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 "PS8029" 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, 1994Problem
Low pressure from the transmission directional control valve on certain 416B, 426B, 428B, 436B and 438B Backhoe Loaders equipped with 4-wheel drive may prevent the directional clutches from being fully engaged. This partial engagement can result in failure of the directional clutch friction material.
Affected Product
Model & Identification Number
416B (8SG3308, 8SG3314-3315, 8SG3318, 8SG3322, 8SG3350, 8SG3354-3355, 8SG3358, 8SG3360-3362, 8SG3365, 8SG3366, 8SG3370-3374, 8SG3377-3378, 8SG3381)
426B (5YJ859, 5YJ861, 5YJ864-867, 5YJ869)
428B (7EJ1170, 7EJ1311, 7EJ1372, 7EJ1428, 7EJ1429, 7EJ1431, 7EJ1432, 7EJ1434-1435, 7EJ1437-1439, 7EJ1446-1447, 7EJ1450, 7EJ1452, 7EJ1463-1466, 7EJ1469-1470)
436B (6MJ401, 6MJ411, 6MJ413, 6MJ415)
438B (3KK673, 3KK676-677, 3KK679-682, 3KK684-688, 3KK691-692)
Parts Needed
Action Required
1. Remove the floor plates from the cab/platform.
2. Remove the linkage and disconnect the wiring harness to the control valve.
3. Remove the control valve retaining bolts.
4. Remove the existing transmission directional control valve.
5. Install a new 1096402 Control Valve Group using a new 1069860 Gasket.
6. Connect the wiring harness and install the linkage to the new control valve.
7. Replace the floor plates in the cab/platform.
Service Claim Allowances
NOTE: This is a 1-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling