BOLT-FLANGE HEAD 8T4142 - Caterpillar

An engine speed/timing sensor is mounted in the flywheel housing. The speed/timing sensor provides information about engine speed and the position of the crankshaft to the ECM.
Illustration 1 g00760464
Remove engine speed/timing sensor (1). Inspect the condition of the end of the magnet. Look for signs of wear and contaminants.
Clean any debris from the face of the magnet.
Illustration 2 g01115363
Check the tension of the sliphead. Gently extend sliphead (2) for a minimum of 4 mm (0.16 inch). Then push back the sliphead. When the sliphead has the correct tension, at least 22 N (5 lb) of force is required to push in the sliphead from the extended position.
The sliphead must be fully extended when the speed/timing sensor is installed so that the sensor maintains the correct clearance with the speed-timing wheel. If the correct clearance is not maintained, the signal from the sensor will not be generated.Do not install the sensor between the teeth of the speed-timing wheel. Damage to the sensor would result. Before installing the sensor, ensure that a tooth of the wheel is visible in the mounting hole for the sensor.
Install the engine speed/timing sensor.
Ensure that a tooth on the speed-timing wheel is visible in the mounting hole for the sensor.
Extend sliphead (2) by a minimum of 4 mm (0.16 inch).
Coat the threads of the sensor with 4C-5597 Anti-Seize Compound. Note: The sliphead is designed to contact a tooth during the first revolution of the speed-timing wheel. For the maximum allowable clearance between the sliphead and the tooth, refer to the engine's Specifications manual.
Install the sensor. Tighten the locknut to 40 5 N m (30 4 lb ft).