Driveshaft Identification

[David B.]

Hello

I called the guy I bought the shaft from and he gave me a part number from a silver sticker that is on another shaft that he has. The number is 3921675. Anyone have any idea what it goes on?

Thanks Dave

[Joe L.]

Re: Driveshaft Identification

Dave-

GM #3921675 is a PRODUCTION-only part number which was used for 68-70 Corvette with THM-400, ALL 1971-75 Corvettes, and many 76-79 Corvettes. This part number is for the assembly which included driveshaft, u-joints, and transmission yoke. The assembly was never available in SERVICE from GM; only the component parts were available in SERVICE. However, I have seen these "silver tag with black-printed part number" pieces. I do not know the origin of them but I'm about 99.9% certain that it's not GM. It's actually illegal for anyone to put a GM part number on a part without GM's permission (e.g. the Restoration Parts Program). The law considers a part number to have proprietary standing, even if "GM" is not shown with the part number. A vendor can label a part as "REPLACES GM #XXXXXXX", though. Even the company that makes the pieces for GM (and, MANY Corvette parts were not made internally by GM divisions) cannot sell the identical part with a GM part number. In some cases, though, they can sell the identical part WITHOUT the GM part number if their contract with GM allows for it.

Anyway, I've seen driveshafts and half-shafts with these silver labels and GM part numbers, but I know not from whence they originate.