I have a unique problem and several people have said there is an easy solution but I can not find it. Apparently I have a 283 crankshaft that was originally came in a powerglide car not a manual transmission car. The pilot bushing hole in the crank is several thousands too small to accept a standard GM small block pilot bushing. Several people have said there is a special bushing made for this application, but no parts house I have gone to has a clue what I am talking about. Has anyone else seen this problem and do you have a part number for this "conversion" pilot bushing? Thanks.
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Founder - Carolinas Chapter NCRS -
Re: Pilot Bushing - 1960 - 283
A 283 should take a pilot bushing, but if your right , have a machine shop mike the crank and cut the pilot down to fit???? -
Re: Pilot Bushing - 1960 - 283
I have a machined pilot bushing in it now and it just doesn't work correctly. If I didn't know better I would say that the outside of the bushing is hardened and when you machine it and install it it shrinks and becomes loose, which is the real problem I need to fix.Founder - Carolinas Chapter NCRSComment
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Re: Pilot Bushing - 1960 - 283
never seen this problem and the machine specs on the crank bore are + or - a couple of thou i would think. chevy never listed 2 different crank for std or auto trans cars.Comment
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Re: Pilot Bushing - 1960 - 283- Jimmy
Jimmy,
I hope this will be of help. I recently replaced my pilot bushing in my (originally) 265. It pulled it out (with slide hammer), extremely hard to get out. I miked the old bushing and the new one. The new one was around .008 bigger diameter than the old. I felt at that diameter I'd never get new on in. I machined down the diameter of the new bushing to the diameter of the old one. Even then it was a tight friction fit. Regards,Comment
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Re: Pilot Bushing - 1960 - 283
I have never heard of two different size pilot bushings, but if you were to buy the one that is applicable to the 1960 - 283 crankshaft, it is supposed to be tight. The only way that I have ever managed to get a bushing in the crankshaft without altering it was: first, after acquiring the bushing, go home and put it into the freezing compartment of your refrigerator, this will shrink the brass. I usually freeze it this way for a few hours. While the bushing is being frozen, clean and de-burr the pilot bushing hole in the crank and apply a very thin coat of white lithium grease in it. After all of this is done, very quickly while the bushing is still very cold, it can easily be tapped into the crank hole. I use the backside of a socket slightly smaller in diameter than the bushing, placed against the bushing and then tap on the socket until it bottoms out in the crank hole. To remove an old pilot bushing from a crankshaft, I pack the hole in the bushing with a heavy grease, then take an old junk pilot shaft and tap it into the pilot bushing hole. The grease will compress as you tap on the pilot shaft and this will drive the pilot bushing out of the hole. Many times I have used these methods of dealing with pilot bushings, and was succesful each time.Comment
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Re: Pilot Bushing - 1960 - 283
Jimmy, et al------
Here's the deal on pilot bushings for Chevrolet engines with manual transmissions, including Corvette:
1939 through 1957-----GM #412652
1958 through 1982-----GM #3752487
1983 through 2003-----GM #3752487 (sintered bronze), GM #10125896 (sintered bronze) or GM #14061685 (needle bearing type).
ALL of the above-referenced bushings are of 1-3/32" OD and are interchangeable.In Appreciation of John HinckleyComment
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Re: Pilot Bushing - 1960 - 283
If they're all the same size and interchangeable, why did Chevy have 5 different ones? OK, one of them is a roller bearing.
I raise the question, not because I expect an answer, but because of the next logical question. Are the later ones improved versions? Forgetting the roller one, if I were replacing one in my C1 today, which one would I want?Comment
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Re: Pilot Bushing - 1960 - 283
chris-----
There are numerous reasons that the part number could have changed over the years. A slight change in material or some minor spec change are 2 possible reasons, but I don't know what the actual reason was.
What's the best one of the 3 different sintered bronze bushings? In my opinion, it's GM #3752487.In Appreciation of John HinckleyComment
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Roy's right - Mike it and get the size;
go to a good machine shop/parts op and get the closest possible and machine to fit.Comment
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