Transmission Pilot Bushing

[Dan White]

I am replacing the clutch in my 66 and would like to know if anyone knows what the best way to replace the pilot bushing in the crankshaft is. Since I have everything apart, I figured I may a well replace it...thanks in advance, Dan

[Steve Junkersfeld]

Re: Transmission Pilot Bushing

Dan, There is a tool that is made for that purpose. It is a small slide hammer that has expanding fingers on one end. The tool slides into the bushing, you turn the knurled nut to expand the fingers, a couple of slaps on the slide hammer and its out. You can probably rent or borrow one somewhere. Clean up the butt of the crank, make sure the new bushing doesn't have any burs on its outside surface (polish it up if it does) and tap it into the crank. I usually slide the bushing onto the input shaft of the transmission to ensure it fits well. When you re-install the transmission, a ltlle white grease on the inside lubes it. Steve

[Wayne P.]

Re: Transmission Pilot Bushing

You can do it with just a tap of the correct size to thread into the bushing. No need for a special tool.

[Terry M.]

Re: Transmission Pilot Bushing *TL*

Another method is to fill the cavity with grease and use a rod or bolt of the appropriate size (an old transmission input shaft works fine and it does double duty as a clutch alignment tool) to force the grease into the opening and the bushing will come right out. Bonus is no damage to the bushing, although I have to admit that is of dubious benefit if one intends to change it anyway.
Also consider using a roller bearing available from Chevrolet. It is listed in the High Performance (Power) book - my Power books are at some distance from the computer - I'll have to do like good ol' Mikey and put the computer in the garage. Original roller pilot bearing use is in diesel applications, but it will work fine in our gasoline engines. I recall Joe Lucia posting the part number some time ago, but any Chevrolet counter person of even modest skill should be able to find it.

[Joe L.]

Re: Transmission Pilot Bushing

Terry and Dan-----

The part number for the roller pilot bearing is GM #14061685. You won't find this number in any 53-82 Corvette P&A Catalog, though, nor is it supercessive to any part number in a 53-82 P&A Catalog. You will find it in later C4 P&A Catalogs, however, since it was OEM for some later C4 applications. It's also used for many truck applications, including diesel, going back quite awhile.

[Joe C.]

Re: Transmission Pilot Bushing

Terry:

I was of the impression that a permalubed bronze unit was the better choice for all but the most severe applications (where teardown/rebuild is not required on a regular basis).

Joe

[Craig S.]

Re: Transmission Pilot Bushing

Steve - Rimac makes a nice one of these....I have also used the method Terry mentions with the input shaft and grease...Craig

[Terry M.]

Re: Transmission Pilot Bushing *TL*

Joe,
I am sure that the roller pilot bearing is overkill in any but the most severe Corvette application, but I can't imagine why the bronze bushing would be superior. The only time the bushing/bearing should get any use is when the clutch is depressed. I would be interested in the observations and opinions of others, however, I may be overlooking something.

[Joe C.]

Re: Transmission Pilot Bushing

Terry:

With all due respect, I say this because there are no moving parts in the bronze bushing (bearing, if you will). The one piece unit would also seem to more positively locate the input shaft with the crankshaft. I was not advised to use a roller pilot bearing when I built my drivetrain, and so I would like to be convinced why a more complex design, with more moving parts, would be better. This is just "from the hip".

Why don't the engineers specify roller bearings for crank journals?

[Clem Z.]

Re: Transmission Pilot Bushing

since the roller bearing rollers runs directly on the input shaft you have to make sure that the shaft is smooth and pit free. using the roller with a new tranny is a good idea but check the input shaft if you use it with a used tranny. the torrington # is DB-50658 and make sure you put the inner shaft seal towards the tranny.

[Clem Z.]

most 2 strokes and some porshes use roller cranks *NM*

[Joe C.]

Re: most 2 strokes and some porshes use roller cra

Clem:

I didn't know that! I can say, however; that 2 stroke engines have very short longevity compared to four strokes, and so would require more frequent teardown/rebuild intervals. As for Porsches, well, all I can say is "Deutschland Uber Alles".
Joe

[Clem Z.]

Re: most 2 strokes and some porshes use roller cra

joe i can tell you from experience that installing a insert bearing in a chevy con rod is a lot easier than trying to install 32 loose needle bearing in a con rod in a 2 stroke chain saw engine.

[Dennis C.]

Re: Transmission Pilot Bushing

I will simply limit my input to - Use the needle bearing item... Dennis

[Joe C.]

Yeah! But What About The 7 Journals.............

on the sauerkraut engine.