BEARING-THRUST 9U6877 - Caterpillar

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 "PS5394" 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.
This Revised Service Letter replaces the March 13, 1998 (Revised November 1999) Service Letter. Changes have been made to the TERMINATION DATE, Parts Needed, Service Claim Allowances, and Rework Procedure. Tractors previously reworked with the former Seal Gp. should NOT be further reworked unless a failure occurs.
Termination Date
December 31, 2000Problem
The rubber may separate from the midwheels on certain Challenger 35, 45 and 55 Tractors.
Affected Product
Model & Identification Number
35 (8DN1-881, 8DN897-920)
45 (1DR1-1767, 1DR1793-1896)
55 (7DM1-954, 7DM975-1256)
Parts Needed
12 - 5P9651 Cone-Roller12 - 5P9652 Cup-Roller12 - 1R1210 Wheel Assembly12 - 6S6031 Cup-Roller Bearing12 - 6S6032 Cone-Roller Bearing144 - 8T4779 Bolt144 - 9X8257 Washer12 - 6Y0925 Seal Group12 - 1390068 Hub12 - 1628462 SpacerAction Required
See the attached rework procedure.
Service Claim Allowances
This is an 12-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
Inspection and Replacement Criteria
The rubber will sometimes separate from the iron part of midwheels on Challenger 35, 45 and 55 Tractors. The separation normally starts at the inside flange of the midwheel (location A, Illustration 1 - the side of the midwheel which is next to the belt guides). It will progress down the ramp of the flange and then across the face of the midwheel until the rubber becomes completely separated from the midwheel. It is important to replace midwheels before the rubber becomes too loose, or comes off, because the flange will cut into the belt and cause damage to the structure of the belt. Tractors should be inspected for rubber separation. Use a screw driver, putty knife or similar tool to probe cracks in the rubber next to the flange (location B, Illustration 1). If the cracks are more than 15.88 mm (5/8 inch) deep all the way around the circumference, replace the midwheels. When one or more midwheels need to be replaced because of rubber separation, replace all twelve midwheels, since it is likely the others will fail soon.
1. Inspect tractor for rubber separation on midwheels according to the criteria above.2. If midwheels have failed, replace the old (1R1191) midwheels with new midwheels and hubs. Instructions for changing midwheels are in Disassembly and Assembly, Challenger 35, 45 and 55 Agricultural Tractors Power Train SENR8308 (Nov 95) Pages 27 through 31. (Note: Do not remove seal retainer, item 13 on Page 28).3. Using Illustration 2 and Table 1 as a guide, install the improved midwheel (1), spacer (10), hub (2), bearings (3)(4)(5)(6), seal (7), bolts (8) and washers (9).4. Torque the midwheel bolts (8) to 270 Nm (200 lb ft). As with any rework incorporating new Duo-Cone Seal Gps., once the installation is complete drive the tractor for ten minutes at less than 8 km/h (5 mph)