DIFFERENTIAL GP 4899965 - Caterpillar

Probable Cause
Valve ComponentsRecommended Actions
Complete the procedure in the order in which the steps are listed.
Table 1
Troubleshooting Test Steps    Values    Results    
1. Valve Components
A. Inspect the following components for damage:
1. Valve rotators
2. Spring locks
3. Valve springs
4. Valves
B. Ensure that the valve has not contacted the piston. If the valve has contacted the piston, check the exhaust system for debris.
   
Damaged Components    
Result: The valve components are damaged.
Repair: Replace the damaged components.
A valve rotator that is cracked or a valve rotator that is broken is an indication of an engine overspeed. Determine the cause of the engine overspeed. Repair the condition.