GEAR 2054587 - Caterpillar

Introduction
The trunnion supports on the Landfill Compactors, Soil Compactors, Wheel Dozers, and Wheel Loaders may develop cracks. The failures usually occur at high hours.The front and rear trunnion supports on the rear oscillating axle may develop cracks or the bolts may become loose if the rear frame mounts are not parallel. This can be a problem if the rear frame is cracked or if the rear frame was previously repaired.Inspect the trunnion supports, bolts, and the rear frame for cracks during routine machine maintenance. This inspection is recommended even if cracks to the rear frame were repaired previously. Cracks in the trunnion support are most likely to start at the top of the support beam next to the frame or between the mounting bolts. If cracks are present do not attempt to repair the cracks by welding. Replace the cracked trunnion support.If cracks are found in the rear frame and the cracks are not repaired the trunnion support will crack. Engine damage is possible if the trunnion support fails. Refer to any separate Caterpillar literature for repair of cracks to the rear frame or contact Caterpillar Product Support for assistance.Check Trunnion Mounting Plates
There are two methods in order to check parallel of the trunnion plates. One method involves using a straight edge. The other method is using the trunnion supports.
Ensure that the trunnion mounting plates are parallel from one side to the other side. Use a straight edge in order to visually check if the mounting plates are parallel or you can install the trunnion support.
When the trunnion support is used to check parallel, install two bolts per side. The bolts should be at each outside corner. Tighten the bolts to 100 N m (74 lb ft). This will position the support in contact with the mounting plate.
When the straight edge is used to check parallel, check several locations over the full length of the mounting plate. Use a feeler gauge or an appropriate measuring tool in order to measure any gaps between the mounting plate and the trunnion support. Also check between the mounting plate and the straight edge. If the gaps are larger than 1 mm (0.04 inch) the gap must be reworked until the gap is less than 1 mm (0.04 inch).
If the mounting plates are not parallel the trunnion support and the mounting bolts will be in bending stress. Additional failures in the trunnion support, in trunnion mounting bolts, or in the rear frame may occur.The following Table shows the part numbers for the trunnion supports of the affected machines.
Table 1
    Trunnion Support    
Model     Serial Number     Front     Rear    
826G II
836G     (S/N: AYH)
(S/N: BRL)     105-8704
164-2752     105-8703
164-2751    
825G II     (S/N: AXB)     105-8704     105-8703    
824G II
834G
844
854G     (S/N: AWW)
(S/N: BPC)
(S/N: BBN)
(S/N: AMP)     105-8704
164-2752
4E-3095
235-8668     105-8703
164-2751
4E-3096
6W-6368    
988G
990 II
992G
994
994D     (S/N: BNH)
(S/N: BCR)
(S/N: AZX)
(S/N: 9YF)
(S/N: 3TZ)     164-2752
4E-3095
235-8668
165-4014
165-4014     164-2751
4E-3096
6W-6368
165-4015
165-4015