Loose Counter Weights Can Cause Banging Noise When Turning [TIBU3853]

FRAME AND BODY

COUNTERWEIGHT GP

Loose Counter Weights Can Cause Banging Noise When Turning

CONFIDENTIAL TIBU3853

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TECHNICAL INFORMATION BULLETIN	June 4, 2003
Wheel Dozers Landfill Compactors Wheel Loaders	834G (S/N: 6GZ1-Up, BPC1-Up) 836G (S/N: 7MZ1-Up, BRL1-Up) 988G (S/N: 2TW1-Up, BNH1-Up)
	Component Codes (7056)

SUBJECT: Loose Counter Weights Can Cause Banging Noise When Turning

PROBLEM: There have been field reports on 988G/836G/834G machines of noises such as a bang after changing steering directions. This can be caused by loose counterweight material in the rear bumper assembly. There are stacks (some vertical and some horizontal) of steel plates welded together and used as counterweight in eight different compartments in the 166-2833 Bumper Assembly. The counterweight plate welds can break and the plates shift while turning causing a banging noise in the rear bumper area.

The challenge is identifying which compartments have loose counterweights as a half of them are not visible and are inaccessible without cutting open the bumper. There are reports of loose plates in both the visible and "hidden" compartments. For reference, the eight compartments are described in following table:

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166-2833 Bumper Assembly Counterweight Compartments
Counterweight P/N	Location	View Access
197-6561	Right hand side under battery disconnect switch door	Open battery disconnect access door
197-6561	Left hand side under 192-8848 Plate Assembly	Remove bolt-on plate assembly
197-5376	Left hand side under 192-8848 Plate Assembly	Remove bolt-on plate assembly
197-5374	Center of bumper under radiator assembly	Look under radiator assembly or through four bolt access plate in bottom of bumper
132-9687	Outside right of rear tapered bottom section	No access1
132-9687	Inside right of rear tapered bottom section	No access1
132-9687	Inside left of rear tapered bottom section	No access1
132-9687	Outside left of rear tapered bottom section	No access1

1 - Access to this compartment can be made by cutting access holes in the bumper assembly under the 173-5986 & 173-5987 Tread plates. These counterweights consist of vertical plates welded into four compartments across the rear of the bumper.

SOLUTION: The following procedure is for the counterweights that have no viewing access.

Remove the 173-5986 and 173-5987 tread plates.

Cut access holes in the top of the rear bumper as shown in figure 1. Access holes should be made smaller than the tread plate area to cover repair welds.

Figure 1.

Weld 1/2" straps as needed to reinforce the counter weights and to ensure that the weights do not break loose again. Figure 2 is a picture of the left outer counter weight repair.

Figure 2.