Usage:
NOTE: 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.
NOTE: This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS0600" as the Part Number and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use " Z" as the SIMS Description Code.
NOTE: This Revised Service Letter replaces the March 26, 1992 Service Letter. Changes have been made to the Termination Date and Parts Needed.
Termination Date
June 30, 1993Problem
There may be excessive wear in the retainer groove(s) of the pistons in certain 3406B Truck Engines.
Affected Product
Model & Identification Number
3406B (7FB1-UP; 8SB1-UP; 7XC1-UP; 8TC1-UP; 4MG1-UP; 5YG1-UP; 3ZJ1-6034; 5KJ1-7573; 2EK1-861; 4CK1-170)
Parts Needed
- *- 0R2413 Cylinder Kit
- *- 0R2694 Cylinder Kit
- *- 0R2861 Cylinder Kit
- *- 0R2862 Cylinder Kit
- *- 0R2974 Cylinder Kit
- *- 0R2975 Cylinder Kit
- *- 0R2694 Cylinder Kit
*Use as required.
Action Required
If the piston pin retainer groove has too much wear to allow for proper fit after the existing 8N7295 Retainer has been replaced with a new 7E5665 Retainer, replace the cylinder kit with the appropriate cylinder kit listed above.
Piston pin retainer groove wear is considered excessive when:
1. The piston pin cannot be slid out easily across either retainer groove due to metal displacement. It is normal for some pins to resist movement within the piston bores at room temperature. Clearances increase during engine operation.
2. The installation of the 7E5665 retainer does not provide a tight fit in the groove or rotates easily.
Whenever the piston is judged to be unusable due to piston retainer groove wear, replacement cylinder packs may be claimed against this Program. Pistons considered unusable due to wear unrelated to the piston pin retainer are not claimable under this program.
Service Claim Allowances
Parts Disposition
Cosa Dealers
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
All Other Dealers
Warranty claim parts that involve core credit must be held for 15 days after the Caterpillar Claim Register Date.