Usage:
776B ( 6JC ) Tractors;
777B ( 4YC ),
785 ( 8GB ),
789 ( 9ZC ) Trucks
Reference: Service Magazine; July 6, 1987; Page 1, "New Wheel Bearing Adjustment Procedures" on 785 and 789 Trucks.
The initial wheel bearing adjustment on 776B Tractors, 777B, 785, and 789 Tractors should be performed at the 2000 Hour Service Inspection. The second wheel bearing adjustment should be performed at the 6000 Hour Service Inspection. Wheel bearing adjustment intervals after the 6000 Hour Service Inspection, must be decided by the customer. The customer should determine the interval based upon information from the 2000 and 6000 Hour Service Inspections. When determining the adjustment interval, the customer should also consider any special applications and operating conditions that may influence the adjustment interval.
The large component sizes and the wear inherent from the "break-in" of those components can result in the loss of correct wheel bearing adjustment. Failure to maintain the correct wheel bearing adjustment can result in premature wear on the Duo-Cone seals, excessive wheel seal leakage, shortened wheel bearing life, and other damage. This could result in higher-than-normal repair costs for the customer.