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 "PS4467" as Part Number, "7755" as Group Number, and "96" as Description Code.
NOTE: Although this Program is to be administered as described above on the Affected Product, parts should be removed from parts stock as soon as possible.
Termination Date
May 31, 1991Problem
The torque convertor output shaft may fail on certain 631E and 637E Wheel Tractors due to torsional loading of the shaft.
Affected Product
Model & Identification Number & If Equipped WIth Torque Converter Identification Number
631E (1AB1-UP;1NB1-UP;3ND1-UP;3TE1-1205)
637E ( 1FB1-UP;1JB1-UP;3TE1-1205)
Parts Needed
- 1 - 1T1875 Shaft
Action Required
Parts Stock
Remove all 1T1592 and 1T1859 Shaft Assemblies from parts stock.
Affected Product
Install the new 1T1875 Shaft. Rework the existing 1T1594 Stator Carrier to the dimensions shown in Illustration 2. If excessive stator carrier damage after failure is encountered, install a new 1T1877 Stator Carrier along with the 1T1875 Shaft. Refer to the March 26, 1990 Service Magazine.
DO NOT install the new shaft assembly along with a former carrier that has not been reworked. Excessive restriction of torque converter oil flow would result. This would cause the torque converter to overheat.
Illustration 1. Location of components. (A) Enlarged bore in carrier. (B) Enlarged shaft diameter.
Illustration 2. Rework dimensions for former stator carrier.
Service Claim Allowances
Parts Stock
Submit one claim for all 1T1592 and 1T1859 Shaft Assemblies removed from parts stock.
Affected Product
NOTE: This is a 20-hour job.
NOTE: If there has been a previous repair, part age will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
Parts Disposition
Any parts removed (with the exception of cores used for Caterpillar Remanufactured parts) can be rendered useless and scrapped immediately upon completion of the repair.