4-speed Muncie trans
 

Hi,
A friend of mine bought this 68 Chevelle recently and is having trouble with the 4-speed in it. Does he have to get it out of the car to determine which trans he has, M20,M21 or M22? He wants to find a replacement first and then take it into the shop.
Stamped on the trans he found: P8E23 and 18W348416
Any help is appreciated.

https://www.yenko.net/ubbthreads/pics...314_151124.jpg

Re: 4-speed Muncie trans
 

Muncie from a 1968 Nova. I don't believe you can tell M20/21/22 in '68 unless you pull the trans and count the grooves on the input shaft (2=M20, 1=M21, 0=M22)

Re: 4-speed Muncie trans
 

You could also pull the side cover if you don't want to pull the whole trans.

Jason

Re: 4-speed Muncie trans
 

Drain plug?

Re: 4-speed Muncie trans
 

The M22 has the drain plug in the bottom of the transmission, don't believe 20 & 21 have a drain plug - only the fill plug in the right side.

Re: 4-speed Muncie trans
 

Exactly ... so that bit of info would thin the herd.

Re: 4-speed Muncie trans
 

a little bit of work but he could put it on jacks, pull the plugs and crank the engine over by hand in first gear and see how many revs it takes to get the driveshaft to go one full turn.

Re: 4-speed Muncie trans
 

You can try this method. Drive the car in 4th gear at 1000rpm and note the the speed. Now drive it the same speed in first gear and read the tach. If it's about 2200rpm, it's a close ratio. If it's about 2500rpm, it's a wide ratio.

Verne [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Re: 4-speed Muncie trans
 

I like Verne's method! Why didn't I think of that.

Re: 4-speed Muncie trans
 

Good call Verne. What I am curious about if he is having trouble with the trans, why doesn't he just pull it and have it gone through? There are lots of guys that are comfortable building Muncies. They are pretty simple.

Jason