General Items
| • | Thoroughly clean all parts with a suitable, clean solvent. |
| • | Oil the bearings immediately after cleaning and drying to prevent rust developing. |
| • | Inspect the parts for any major defects. |
| • | Clean the inside of the case before rebuilding and installing the parts, inspect individual parts as detailed next: |
Gears
| • | The pattern taken during the dismantling process should help in judging if the ring gear and pinion can be re-used. Worn gears cannot be rebuilt to correct a noisy condition. Gear scoring is the result of excessive shock loading or the use of an
incorrect lubricant. |
| • | Scored differential gears must be replaced. Examine the teeth and thrust surface of all differential gears. |
| • | Check the fit of the side gear hubs in the case. Wear on the hub of the side gear can cause a "clunking" noise when the vehicle is driven at low speeds. |
| • | Check that none of the thrust washers shows signs of wear, cracks or burrs. |
| • | Wear on splines, thrust surfaces, or thrust washers can contribute to excessive driveline backlash. |
| • | Inspect differential pinion gear bores and shaft surfaces for scoring. |
Bearing Cups
| • | Check bearing cups for rings, scores, galling or erratic wear patterns. For various roller bearing abnormal wear conditions and their causes, refer to Bearing Diagnosis in Final Drive and Driveshafts. |
| • | Pinion bearings cups must be solidly seated. Check by attempting to insert a 0.05 mm feeler between these cups and the bottom of their bores. Ensure that seating surfaces are clean and free from burrs or raised metal. |
Bearing Cone and Roller Assemblies
| • | The bearings in the differential case and the real (head) pinion should be checked before being removed from the differential case or pinion. If these bearing cup and cone assemblies are removed, they must be discarded and replaced with new parts. |
| • | When lightly oiled and rotated in their respective cups, bearing cone rollers must turn without roughness. Examine the roller ends for wear. Step-wear on the roller ends indicates the bearing preload was incorrect or the rollers were slightly misaligned.
Refer to
Bearing Diagnosis
in Final Drive and Driveshafts. |
Pinion Flange
| • | Check the flange mating face run-out. Refer to Specifications for the maximum Total Indicated Runout (TIR). |
| • | The end of the flange that contacts the bearing cone and the seal surface must be free from imperfections. |
| • | Check that the constant velocity (constant velocity) joint bolt threads are in good condition. Clean out any residual thread sealant by using an 8 mm tap. |
Carrier and Cover Housings
Check that the differential bearing bores are smooth and the differential carrier bearing preload spacer washer abutment faces are not damaged.
Differential Case
| • | Carefully examine the case for damage and ensure that bearing seating surfaces are free from dirt and burrs. The bearing assemblies will fail if they do not seat correctly against the shoulder on the housing. |
| • | The ring gear spigot and mating surfaces for the differential case halves should be clean and free from burrs. |
| • | Check that the differential pinion pin bores in the differential case are not oval. |
| • | Check that the mating surfaces for the two case halves are clean and free from burrs. |
| • | The differential side gear journal bores should be clean and free from scoring. The thrust surfaces for the differential case halves should be clean and free from burrs. |
