Usage:
768B (79S),
768C (02X),
772 (11S),
772B (64W),
776 (14H),
776B (6JC),
776C (2TK),
776D (5ER),
784B (5RK) Tractors;
771C (3BJ),
771D (6JR),
775B (7XJ),
775D (6KR) Quarry Trucks;
769C (01X),
769D (5TR),
773 (63G),
773B (63W),
773D (7ER),
777 (84A),
777B (4YC),
777C (4XJ),
777D (3PR),
785 (8GB),
785B (6HK),
789 (9ZC),
789B (7EK),
793 (3SJ),
793B (1HL),
793C (4AR) Off-Highway Trucks
Reference: Service Magazine Article; October 31, 1994; Page 7; "Wear Limits For Steering Linkage Ball Studs".
Description of Change: The horizontal wear limits for the ball studs and outer race bearings used in the steering linkage have been updated. While inspecting ball studs it is also recommended to inspect outer race bearings and lubrication seals. The "Planned Maintenance" and "Out of Service" wear limits have not changed. The inspection for steering linkage wear should be made every 1000 hours.
NOTE: This information should be recorded in applicable Operation And Maintenance Manual Modules.
The "Planned Maintenance" horizontal wear limit for ball stud and outer race bearing is 1.02 mm (.040 in). The "Out Of Service" limit is 1.27 mm (.050 in). The "Planned Maintenance" limit means that worn ball studs and outer race bearings should be replaced at the next regularly scheduled maintenance interval or when the machine is out of service for other repairs. The "Out Of Service" limit indicates that worn ball studs and outer race bearings must be replaced before the machine is put back into service.
Use the following method to measure horizontal ball stud and outer race bearing wear.
1. Attach the magnetic base of an 8T-5096 Dial Indicator Test Group to the link group (1) of the steering linkage so the horizontal movement of the ball stud can be measured.
NOTE: The horizontal wear limits on all ball studs and outer race bearings, including those on the steering cylinders, in the steering linkage should be checked.
2. Place the indicator against the side of the steering arm (2) or center arm (3) depending on which ball stud and outer race bearing is being inspected. Set the indicator dial to zero.
3. Turn the front wheels in both directions. Record the amount of horizontal play on the indicator dial.
4. If the steering linkage exceeds recommended wear limits, replace worn ball studs and outer race bearings. Inspect all ball stud covers, seals (boots) and grease fittings; replace if necessary.
NOTE: Steering linkage must be properly lubricated and free of contaminants to ensure component durability.
Steering linkage measurement locations.