GEAR (27 Teeth) 4D8542 - Caterpillar

The information supplied in this service letter may not be valid after the termination date of this program.Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
TERMINATION DATE
31May2010
PROBLEM
The existing engine to pump coupling can fail on certain 953D Track-Type Loaders. If the existing coupling fails, it will disconnect the hystat, implement and fan pumps from the engine. This will cause a loss of hydraulic pressure, causing the brakes to lock.
We do not expect to see failures below 1500 hours, therefore we recommend you perform the required rework in conjunction with other scheduled maintenance work.
AFFECTED PRODUCT
Model Identification Number
953D LBP00158, 166-173, 175-178, 180-368, 370-438
PARTS NEEDED
Qty
Part Number Description
1 1261420 SEAL-SHAFT
4 1902787 BOLT-SOCKET HEAD
1 2520235 COUPLING GP-BSC
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 9% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
ACTION REQUIRED
The original coupling needs to be replaced with the improved coupling. Refer to Disassembly and Assembly Manual, KENR5174, Pump Drive Coupling - Remove and Install. In addition, the premature wear of the original coupling might cause red dust to collect in the flywheel and pump housing. If this is the case, the red dust needs to be removed prior to re-assembly and the front hystat pump shaft seal needs to be replaced. Refere to Disassembly and Assembly Manual, KENR5174, Piston Pump (Hydrostatic) - Disassemble/Assemble - Left Side.
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SERVICE CLAIM ALLOWANCES
Product smu/age whichever comes first Caterpillar Dealer Suggested Customer Suggested
Parts % Labor Hrs% Parts % Labor Hrs% Parts % Labor Hrs%
0-4000 hrs,
0-60 mo 100.0% 100.0% 0.0% 0.0% 0.0% 0.0%
This is a 24.0-hour job
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.