DRIVE GP-FAN (BELT) 7L7431 - 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.
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 "PS8423" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
If rocker arms have already been replaced under another program, this Service Letter does not apply.
This Revised Service Letter replaces the July 12, 1995 Service Letter. Not all dealers will have received the July 12, 1995 Service Letter (-00). For those that have, changes have been made to the Affected Product, Action Required, and Service Claim Allowances.
Termination Date
January 31, 1996Problem
Some 1154190 Rocker Arm Assemblies used in certain 3116 and 3126 Truck Engines, 3126 Marine Engines and Challenger 55 Tractors may fail after a short time in service because they have a small cross section on the end opposite the adjusting screw.
Affected Product
Model & Identification Number
3116 Truck (9GK18331-28911 (Engine Arrangement 121-7766-only))
3126 Truck (1WM135-517)
3126 Marine (8NM355-611)
CH 55 (55K1-4, 55K25-28, 55K110-114)
All affected 3116 Truck Engines are installed in Ryder Trucks.
Parts Needed
1 - 1051542 Gasket12 - 1154190 Arm Assembly-Rocker (use only quantity needed)Action Required
1. Inspect the rocker arm assemblies for an adequate cross section and casting date code. The cross section is adequate if the milled surface for the "foot" does not extend more than 50% of the way through the web on the lower part of the rocker arm as shown in the Illustration below. Using a mirror, arms can be inspected without disassembly.2. Replace all rocker arms with a 4M22 casting date code regardless of cross section.3. See next page for engine ID.115-4190 Rocker Arm Assembly Stamp "GL" on the block at the rear of the engine information plate to signify this rework program has been completed.The engine information plate is located toward the rear of the block mid way between the oil pan and cylinder head.See Illustration 2.
Service Claim Allowances
3116 and 3126 Truck Engines
3126 Marine Engines
This is a 4-hour job. PI3777 does not apply to this product.
Challenger 55 Tractors
This is a 4-hour job. PI3777 does not apply to this product.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.