Peterbilt 379 / Cummins ISX etc. FAQs

How to adjust the clutch on a 379 Peterbilt?

Remove the access cover for the clutch, if applicable Bar the engine over with a barring tool, or by the alternator (not recommended), until you find a bolt head placed in the middle of a tab (this is the adjustment bolt) Place the correct socket onto the bolt with a ratchet, afterward, press on the ratchet with a pry bar in order to press the bolt head in and begin turning clockwise Begin with 1 full turn and check your adjustment Repeat steps 3 and 4 as necessary