How to Adjust a Caterpillar D4 Clutch

by Nathan Fisher

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Synchronizing the rotational speed between the engine and transmission, a clutch operates by applying pressure against the engine flywheel and the transmission input shaft. Over time, as the clutch is continually put through repeated engagement cycles, wear occurs on the internal surfaces, resulting in play, or slack, in the mechanism. When operating heavy equipment weighing several tons, such as the Caterpillar D4 bulldozer, you must keep the clutch in proper adjustment to prevent it from wearing out prematurely.

Step 1

Remove the clutch housing cover, located on the bottom of the bulldozer, with a socket wrench.

Step 2

Locate the single 1/2-inch bolt securing the center of the spider gear assembly. Loosen the nut on the bolt with a wrench.

Step 3

Set a torque wrench to break or release at 30 foot-pounds of torque. Place the torque wrench on the clutch lever attachment bolt, connecting the spider gear to the clutch pedal.

Step 4

Tighten the spider bolt with a wrench, a quarter turn at a time. Test the pressure on the clutch lever with the torque wrench after each quarter turn of the spider bolt, until the torque wrench breaks at the 30 foot-pound setting.