C1 (1960) Transmission Case Swap - Can I do this?

[Donald H.]

I have a 4 speed transmission that I believe may be a 1961 T10. It has an aluminum main case and one person I spoke to said that 61s had cast iron main case and that I had a '62 tranny. However Nolan Adam's book says the switch to aluminum maincase was made early in the 61 production.

What I would like to do is find a 1960 cast iron main case and swap out the T10-1C with a T10-1B. Is there any reason I can't do this, other than finding a correct maincase?

The only casting markings I can find are in the Photos:

Maincase - T10-1C, and there are an F, 9 an S in circles

Tail case - T10-7B with date of 7 26 60

Thanks,
Don Harris

[William C.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Yes, the parts from your trans and a T-10 cast iron case will interchange with each other. If you are going to use a T-10 that did not come out of a Corvette in a corvette with the original (correct) Corvette transmission yoke, check the straightness of the splines on the mainshaft to make sure the Corvette yoke will fully seat onto the mainshaft. Many old T-10s develop a twist in the shaft due to heavy use and if found that will need to be repaired prior to use in a Corvette.

[Donald H.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Bill,

The car currently has a early '63 corvette T10D-1 transmission, which I was able to identify via an earlier posting on this forum.

I purchased the T10-1C as a more correct replacement. I plan to rebuild it and use with I get to restoring the chassis and drive train, which is next in line once I get the body off the frame.

Is it safe to assue that the current yoke in the car mated to the T10D-1 is correct for the T10-1C.

Since I am going to be rebuilding the T10-1C, should I be able to see any twisting in the splines when I have it apart?

Again thanks,

Don Harris

[William C.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Not knowing for sure what yoke you have on the driveshaft, the best thing to do is to just make sure the driveshaft will seat fully into the trans. If you truly have a T-10 1D in the car, what bellhousing do you have? The D series used the small front bearing and a one year only small diameter retainer. It will only mate to a '63 "421" bellhousing, and that bell does not have the mounting provisions for a '62 and earlier clutch arrangement, unless the front bearing retainer has been replaced with a cast iron unit from a truck that is sometimes used to "adapt" the '63 case to a "standard" bellhousing hole. As your '60 car used a 1-B iron case, the 1-C (61-62 only) is really no more correct than the one you have. If the one you have is working well, I'd be inclined to leave it alone until you find a 1-B case and build a trans from there.

[Stuart F.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Back in the day I broke a Cast Iron case on a T-10 (ears broke off due to lost drive shaft at 100+ mph in a 57 post Chevy). I replaced the case with an aluminum one, but recall one tailshaft bolt (or reverse section bolt) used a tapped hole into the cast iron case, and a clear through bolt with nut on the aluminum case. Perhaps someone can comment on this bolting aspect, not that it would affect your situation going the other way, other than maybe you will need one shorter bolt.

Stu Fox

[Donald H.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Bill,

I guess I need to wait and see what I have after I get the current transmission out of the car.

I had two earlier posts, one about the current T10D transmission and one about the bell housing. I think I have the correct bellhousing for 1960 according to the first post linked below:

https://www.forums.ncrs.org/showthre...78471&uid=9544

And this link is to the thread about identifying what transmission I have in the car:
https://www.forums.ncrs.org/showthre...78187&uid=2426

Thanks,

Don Harris

[William C.]

Re: C1 (1960) Transmission Case Swap - Can I do this?

Stu is correct, the intermediate plate is firmly attached to the iron case on early T-10's with a bolt using a very thin head, and as I recall a thinner gear on the reverse to clear the bolthead. I'd have to look thru some parts to recall what years, but I think it's only on the T-10 original and possibly the T10-1 designs, not the T10-1B used after '58.