Mystery Switch on 4 Speed Trans?

[Carr C.]

I'm are working on a 1973 454 Corvette with a 4 speed transmission. It has an electrical switch mounted in the 1-2 shift arm boss of the transmission side cover.

The switch has 1 black wire running to it that runs up to the firewall and into the interior.

Any ideas on what this is?

Thanks in advance!

[Patrick H.]

Re: Mystery Switch on 4 Speed Trans?

You sure it's the 1-2?

I would suggest that it's the 3-4, and it's part of the TCS system.

Patrick

[Wayne M.]

Re: Mystery Switch on 4 Speed Trans?

I'm are working on a 1973 454 Corvette with a 4 speed transmission. It has an electrical switch mounted in the 1-2 shift arm boss of the transmission side cover.

The switch has 1 black wire running to it that runs up to the firewall and into the interior. Any ideas on what this is ?

Carr (& Patrick) -- I'm not familiar with C3's, but I've seen a few Muncie side-covers with BOTH a switch on the 3-4 boss (like the '70-up 3952698 cover, AND another on an identical boss for the 1-2 shift. This latter cover has a unique cast part #, only 6 digits (like 3xxxxx). There was one on eBay a few weeks ago (should'a taken note).

So there was a need (maybe not Corvette) for a signal off the 1-2 shift position.

[Harmon C.]

Re: Mystery Switch on 4 Speed Trans?

You sure it's the 1-2?

I would suggest that it's the 3-4, and it's part of the TCS system.

Patrick

I agree

I had a 73 454 four speed and it had the TCS on the 3-4 and only was on in the 4 position.

[Wayne M.]

(Revisit) Mystery Switch on 4 Speed Trans?

I'm are working on a 1973 454 Corvette with a 4 speed transmission. It has an electrical switch mounted in the 1-2 shift arm boss of the transmission side cover.

The switch has 1 black wire running to it that runs up to the firewall and into the interior. Any ideas on what this is?

Carr & others who responded to his post a few months back.

From a recent eBay auction for some Muncie parts, including 2 sidecovers; the dirty 3952648 (switch on 3-4 shift arm) and another (clean) cover which I'd mentioned at the time, although I didn't have the part # or a pic back then. Shows here as 6-digit # 335308. This particular one does not have the 1-2 shift cast boss drilled, although I'd seen one with both 1-2 and 3-4 switches in place.
Probably '70-up usage, and unlikely Corvette.

[Joe L.]

Re: (Revisit) Mystery Switch on 4 Speed Trans?

Carr & others who responded to his post a few months back.

From a recent eBay auction for some Muncie parts, including 2 sidecovers; the dirty 3952648 (switch on 3-4 shift arm) and another (clean) cover which I'd mentioned at the time, although I didn't have the part # or a pic back then. Shows here as 6-digit # 335308. This particular one does not have the 1-2 shift cast boss drilled, although I'd seen one with both 1-2 and 3-4 switches in place.
Probably '70-up usage, and unlikely Corvette.

Wayne-----

I think the cover with the 2 switch BOSSES, one equipped with the TCS switch and the other unmachined, may have been used on some 73 and/or 74 Corvettes. However, the cover with both bosses machined for switch installation I do not think was a Chevrolet piece. The casting number was a Chevrolet part number because the Muncie was manufactured by Chevrolet. However, it was also used on Buick, Pontiac, and Oldsmobile. I suspect that the cover with both bosses machined was used for one of these other carlines and in the 73-74 period. It may have had a non-Chevrolet finished part number or it may have had a Chevrolet part number which was not used on any Chevrolet model.