'63 Borg-Warner bearing retainer

[Michael Gill]

My '63 Coupe came orignially with a Borg-Warner transmission and 421 bell housing. I've sourced a late '62 B/W tranny but the bearing retainer is too large to pass through the 4 1/4" opening of the 421 bell housing. Does any one know the correct casting/part number for the smaller(in diameter) bearing retainer.
Regards,
Michael Gill

[Joe L.]

Re: '63 Borg-Warner bearing retainer

Michael-----

Unfortunately, the 1963 Borg-Warner T-10 used in Corvettes and passenger cars (except 409 cid) used a unique-to-63 front bearing retainer. This bearing retainer was machined from an aluminum casting. Originally, it was GM PART #3761931. It was last available under GM #604932, although I'm not sure if the later SERVICE part was made of aluminum or cast iron. The GM #604932 retainer was discontinued in July, 1984.

One ray of hope, though, is that this retainer was used for other applications. It was used for 1963 passenger cars and Corvettes with 3 speed transmission and it was used for some earlier series 10 trucks. I don't think that it's reproduced, but it may be by now.

[Wayne C.]

Re: '63 Borg-Warner bearing retainer

You might try this vendor to see if he can help:

http://www.oldmaneng.50megs.com

I read Joe's response about the 63 retainer being unique, but I think it also may have been used in 62 Corvettes, if not others... or, at least, I installed a '62 4-speed in a 63 to replace the original 3-speed many years ago and I don't recall having to chase after any extra parts. Is the bellhousing you have an original '63? (I don't know the correct casting number)... if you can't find the right retainer, perhaps you can find a bellhousing that has the right hole.

[Wayne C.]

addendum

Well, now I see that the 421 is the correct 63 bellhousing, so I can't explain how we got the 62 T10 into my car (it was done back in 63, so my bellhousing WAS original). I suppose it's possible we (my friend and I) switched the retainer with the 3-speed we removed, but frankly I don't think we were smart enough back then to even realize that could be done.

[Michael Gill]

Re: addendum

As with many posted questions various opinions arise. In sourcing out the correct size retainer it would be helpful to have a cast number to refer to when making inquiries. I've had one reply refer to it as a aluminum retainer with a cast number of 3790278 followed up with no GM cast number but with Borg-Warner using a number of T-10-107 embossed on the retainer. What to do here? Which info is correct??

[Tom P.]

Re: addendum

Michael:
The retainer from my Nov 62 original BW tranny is an aluminum piece with a base diameter of 4 and an eighth. It is cast "PT.NO.3790278" There is also a cast "GM" with a date code using several dots and a "62" There is a larger cast "S" with (perhaps) an "O" and "I" in the hooks of the S, followed by a "2". I assume this may be a manufacturers mark with shift information.

The weakness of this part is that it cracks at the base of the shaft.

Hope this helps. Regards.

[Franz E.]

[Michael Gill]

Re: '63 Borg-Warner bearing retainer

Thanks for your response Franz. I've checked the transmission and the number is T10-D1. It was cast November 21, 1962. It would appear correct for the car but has the wrong retainer of 4 5/8" diameter. My search now would be for a retainer of 4 1/8" diameter so that the transmission can be used with it's original 421 bell housing.

[Franz E.]

Re: '63 Borg-Warner bearing retainer

Hi Michael: The attaching bolts centerline, in the horizontal view, for the cast iron retainer is 2 7/8" with a 4 5/8" flange diameter (T10-1C). The centerline for the aluminum retainer is 2 1/2" with a 4 1/8" flange (T10D-1). The cast iron retainer will not bolt up to the T10D-1 main case bolt pattern without modifying either the main case or retainer. There remains possibility that Borg Warner released another cast iron retainer with the smaller bolt pattern and the larger flange diameter. On the inside of the retainer there should be Borg Warner part number. However, for all Corvette applications engineering released an aluminum retainer.