PUMP GP-PISTON 10R2520 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR FINAL DRIVE RING GEAR AND RETAINER RING FAILURES ON D6H TRACTORS - PS4157 - MAILED US AND CANADA, CACO, COSA
  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.
PRODUCT SUPPORT PROGRAM FOR FINAL DRIVE RING GEAR AND RETAINER RING FAILURES ON D6H TRACTORS, 4084, PS4157 U-86 A-35 O-43 This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4157" as Part Number and "7755" as Group Number. Termination Date
June 30, 1989
Problem
The groove in the final drive ring gear and the retainer ring do not fit correctly on some D6H Tractors. This can result in the retainer ring working its way out of the groove in the ring gear.
Affected Product
Model Identification Number D6H 4RC1 - 1079 7PC1 - 688 8YC1 - 477
Parts Needed
Before Failure - per side 1 - 9H3360 Seal (as needed) 1 - 6V3248 Seal (as needed) 1 - 1P9005 Seal (as needed) 1 - fabricated plate After Failure - per side 1 - 8G8844 Ring 1 - 6V3248 Seal 1 - 9G8639 Gear 1 - 9G5343 Seal Group (as needed) 1 - 9G8640 Hub (as needed) 1 - 9H3360 Seal (as needed) 1 - 1P9005 Seal (as needed) 1 - 6V327 Cup (as needed) 1 - 6V328 Cone (as needed) 1 - 6V329 Cone (as needed) 1 - 6V330 Cup (as needed)
Action Required
Both final drives should be repaired at the same time. If the repair is after failure, only the side that has failed should be repaired as an "after failure". The other side should be repaired as a "before failure". Before Failure Fabricate a plate from mild steel according to the dimensions in Illustration 1. One plate will be needed for each side that is repaired before failure. Remove the ring gear, hub and retainer ring as a unit using the "Final Drive Planetary Carriers (In Chassis)" procedure in the Service Manual. Ensure that the ring is installed as deep as possible in the groove of the ring gear. Weld the plate in position as shown in Illustration 2 using E7018 Electrode. Install the parts. Illustration 1 (SEE ILLUSTRATION) Illustration 2 (SEE ILLUSTRATION) After Failure Remove the ring gear, hub and retainer ring using the "Final Drive Planetary Carriers (In Chassis)" procedure in the Service Manual. Install the new gear and ring. Ensure that the ring is installed as deep as possible in the groove of the ring gear. Install the parts. WARRANTY