CYLINDER GP-STICK 2897933 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR REPLACING THE STUB SHAFT & BEARING AS. IN THE 4N1092 REAR BALANCER GROUP ON CERTAIN 631E, 637E, 657E SCRAPERS; 768C TRA CTORS; 769C TRUCKS; 3408 INDUSTRIAL, MARINE, SPARK-IGNITED, & GENERATOR SET ENGINES - PS4572 - MAILED US, CANADA, CACO, BRAZIL , CFEL, COSA, MARINE TEPS, LIMITED COFA
  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.
U-23 A-16 AU-12.1 B-3 E-19 O-22 TM-6 1220 PS4572 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 "PS4572" as Part Number, "7755" as Group Number, and "96" as Description Code. Termination Date
February 29, 1992
Problem
The surface finish of the stub shaft in the 4N1092 Rear Balancer Group of certain 631E, 637E, and 657E Scrapers; 768C Tractors; 769C Trucks; and 3408 Industrial, Marine, Spark-Ignited, and Generator Set Engines may not be as smooth as specifications require. A surface that is not smooth enough can reduce the service life of the bearing in the gear assembly.
Affected Product
Model Identification Number 631E 05A9833 1AB1385-1403, 1408 637E