SUPPORT 3436309 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Bolts which secure the housing to the bevel gear, may loosen during operation on certain 797 Off-Highway Trucks.Solution
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
Inspections should be performed every 500 hours for sites and machines that have seen the bevel gear bolt loosening issue. For sites and machines that have not seen this failure mode, perform the inspection during differential oil change intervals or as needed. Refer to your machine Operation and Maintenance Manual for differential oil change intervals.Refer to Disassembly and Assembly, KENR8372, "Differential and Bevel Gear - Assemble" for information on how to assemble the differential and bevel gear.Refer to SMAG, M0067392 for corrective actions if bolts have backed out.
Table 1
Item Qty Part Number Description
H 40 515–8949 Bolt
Table 2
Required Tools
Item Qty Part
T1 1 Borescope
Illustration 1 g06276870
Location of bolts (H) within the differential
Illustration 2 g06278503
Rear view of differential carrier assembly
Remove 22 bolts (A) and 22 washers (B) that secure cover assembly (C) to differential carrier assembly (D). Retain the bolts and washers.
Remove cover assembly (C). Retain the cover assembly.
Remove O-ring seal (E) that is under cover assembly (C). Retain the O-ring seal.
Illustration 3 g06276868
Rear view of differential carrier assembly with cover assembly and part of differential carrier removed
Look inside to the left in the differential carrier assembly through opening (F) of the cover assembly. Inspect bevel gear (G) for the following problems using a flexible camera (T1):
Bevel gear bolts (H) backing out
Bevel gear and cage damageNote: Refer to SMAG, M0067392 for corrective actions if bolts have backed out.
Install O-ring seal (E) and cover assembly (C).
Install 22 bolts (A) and 22 washers (B) that secure cover assembly (C).
Tighten the bolts to the proper torque. Refer to SENR3130 , "Torque Specifications" for the proper torque.