignment. Use several bolts and washers to secure the brake housing to the differential housing.
48. Insert shims (32) equaling a value of 1.75 mm (.07 in) in the bearing bore of left brake housing. Install bearing outer race (33). Drive into position until shims contact shoulder.
49. Install differential carrier (34) back into differential housing.
50. Insert the bevel gear side bearing outer race (35) into tooling (B).
51. Remove spring pin on the right side of the differential housing. Bolt tooling (B) to the differential housing. Turn the adjusting hub in the center of tooling (B) until no backlash and no pressure are present.
NOTE: Rotate the pinion numerous times to insure that these conditions exist prior to proceeding to the next step. When this is complete use the locking bolt on top of tooling (B) to secure the center hub.
52. Install tooling (K) and tooling (J) as shown. With the pinion gear held stationary, move the bevel gear. The backlash should be .15 to .25 mm (.006 to .0010 in) Release the locking bolt on tooling (B) and rotate the center hub until this measurement is achieved. Once the proper setting is accomplished, reset the locking bolt.
NOTE: This measurement is critical to the proper performance of the unit. Perform this function several times to insure accuracy.
53. After the backlash adjustment has been satisfactorily completed, remove tooling (B), (J), and (K). Separate tooling (B) from the differential housing and remove bearing race (35) from tooling (B).
54. Determine dimension "I". Using a depth gauge, measure the distance from the flange mounted surface to the contact face of the bearing outer race.
EXAMPLE
55. Determine dimension "II". Using a depth gauge, measure the distance from the flange mounted surface of the right brake housing to the contact face of the bearing outer race.
EXAMPLE
56. Calculate and install shim (36) for right brake housing. Install shim and install bearing outer race. Press into place until shim makes contact with housing shoulder.
EXAMPLE
57. Apply Prussian blue to the teeth of the bevel gear. Install spring pin remove earlier from differential housing Install O-ring (37) on right brake housing. Install proper lifting device and align right brake housing to differential housing. Fasten right brake housing (37) to the differential housing using two bolts and washers.
58. Move the pinion gear back and forth several times following the procedure in step 60 to determine proper contact pattern.
59. Separate the right brake housing from the differential housing and check for any incorrect contact pattern that would cause excessive wear. If necessary perform steps 48 through 58.
60. After the gear clearance (backlash) and bearing preload adjustments have been made, check the tooth contact setting between the bevel gear and pinion as follows:
a. Put a small amount of marking compound (Prussian blue) on the bevel gear teeth. Turn the pinion in both directions, and check the marks made on the bevel gear teeth.
Correct Tooth Contact Setting
b. With no load, the correct tooth contact setting will be as shown. The correct area of tooth contact is located equally on both sides and starts near the toe of the gear and goes 30% to 50% up the length of the tooth. With this setting, when a load is put on the gear, the load will be over the correct area of the teeth.
Short Toe Contact Setting
c. If the pinion shaft is too far away from the bevel gear, short toe contact will be the result as shown. The teeth of the pinion will be in contact with the toe ends of the convex faces (part that makes a curve toward the outside), and the top edge of the heel end of the concave faces (part that makes a curve toward the inside). To correct this, remove shims from behind the inner pinion bearing. After this is done, check the gear clearance (backlash) and tooth contact again.
Short Heel Contact Setting
d. If the pinion shaft is too near to the center of the bevel gear, short heel contact will be the result as shown. The teeth of the pinion will be in contact with the toe ends of the concave faces (part that makes a curve toward the inside) and the heel ends of the convex faces (part that makes a curve toward the outside). To correct this, add shims behind the inner pinion bearing race. After this is done, check the gear clearance (backlash) and tooth contact again.
NOTE: Several adjustments of both pinion and bevel gear may be needed before correct tooth contact and gear clearance (backlash) is made. Always remember that a change to gear clearance (backlash) will also change the tooth contact. Therefore, be sure gear clearance (backlash) is in correct adjustment before tooth contact is checked.
e. After gear clearance (backlash) and tooth contact are correct, remove the extra marking compound (Prussian blue) from the bevel gear and pinion.
End By:
b. assemble axles
a. install axles
c. assemble brakes
install axles