Pilot bearing?
Thread Starter
Teching In
Joined: May 2004
Posts: 40
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Pilot bearing? What would cause a pilot bearing on an LS1 T56 to wear out to a .015" wall sleeve or so almost to the point of wearing into the crank??? When I took the trans out I noticed the clutch disc wasnt centered with the pressure plate so I took a closer look down into the crank to find the pilot missing. After removing the clutch I found that the pilot bearing was there however it was just worn down to a thin sleeve that I could crack into pieces by squeezing it. Theres evidence of the clutch disc hitting the pressure plate and what triggered all of this was the slave cylinder being bad. The input shaft is marked up from hitting the slave cylinder (which broke in two pieces). The tip of the input shaft looks okay with a .586" diameter reading, the marks on the shaft portion are .998 (.001" deep scratches) from the original shaft size of 1.000". Could the pilot bearing just be worn that small after 150k miles (im guessing that it was never changed). I also forgot to mention the bellhousing had a crack in it but i'm not sure if this could be related.
Once the bearing fails and the rollers are gone, there's not much left to keep it from wearing down further. The prime consideration is your trans mainshaft bearings. If it's been run a long time without the pilot, you might have another problem. Make sure you check the mainshaft play.
