SHEAVE "A" SEC 1C4327 - Caterpillar

Introduction
This procedure should be performed if the machine will not operate in specific gears. Step 1. Check system pressure.a. With the engine running at low idle and the parking brake disengaged, check system pressure at transmission main relief pressure tap (E).
Figure 1: Transmission Pressure Taps
(15) Transmission. (E) Transmission main relief. (L) Transmission lubrication. (M) Oil temperature. Expected Result: System pressure should be 2925 100 kPa (425 15 psi). Results:* OK - Proceed to Step 2.* NOT OK - Proceed to Step 3. Step 2. Check pressure.a. Start and run the engine at high idle and disengage the parking brake. Shift the transmission into a gear using the problem clutch.b. Measure the pressure for the clutch that will not engage.
Figure 2: ECPC Clutch Solenoid Valve Identification Expected Result: Clutch pressure is greater than 20 psi when engaged. Results:* OK - Proceed to Step 7.* NOT OK - Proceed to Step 4. Step 3. Perform Low Power Train Oil System Pressure. Results:* OK - Proceed to Step 5.* REPAIRED, OK - STOP. Step 4. Interchange valves.a. Interchange one of the clutch valves that should be engaged with one that should not be engaged.b. Verify whether the problem "follows" a particular valve.c. Repeat the procedure on all valves which should be affected during the problem speed and direction.See Figure 2: ECPC Clutch Solenoid Valve Identification Results:* FOLLOWS - Proceed to Step 5.* DOES NOT FOLLOW - Proceed to Step 6. Step 5. Check transmission modulating valve.a. Disassemble and inspect transmission modulating valve for the clutch that is not engaging.b. Repair or replace as required.c. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 7. Step 6. Restore valve.a. Restore all valves to their original locations, noting suspect valve and its original location.b. Check the operation of the machine for the original complaint.See Figure 2: ECPC Clutch Solenoid Valve Identification Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 7. Step 7. Inspect clutch.a. Disassemble and inspect clutch for failure.b. Check for excessive wear on discs and plates.c. Inspect the piston seals.d. Repair or replace as required.e. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - The cause of the problem is uncertain, please call technical support with the information gathered so far. STOP.