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Pulled the 4 spd trans in my 68 Cutlass for an unrelated issue, and noticed that the pilot bearing was laying loose behind the clutch. So, pulled the clutch and found out that while the bearing is snug inside the register of the crank, it is loose enough I can push it in and out w/ one finger. Went to the parts store to get a new bearing and green loctite (just in case the new one was loose too). Got home, and the new bearing is actually oversize on the ID and undersize on the OD compared to the old bearing. Test fitting on the input shaft it actually can rattle around a bit.
This is the first time I've messed w/ this kind of thing, and I only want to put it back together once. It occurred to me I might want to get a second opinion on what to do. I don't know if the crank is machined/worn oversize, if the bearings are both undersize, or even if I am using the right machined area in the crank for the bearing to go in. I would just measure the crank and shaft and order a bearing based on those, but I can't measure the crank because the area is too recessed for my caliper to reach.
Can someone confirm...
1. What the correct stock bearing dims are supposed to be?
2. Which register (deep or shallow) is supposed to be used for the bearing to seat in on the crank (see pic, deep is marked red, shallow is blue).
................New Bearing......... Old Bearing ..............Trans ................Crank
ID .............0.623" ......................0.593" ....................0.592"
OD ...........1.373" ......................1.376"...................... ........................... ??
According to a blueprint someone posted on this site, it appears the SECOND diameter in is the correct location. A dimension on the "print" shows 1.377", +.0005", -.0000" Do a test fit. I am guessing the bearing came out when you pulled the trans out
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Starting in 1970 the pilot bearing was held in with a snap ring, before that you had to stake the crankshaft around the bearing after installation. When I redid the clutch in my '68 I noticed the new bearing did seem a little loose in the crank but once I staked it the bearing it was fine. The pic from the service manual shows the bearing being staked just in one place but since my bearing also came out with the trans I staked it at 4 places around the crank.
Last edited by rob1960; September 3rd, 2018 at 04:10 AM.
It appears that your transmission is bottoming out in the crankshaft. It also appears that your crankshaft is not an original stick shift unit since its missing the last machined step where the input shaft is hitting the crankshaft.
September 2nd, 2018, 02:45 PM
