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 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 "PS8555" 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.
Termination Date
December 31, 1996Problem
Early 3126 HEUI Engines in Magnum Chassis installations may have the wrong fan pulley and need to be replaced. In addition, full load and full torque settings (FLS/FTS) will need to be adjusted.
Affected Product
Model & Identification Number
Group 1
3126 (1WM511-1766 (for 250 HP Engine), 1WM601-1713 (for 300 HP Engines))
Group 2
3126 (1WM519-2366(for FLS/FTS adjustment))
Parts Needed
Action Required
1. Remove the fan belt, fan, and fan pulley.
2. Install the new 1253722 (for 250 HP Engines) or 1253723 (for 300 HP Engines) Fan Pulley.
3. Install the fan and fan belt.
NOTE: The 250 HP Engines utilize a 1:1 pulley ratio and the 300 HP Engines utilize a 1.15:1 pulley ratio.
4. Once the rework is complete, stamp the engine block with the letters "FP".
NOTE: The letters should be stamped on the rail located on the right side of the engine (turbocharger side), near the flywheel housing, five inches up from the oil pan mounting surface and four inches forward from the flywheel housing mount surface. Typically, the serial number is stamped on the horizontal surface of this rail. The letters "FP" should be stamped on the vertical surface.
Group 2
Adjust FLS/FTS per the attached chart.
Service Claim Allowances
If FLS/FTS is reset at the same time, add 0.5 hours (1901-510).
If ONLY FLS/FTS is performed, allow 1.0 hours (1901-510).
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
3126 Fuel Rate Adjustments, Magnum Motor Homes
