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 "PS0574" 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.
Termination Date
December 31, 1992Problem
The speed timing sensor on certain Challenger 75 Tractors and 3176 Truck Engines may fail and cause the engine to stop.
Affected Product
Model & Identification Number
Challenger 75 (4CJ1-247)
3176 (2YG1-UP; 7LG1-1727)
Parts Needed
Action Required
Parts Stock
Remove all 9X4851, 9X5384, and 9X7870 Speed Timing Sensors from parts stock and render them useless.
Affected Product
If the cause of intermitent or complete engine shut down cannot be traced to the wiring, fuel system, engine protection system, or Electronic Control Module, replace the speed timing sensor with a 3E0487 Sensor and an 8L2786 O-Ring. Refer to the Electronic Troubleshooting module in the Service Manual. See Procedure P-221 "Engine Speed/Timing Signal Test."
Service Claim Allowances
Parts Stock
Submit one claim for all 9X4851, 9X5384 and 9X7870 Speed Timing Sensors removed from parts stock.
Affected Product
Challenger 75 Tractors
NOTE: This is a 1.5-hour job.
3176 Truck Engines
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.