M-21 input shaft

[Joe R.]

I've read here that the metal Muncie input shaft is helpful to have handy when mating up the tranny to the engine. For a L-72 with M-21, which input shaft do I need? Where can I get it?

Thanks,
Joe

[Timothy B.]

Re: M-21 input shaft

Joe,

Any GM course splined input shaft will work fine. A used shaft lines the disc better than any of those plastic tools.

[Tom P.]

Re: M-21 input shaft

I've read here that the metal Muncie input shaft is helpful to have handy when mating up the tranny to the engine. For a L-72 with M-21, which input shaft do I need? Where can I get it?

Thanks,
Joe

In the history of Chevy manual trannys, there have been only TWO types of input shafts: 10spline(coarse) and 26spline(fine).
The coarse spline trannys were used up through 1970 and the fine spline trannys began in 71.
You DO NOT need an input shaft from a Muncie to line up the clutch disc. ANY old junk tranny input shaft will work. For example if your Muncie is a 68 version, then a junk input shaft from a 55 Chevy 3sp will work just fine.

[Joe R.]

Re: M-21 input shaft

Tim and Tom,

Thanks for your help! Time to start searching eBay, junkyards and swap meets.

Joe

[Ray G.]

Re: M-21 input shaft

I've read here that the metal Muncie input shaft is helpful to have handy when mating up the tranny to the engine. For a L-72 with M-21, which input shaft do I need? Where can I get it?

Thanks,
Joe

Hello Joe;

In a pinch, we have used the transmission itself. Without the bell housing.
Support the trans. with a jack. Depends if your working in the Corvette or on an engine stand.

Regards.
Ray

[Timothy B.]

Re: M-21 input shaft

Joe,

If you trust your eyes, snug the pressure plate and center the disc by looking at the pilot hole and circumference around the pressure plate.