SEAL GP-CRANKSHAFT 1878964 - Caterpillar

Magnetic Pickup Verify
1. Connect a 6V7070 Multimeter (or a voltmeter of same accuracy) to electronic speed switch common terminal (ESS-3) and signal terminal (ESS-4). Set the meter voltage scale to a scale greater than 1.5 VAC. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, the operation of the magnetic pickup is correct. If measured voltage is less than 1.5 VAC, go to Step 2.2. Disconnect the wiring from the magnetic pickup and connect the voltmeter to magnetic pickup connector terminals 1 and 2. Set the voltmeter voltage scale to a scale greater than 1.5 VAC. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, repair or replace the wiring between the magnetic pickup and the electronic speed switch. If the measured voltage is less than 1.5 VAC, go to Step 3.
MAGNETIC PICKUP
1. Clearance dimension. 2. Magnetic pickup. 3. Wires. 4. Locknut. 5. Gear tooth. 6. Housing.3. Remove magnetic pickup (2) from the engine flywheel housing (earlier location, front drive housing) and turn the flywheel until a gear tooth (5) is directly in the center of the threaded opening for the magnetic pickup. Install the magnetic pickup again in the threads of housing (6).By hand, turn in a clockwise direction until the end of the magnetic pickup just makes contact with the gear tooth (5). Now turn the magnetic pickup back out 1/2 turn (180° in the counterclockwise direction) to get the correct air gap [clearance dimension (1)]. Now tighten locknut (4) to a torque of 68 13 N m (50 10 lb. ft.). Do not let the magnetic pickup turn while locknut is tightened.Do Step 2 again. If voltage is still less than 1.5 VAC, replace the magnetic pickup.