3 Speed Trans For '56 Corvette

[Brooks G.]

Guys, I am trying to restore my '56 Corvette that I have owned since May 1967. The car was originally automatic but it has been a 3 speed since I have owned it. I would like to have a correct 3 speed transmission for it. Thus far I have not been able to locate such an animal. A buddy and I looked thru my assortment of trans parts and wonder if a correct one could be built from parts I have. I have a Corvette tail housing with part # 3787067 and a date of E - 20 - 6. I also have a main housing with part # 3743368 and a date G - 12 - ?. The year digit is not legible even with cleaning. All I can tell is that the digit is curved and could possibly be a (6). The housing also does not have a drain plug in the bottom. This main housing has a side cover with part # 3848594 and no date that I can find. Can anyone tell me about this assortment of parts? I have another Corvette transmission that I planned to take the gears out of to use if I can build a correct transmission out of these other parts. I know there has to be someone out there who is knowledgeable on '56 three speed transmissions. I thank you in advance!

[Joe L.]

Re: 3 Speed Trans For '56 Corvette

Guys, I am trying to restore my '56 Corvette that I have owned since May 1967. The car was originally automatic but it has been a 3 speed since I have owned it. I would like to have a correct 3 speed transmission for it. Thus far I have not been able to locate such an animal. A buddy and I looked thru my assortment of trans parts and wonder if a correct one could be built from parts I have. I have a Corvette tail housing with part # 3787067 and a date of E - 20 - 6. I also have a main housing with part # 3743368 and a date G - 12 - ?. The year digit is not legible even with cleaning. All I can tell is that the digit is curved and could possibly be a (6). The housing also does not have a drain plug in the bottom. This main housing has a side cover with part # 3848594 and no date that I can find. Can anyone tell me about this assortment of parts? I have another Corvette transmission that I planned to take the gears out of to use if I can build a correct transmission out of these other parts. I know there has to be someone out there who is knowledgeable on '56 three speed transmissions. I thank you in advance!

Brooks-----


The external components you need are as follows:

main case----GM casting #3845122

side cover----GM casting #3845157

bearing retainer ----GM casting #591620

extension housing----GM casting #3722946

The extension housing is Corvette-unique. The rest of the parts were common to passenger cars of the period.

The GM #3743368 main case you have is for 1958-63 Saginaw 3 speed applications. The GM #3787067 extension housing was used for 1961-62 Corvettes with Saginaw 3 speed. I believe your sidecover casting number is actually GM #3849534. It was originally used for 1964-65 Saginaw 3 speeds, Corvette and otherwise.

[Brooks G.]

Re: 3 Speed Trans For '56 Corvette

Thanks Joe, I guess I will keep looking for now.

[James G.]

Re: 3 Speed Trans For '56 Corvette

Ebay has produced many finds of these rare parts. Google the part numbers. Ask Roy Bratz, or Dave Fergusen on this forum. They may have one laying around.....or know where there is a unit.

[Steven B.]

Re: 3 Speed Trans For '56 Corvette

Brooks, I would also try The Driveline. I don't know much about Darrell Shepherd but he sells and rebuilds transmissons, rearends. He is connected with J. D. Piper.

Google 4 Speeds by Darrell

[Gary C.]

Re: 3 Speed Trans For '56 Corvette

Brooks, thought I'd sent to you previously. Attached is a list of 56-7 3 speed transmission parts and casting numbers. Gary....

[Brooks G.]

Re: 3 Speed Trans For '56 Corvette

Gary and Steven, thanks for your reply to my post. I have tried Darrell Shepherd with no results. I have called a number of other folks listed in the Driveline with no results either. Gary, the list of part numbers and casting numbers will be a big help. Thanks again!

[Edward M.]

Re: 3 Speed Trans For '56 Corvette

Brooks;

Start looking for a 56 passenger car three speed trans. If I understood Joe correctly, the external parts are the same except for the tail housing.

If that is correct, you need a 56 passenger car transmission for the main case, side cover, and bearing retainer.

Then you need the 56 Corvette tail housing.

The gear set you have in that old 60 Corvette trans should be the 2:20 ratio set that you need to build a correct 56 Corvette 3 speed trans.

Or maybe you get lucky and find somebody selling a 56 Corvette 3 speed transmission.

On another note, I located the 56 879 distributor that we talked about. It is yours if you want it. I can give you a good price on it.

[Steven B.]

Re: 3 Speed Trans For '56 Corvette

Gary and Steven, thanks for your reply to my post. I have tried Darrell Shepherd with no results. I have called a number of other folks listed in the Driveline with no results either. Gary, the list of part numbers and casting numbers will be a big help. Thanks again!

Brooks, just thought, have you tried Hemmings?

[Edward M.]

Re: 3 Speed Trans For '56 Corvette

Brooks, thought I'd sent to you previously. Attached is a list of 56-7 3 speed transmission parts and casting numbers. Gary....

Now that is good info. Thanks Gary and Joe.

[Gary C.]

Re: 3 Speed Trans For '56 Corvette

Ed, side covers are different. Passenger cars have bolt slots on top of the shifter arms to secure the shift arms and Corvettes have bolt slots on the bottom. Gary....

[Joseph T.]

Re: 3 Speed Trans For '56 Corvette

Guys, I am trying to restore my '56 Corvette that I have owned since May 1967. The car was originally automatic but it has been a 3 speed since I have owned it. I would like to have a correct 3 speed transmission for it. Thus far I have not been able to locate such an animal. A buddy and I looked thru my assortment of trans parts and wonder if a correct one could be built from parts I have. I have a Corvette tail housing with part # 3787067 and a date of E - 20 - 6. I also have a main housing with part # 3743368 and a date G - 12 - ?. The year digit is not legible even with cleaning. All I can tell is that the digit is curved and could possibly be a (6). The housing also does not have a drain plug in the bottom. This main housing has a side cover with part # 3848594 and no date that I can find. Can anyone tell me about this assortment of parts? I have another Corvette transmission that I planned to take the gears out of to use if I can build a correct transmission out of these other parts. I know there has to be someone out there who is knowledgeable on '56 three speed transmissions. I thank you in advance!

Have you checked your local salvage yards?

Chances are what you need is within driving distance and sitting on a salvage yard shelf.

Plus you may find other items while searching.

Joe

[Edward M.]

Re: 3 Speed Trans For '56 Corvette

Have you checked your local salvage yards?

Chances are what you need is within driving distance and sitting on a salvage yard shelf.

Plus you may find other items while searching.

Joe

Got one in mind. A Classic Chevy junk yard less than an hour away.

[Tyler T.]

Re: 3 Speed Trans For '56 Corvette

I have a complete 3 speed setup I took out of a 55. It has a 57 tailshaft but correct main case. It will be in the next driveline. Its everything from flywheel, to shifter, z bar, petal, and frame bracket.

Tyler