Crankshaft pulley walked off a Cummins ISX on I-35 last Thursday

Had a 2018 Peterbilt come in with a weird vibration, thought it was a fan clutch. Got it up on the lift and the crankshaft pulley bolt had backed out almost half an inch, chewed up the keyway. What's the trick to keeping those bolts torqued on these engines without pulling the whole front cover?

2 comments

2 Comments

william_taylor4d ago

Oh man, I used to think factory torque specs were gospel on these ISX engines until I fought with three pulley walk-offs in six months. @alices16 nailed it with the new bolt and red Loctite combo, I started doing that after a 2015 T680 chewed through its keyway on a test drive. Have you ever tried running a cross-drilled safety wire through the bolt head and pulley hub for extra backup?

alices165d ago

Tell me about it man, I swear those ISX crank bolts have a mind of their own. We had a 2016 ProStar come in last month with the exact same deal - pulley was just wobbling around, the keyway looked like a chewed up pencil eraser. The trick I've found without pulling the front cover is to use a new bolt every time, plus a dab of red Loctite on the threads, and then hit it with a 3/4" impact that's been freshly calibrated. But even then you gotta check it again after the first 500 miles 'cause gravity just loves to play games with that assembly. Is it really that hard to add a tab washer from the factory on something that costs a small fortune to fix?