VENT AS-AIR 3178685 - Caterpillar

Introduction
This Special Instruction provides instructions for the installation of the 129-6628 Speed/Timing Sensor on 3406E Engines.Note: This Special Instruction should only be used for 3406E Engines. The 129-6628 Speed/Timing Sensor is used on other engine models. The 3406E is the only model that uses the 126-8481 Washer .Do NOT perform any procedure that is outlined in this Special Instruction until the information is read and understood.Instructions
Use the following procedure in order to install the engine speed/timing sensor:
Extend the sliphead before you install the engine speed/timing sensor.
Check the position of the speed/timing wheel.Before the sensor is installed, ensure that the speed/timing wheel is in the correct position. The sliphead should not be allowed to fill one of the slots of the speed/timing wheel. Visually inspect the area with a flashlight.If it is necessary, turn the crankshaft in order to rotate the speed/timing wheel so that the sliphead is not allowed to fill the slot.Note: If the sliphead fills one of the slots in the speed/timing wheel, the sliphead will be broken off as the speed/timing wheel begins to rotate.
Install the sensor in order to set the sliphead into position. Tighten the sensor to a torque of 40 5 N m (30 4 lb ft).
Remove the sensor. Be careful not to bump the sliphead.
Place the 126-8481 Washer on the sensor.
Install the sensor and the washer. Be careful not to bump the sliphead. Tighten the sensor to a torque of 40 5 N m (30 4 lb ft).Note: The washer will prevent the sliphead from contacting the gear.
Follow the proper procedure for Engine Timing in order to calibrate.