C1 ('62) Transmission Mount (to Frame) Spacer

[Christopher R.]

Finally getting around to installing a correct T10 in my 1962. With the Muncie in there, I needed to drop down the transmission crossmember to the frame a little over 1 inch (the thickness of 2 stacked lug nuts) so that the yoke and driveshaft wouldn't hit the underneath of the transmission tunnel. I know that many people replacing clutches on C1s report finding spacers in between the crossmember and the frame. Most usually report 1/4" to 5/8" thicknesses.

Corvette Central (CC) sells such spacers. But they're only about 1/8" thick. 1/8" doesn't seem like it'd be enough. CC also lists them for '62s only; and, only sells 2 to a set. I don't know why '62 would be different from other C1s; and, there are 4 mounting bolts for the crossmember. So maybe this isn't the solution. But it still seems that some spacers would be necessary. I'm requesting information on what other owners have done in this regard.

1. Did you need spacers?
2. What thickness?
3. Did you use 2 or 4 of them?
4. If 2, did you put them in the front, or in the back?
5. (Optional for extra credit: Can you think of something more elegant than lug nuts?)

[Mike E.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Chris--
My best answers to your questions are:
1) Yes--the factory put them there for 62 only, so you should have them
2) The factory-originals in my parts bin mic out at .152, and that includes non-factory rust. I suspect they are originally 1/8".
3) 2 of them--on on each side between the bottom of the top frame rail and the top of the crossmember. Each spacer has two holes--2x2+4 (the number of bolt holes in the frame and in the crossmember)
These are not there to keep the yoke and driveshaft away from the fiberglass--they are there to, in my understanding, provide the proper driveline angle for least vibration and wear on the yoke. Why only 62? My recollection, and I stand corrected if someone knows differently, is that the centerline of the crank on a 327 is 1/8" lower than on a 283 because of the longer stroke.
Hope this helps!

[Tom P.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Chris-Mike,
I have a VIRGIN 62 (in bad need of restoration, but virgin) in my shop. It has ONE 1/8in spacer on each side. There can be no question that the ENTIRE drivetrain on this 62 has NEVER been disturbed. Also, for the Muncie in my 56, I have a spacer on each side made from 1in square tube. Works perfect! I believe it's because the tranny mount on the tail housing of a Muncie is lower than the mount on the tail housing of a T-10.

[Ed Jennings]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Mike, that made sense when I first read it, but why would the CL of the crank change when the throws change? Keep in mind that I majored in sociology in college. Seems to me that the only way the crank CL would change is if the diameter of the mains changed. Maybe I'm just having a senior moment.

[Mike E.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Ed--
You're a sociology major--my major was in classical language--had to know Latin, Hebrew, Greek, and German in order to go into the ministry. I'd say that you're ahead of me!

[Ed Jennings]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Well, our mutual lack of engineering expertise not withstanding, is the crank CL on a 327 different from a 283? I, too wonder about the spacers. My 62 has a T10, but it isn't a 62 T10. It's an older CI case, so I'm not sure what sort of mouinting arrangement it has. I intend to look the next time I have it on a lift. The trans works fine and I have no intention of changing it, but I'd like to know what's supposed to be there if I do.

[Verle R.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

The centerline of all smallblock cranks is the same.

Different strokes are compensated for by rod length and wrist pin height in the piston.

Different main diameter is just larger holes in the block/main caps.

Verle

[John H.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

Adding spacers (washers) was covered in several Service Letters as early as 1957 to resolve driveline vibration issues (which resulted from the extreme C1 U-joint operating angles). My '57 (with a T-10) needed 1/8" of spacers (4 washers) so the front U-joint would clear the sheet metal guard up inside the tunnel, and I added another 1/8" to get a little more (total 1/4" at all four bolt locations); no vibration, no problems.

[Tom P.]

Re: C1 ('62) Transmission Mount (to Frame) Spacer

What Verle said. It doesn't matter if it is a 265 or a SB400.