1957 283 pilot beariing

[John G.]

I am finishing a rebuild of a March 9, assembly late Feb. cast 1957 block engine. It has the original forged crank correct # and casting date close to engine casting date. Engine is assembled. Now assembling the clutch. The standard small block pilot bearing is loose in the receiver in the end of the crank. I think the standard bushing is 1.094. I think to fit my crank the OD needs to be about 1.105. What is the GM part number and specs to fit this crank. Was there a difference between manual and automatic transmission engine cranks in '57. I am running a Saginaw 3 speed. I think there was a pilot bearing in the crank when the engine went to the machine shop. I assume they took it out but did not put one back in and they are now having a problem finding the correct pilot bearing for the crank. The crank was good. I think they turned it down .010. I appreciate any input. Thanks. John

[Jim L.]

Re: 1957 283 pilot beariing

I am finishing a rebuild of a March 9, assembly late Feb. cast 1957 block engine. It has the original forged crank correct # and casting date close to engine casting date. Engine is assembled. Now assembling the clutch. The standard small block pilot bearing is loose in the receiver in the end of the crank. I think the standard bushing is 1.094. I think to fit my crank the OD needs to be about 1.105. What is the GM part number and specs to fit this crank. Was there a difference between manual and automatic transmission engine cranks in '57. I am running a Saginaw 3 speed. I think there was a pilot bearing in the crank when the engine went to the machine shop. I assume they took it out but did not put one back in and they are now having a problem finding the correct pilot bearing for the crank. The crank was good. I think they turned it down .010. I appreciate any input. Thanks. John

That's a definite "maybe".

I've never seen any difference in the machining between '57 cranks for/from PowerGlide engines and '57 cranks for/from std. transmission engines.

However, it's been my long held understanding that '57 cranks for/from TurboGlide engines were machined differently in the area for the pilot bushing. I've never knowingly seen a crank from a TurboGlide engine so I can't confirm this and I don't know what the difference was.

[David B.]

Re: 1957 283 pilot beariing

Crankshaft clutch Pilot bearing GRP.0.649 PN 412562 19/32 ID x 1 3/32 OD x 3/4 The '57 P & A catalog shows it was used on all manual trans eng. from 39-57. It is an original Oldsmobile part number.

[Thomas B.]

Re: 1957 283 pilot beariing

There certainly was in 1961 - but the auto is smaller than the manual - not the other way around. I did an engine swap from a '61 Impala, auto, rather naive at the time, assumed it was my problem getting the pilot bearing in, I finally gave up and turned it down. Later I learned that Dorman made a "conversion" Pilot bearing for just this use.

Still available

https://www.dormanproducts.com/p-18310-690-034.aspx

[Larry M.]

Re: 1957 283 pilot beariing

Autogear sells true Oillite bushings of various sizes, and will custom machine ones for you if needed. They currently show 5 different sizes for Chevrolet. They are an excellent source. Just Google the name for contact info.

Larry

[Ray K.]

Re: 1957 283 pilot beariing

The only crankshaft pilot bushing offered by Chevrolet was #3752487. My '69 P & A catalog shows usage for 1939 -69 with dimensions of 19/32" I. D., 1 & 3/32" O. D., and 3/4" length. This bushing was used for all manual transmission applications, 6 cyl and all V8. Automatic transmissions did not use a pilot bushing. Some crankshafts as originally produced used with automatic transmissions had a larger pilot bore diameter as compared to a crankshaft used with a manual transmission. This required sourcing a custom pilot bushing with a larger diameter in order to use a manual transmission.

Ray

[Gary C.]

Re: 1957 283 pilot beariing

Ray's correct according to the dozen or so '57 283 engines that were stamped standard transmission & power glides that I rebuilt over the years. Only had 1 turboglide and it was in a '57 red Nomad black interior with air conditioning that I owed in 1968.

Now, don't ask me how many I re-purposed from how they were originally stamped. LOL

Gary
....

[Mike M.]

Re: 1957 283 pilot beariing

is "re-purposed" synonymous with adding a second alpha to the suffix, as i'm unfamiliar with such pad modifications. Saint Michael

[Tom D.]

Re: 1957 283 pilot beariing

Several years ago, I had a crank with a smaller than normal bushing hole. I found THREE different versions from DORMAN. What you need is an OD just over 1 inch?

I found DORMAN "Powerglide Adapter" number 690-034 to be: .593 x 1.060 x .750.

Want one?