Axle and Differential Front Disassembly / Assembly
AXLE AND DIFFERENTIAL FRONT DISASSEMBLY / ASSEMBLY
Disassembly
1. Remove the front axle assembly.
2. Install the axle on bench.
Note:
^ Place a suitable drain pan under the axle.
3. Drain the axle fluid.
1 Remove the ten differential cover bolts.
2 Remove the differential cover.
4. Remove the axle shaft using a jerking motion.
5. Use Converter Seal Remover ST 49 UN01 0870 or equivalent and Impact Slide Hammer ST 49 0223 630B and Adapter ST 49 UN11 101 to remove the LH axle seal.
6. Use Bearing Cup Puller ST 308-047 or equivalent and Impact Slide Hammer ST 49 0223 630B and Adapter ST49 UN11 101 to remove the LH axle bearing.
7. Use Converter Seal Remover ST 49 UN01 0870 or equivalent and Impact Slide Hammer ST 49 0223 630B and Adapter ST 49 UN11 101 to remove the RH axle shaft seal.
8. Use Bearing Remover ST 307-318 or equivalent and Impact Slide Hammer ST 49 0223 630B and Adapter ST 49 UN11 101 to remove the RH axle bearing.
Caution:
^ The matched numbers or letters stamped on both of the differential bearing caps and the axle housing must correspond upon assembly.
9. Remove the differential bearing caps.
1 Remove the four bolts.
2 Remove the two differential bearing caps.
Caution:
^ The ST bolts have a minimum thread engagement.
10. Install Spreader Adapters ST 49 UN01 027.
Note:
^ Make sure the indicator needle is in the spreader adapter hole.
11. Install Differential Housing Spreader ST 49 UN01 026 and Dial Indicator with Bracketry.
1 Install ST 49 UN01 026.
2 Install Dial Indicator with Bracketry and Clutch Housing Alignment Adapter ST 308-021.
Caution:
^ Over-spreading may cause damage to the axle housing.
12. Spread the axle housing.
1 Adjust the Dial Indicator to zero.
2 Tighten screw from Differential Housing Spreader ST49 UN01 026 until the axle housing is spread.
3 Remove Dial Indicator with Bracketry.
Caution:
^ Wood blocks must be used to avoid axle housing damage.
13. Remove the differential case from the axle housing.
1 Position the wood blocks.
2 Use two pry bars; push down on the pry bars.
3 Remove the differential case.
4 Remove Differential Housing Spreader ST 49 UN01 026.
14. Measure the pinion bearing preload.
^ Use a beam type torque wrench to measure the torque required to maintain rotation of the pinion and record the measure for reference during assembly.
15. Index mark the companion flange to the pinion stem.
16. Use Coupling Holder ST 205-126 to hold the companion flange while removing the pinion nut.
17. Use a 2-jaw puller to remove the companion flange.
Warning:
^ Gear teeth may have sharp edges. When handling gear, use care to avoid personal injury.
Caution:
^ Use a soft mallet to drive the pinion out of the axle housing.
18. Remove the pinion from the axle housing.
1 Hold the pinion inside the axle housing.
2 Use a soft face hammer to remove the pinion from the axle housing.
19. Use Converter Seal Remover ST 49 UN01 0870 or equivalent and Impact Slide Hammer ST 49 0223 630B and Adapter ST 49 UN11 101 to remove the pinion seal.
20. Remove the oil slinger (1) and the differential pinion bearing (2).
21. Remove the outer differential pinion bearing cup by tapping alternately on each side to prevent it from cocking in the bore.
22. Remove the inner differential pinion bearing cup by tapping alternately on each side to prevent it from cocking in the bore.
23. Remove the differential pinion bearing.
1 Install the Pinion Bearing Cone Remover 205055 or equivalent on the differential pinion bearing assembly.
2 Position the Pinion Bearing Cone Remover 205-055 or equivalent and the differential pinion bearing assembly in a press.
3 Press the differential pinion bearing off.
Note:
^ Measure the pinion position shim with a micrometer and record the thickness (use this as a reference to compare the shim gauge reading prior to installing the differential pinion bearing).
24. Remove the pinion position shim from the differential pinion gear.
25. Remove the ring gear.
1 Remove the eight bolts.
2 Use a drift punch to separate the ring gear from the differential case.
Assembly
Caution:
^ Before beginning assembly, perform/inspect the following: When assembling the axle, ALWAYS use new gaskets and seals.
^ All fasteners must be tightened to the torque specification indicated.
^ When building up the subassembly, lubricate each component with API Service GL-5. Also, lubricate the subassembly as it is installed into the axle housing.
^ Many components and surfaces in the axle are precision machined. Careful handling during disassembly, cleaning, inspection, and assembly can prevent unnecessary damage to machined surfaces.
^ Whenever the differential pinion bearing cups are replaced, the differential pinion bearing must be replaced.
1. Oil the new differential pinion bearing cups with axle lubricant meeting specification API Service GL-5 and install.
^ Use the Pinion Bearing Cup Replacer ST 49 UN01 035 to install the differential pinion bearing cups.
2. Install the original oil slinger and rear bearing onto the Middle Pinion ST 49 8531 565.
3. Install Collar Too] ST 49 8531 568 and O-ring to Middle Pinion ST 49 8531 565 and install them into the differential casing.
4. Install Collar ST 49 8531 567, yoke and washer.
5. Tighten the nut in Middle Pinion ST 49 8531 565 making sure the yoke can still be turned by hand.
6. Install Gauge Block (Front) ST 49 UN27 001 onto Middle Pinion ST 49 8531 565.
7. Place ST on a surface plate and set the dial indicator to zero.
8. Place Gauge Set ST 49 0727 570 on top of Gauge Block ST 49 UN27 001.
9. Place the pointer of the dial indicator so that it contacts where the side bearing is installed in the casing. Measure the lowest position on the left and right sides of the casing.
10. Add the right and left side measurements and divide by two to get the thickness dimension.
11. If not within specification, adjust the pinion height by selecting an oil slinger/selective shim which will bring the reading within specification.
Note:
^ It the drive pinion is marked with a plus reading, this amount must be subtracted from the thickness dimension.
If the drive pinion is marked with a minus reading, this amount must be added to the thickness dimension.
The rear bearing must be the exact same as the one used in the previous steps.
12. Measure the oil slinger/selective shim with a micrometer to verify the oil slinger/selective shim thickness.
Caution:
^ The same pinion bearing used in this procedure must be used in final assembly.
13. Install the pinion bearing.
1 Place the pinion position shim on the pinion.
2 Use Bearing Installer Set ST 49 F401 331 and Attachment C ST 49 F401 337A to press the differential pinion bearing until it is firmly seated on the pinion and pinion position shim.
14. Replace the collapsible spacer on the pinion stem.
Caution:
^ Installation without the proper tool can result in early seal failure. If the pinion seal becomes cocked during installation, remove it and install a new one.
Note:
^ The pinion sea[ must be fully seated all the way around or pinion seal damage can occur.
15. Install the differential pinion bearing and pinion seal.
1 Position the differential pinion bearing.
2 Position the oil slinger.
3 Position the pinion seal.
4 Use Pinion Seal Replacer ST 205-133 to install the pinion seal.
16. Position the pinion gear in the axle housing.
1 Apply a small amount of axle lubricant meeting specification API Service GL-5 to the pinion gear splines.
2 Position the pinion gear in the axle housing.
Caution:
^ The companion flange must never be hammered on or installed with power tools.
17. Align the index marks and position the companion flange.
18. Apply a small amount of lubricant to the washer side of the new pinion nut and install hand-tight.
Caution:
^ Never back off the pinion nut to reduce preload. If reduced preload Is required, Install a new collapsible spacer and pinion nut.
Note:
^ Pinion bearing preload is set by tightening the pinion nut.
19. Use Coupling Holder ST 205-126 to hold the companion flange while tightening the pinion nut to set preload.
1 Tighten the pinion nut, rotating the pinion occasionally to ensure the differential pinion bearings are seating properly. Take frequent preload readings until the desired reading is obtained by rotating the pinion with a Nm (inch-pound) torque wrench.
2 If the original recorded preload is lower than specification, tighten to specification, If the original recorded preload is higher than specification, tighten to original reading as recorded.
Caution:
^ Master bearings are marked LH and RH and must be Installed accordingly.
20. Remove the differential bearings and install the Master Bearing (LH) and the Master Bearing (RH) on the differential case.
21. Install the differential case with master bearings into the axle housing.
Note:
^ Repeat this step until a consistent reading is obtained.
22. Measure the total end play.
1 Position the Dial Indicator with Bracketry.
2 Position the indicator tip on the machined surface and adjust to measure full travel.
3 Push the differential case left and right (as far as possible).
4 Measure the total end play and record the reading on the Differential Bearing Shim Selection Procedure Worksheet, Line A.
23. Remove the differential case.
1 Remove the Dial Indicator with Bracketry.
2 Remove the differential case.
24. If burrs or nicks are detected on the ring gear mounting surface, use a fine flat file to remove them.
Note:
^ Do not reuse ring gear bolts.
25. Install the ring gear.
1 Position the ring gear and then start two or three ring gear bolts to align the holes in the ring gear and the differential case.
2 Use an appropriate press to install the ring gear.
26. Install the remaining ring gear bolts.
27. Position the differential case.
1 Install the Master Bearing (LH) and the Master Bearing (RH) on the differential case.
2 Position the differential case in the axle housing with the three missing bolts positioned down.
28. Position the Dial Indicator with Bracketry.
29. Push and rock the ring gear into mesh with the pinion gear (zero backlash) and set dial indicator to zero.
30. Move the ring gear away from the pinion gear as far as possible and record the reading on the Differential Bearing Shim Selection Procedure Worksheet, Line B in Step 34 of this procedure.
31. Remove the Dial Indicator with Bracketry.
32. Remove the differential case, the Master Bearing (LH), and the Master Bearing (RH).
Note:
^ Both of the differential bearing stand heights must be measured prior to installation on the differential case.
Note:
^ Mark the left and right differential bearings before measuring.
33. Clamp Bearing Preload Too[ ST 205S-337 base or equivalent in a soft-jawed vise with the bearing mounting surface above the surface of the vise.
34. Position the differential bearing assembly in Bearing Preload Tool ST 205S-337 or equivalent and tighten the tool.
35. Measure the differential bearing stand height.
1 Invert Bearing Preload Tool ST 205S-337 or equivalent and the bearing assembly in the vise.
2 Use a depth micrometer to measure and record the differential bearing stand height on the Differential Bearing Shim Selection Procedure Worksheet, Line D.
3 Repeat for the other bearing.
36. Select the appropriate differential bearing shims.
37. Install the differential bearings.
1 Position the appropriate differential bearing (RH or LH).
2 Use an appropriate press to install the differential bearing.
3 Repeat for the other differential bearing.
Note:
^ Make sure the indicator needle is in the spreader adapter hole.
38. Install the dial indicator with bracketry.
1 Install Spreader Adapter ST 49 UN01 026.
2 Install the Dial Indicator with Bracketry.
Caution:
^ Over-spreading can cause damage to the axle housing.
39. Spread the axle housing.
40. Remove the Dial Indicator with Bracketry.
Caution:
^ Never attempt to drive the differential bearing shims in place. The axle housing machined surfaces can be permanently damaged.
41. Position the differential bearing shims.
1 If removed, apply a light coating of axle lubricant meeting specification API Service GL-5 to one side of the differential bearing shims to help hold them in place.
2 Position the differential bearing shims.
Note:
^ Push the differential case down to fully seat the differential bearing cups in the axle housing.
42. Position the differential case.
1 Position the differential bearing cups on the differential bearings.
2 Lower the differential case in place between the differential bearing shims.
43. Install the bearing caps in their original positions and tighten with the axle housing still spread.
1 Position the differential bearing caps.
2 Install the four bolts.
44. Remove Spreader Adapter ST 49 UN01 026 and Differential Housing Spreader ST 49 UN01 027.
Note:
^ Measure the ring gear backlash at four places to obtain a consistent reading.
45. Measure the ring gear backlash.
1 Mount the dial indicator
2 Position the indicator needle and zero the indicator.
3 Turn the ring gear without turning the pinion gear and record the measurement.
^ If the backlash is not within specification, correct by increasing the thickness of one differential bearing shim and decreasing the thickness of the other differential bearing shim by the same amount.
46. Remove the Dial Indicator with Bracketry.
47. Rotate the differential case to ensure free rotation.
48. Use Axle Bearing Seal Installer ST 49 UN01 028 and Driver Handle ST 49 F027 003 to install the RH axle shaft bearing.
49. Use the Axle Seal Replacer 205-350 ST or equivalent and Driver Handle ST 49 F027 003 to install the RH axle shaft seal.
50. Use the Axle Bushing Replacer 205-347 or equivalent and Driver Handle ST 49 F027 003 to install the LH axle bearing.
51. Use the Axle Seal Replacer 205-350 ST or equivalent and Driver Handle ST 49 F027 003 to install the LH axle seal.
52. Install the axle shaft.
Caution:
^ Make sure the machined surfaces on both the axle housing and the differential cover are clean and free of lubricant before installing the new silicone sealant. The inside of the axle housing must be covered when cleaning the machined surface to prevent contamination.
53. Clean the gasket mating surface of the axle housing and the differential cover. Use silicone sealant.
Caution:
^ The differential cover must be installed within 15 minutes of application of the silicone, or new sealant must be applied. If possible, allow one hour before filling with lubricant to make sure the silicone sealant has properly cured.
54. Install the axle housing cover.
1 Position the axle housing cover.
2 Install the ten bolts.
55. Install the front axle assembly.
56. Fill the axle to specification with axle lubricant meeting specification API Service GL-5.