Muncie Tranny Question
 

OK. I got my new rear axle housing installed with the new gears and carrier unit. Everything runs well. I did change the gears from 3.43 to 4.11s and now the speedo is correct at all speeds. Where as before it was off anywhere from 5 - 15mph. Question: wouldn't it make sense that if a Muncie 4-speed had a 4.11 speedo gear installed, (for the speedometer) that it would be a close-ratio 4-speed? I have yet to figure out if the tranny is a M20, M21 or M22. It does have a wine when I drive it but I have never heard a "true" M22 to compare it to. It almost sounds like a small blower when I am driving it...

Thanks - Rob

Re: Muncie Tranny Question
 

Does the trans have any letter codes on it? A,B, or C after the stamped number on the case?

Re: Muncie Tranny Question
 

No it doesn't. My car is a '68 and I believe they started putting letter designations on Muncie's in Oct. '68 for the '69 model year.

Re: Muncie Tranny Question
 

how many grooves on the input shaft? In general...
2 - m20
1 - m21
0 - m22

Re: Muncie Tranny Question
 

Can I see the input shaft without taking the transmission out of the car? Or the clutch?

Re: Muncie Tranny Question
 

Check and see if the trans has 2 pipe plugs in the case... one for fill and one lower to drain the case... if so it is a M22 case... no guarantee the straight cut gears are still in the trans, but the chances are better than not!

Re: Muncie Tranny Question
 

In 1970 model year and later all Muncie main cases got fill plugs and drain plugs, reguardless what the ratio... Crash

Re: Muncie Tranny Question
 

I know this is an old posting but I thought I would update you guys on what I found.

About 2 weeks ago the drive-shaft let go when I was going about 75mph - What a mess. It broke all four ears of the transmission including the bottom one where it not only broke the ear but cracked the whole bottom part of the case. I pulled the tranny and sure enough it had two lines on the input shaft - m20. The whine was probably from a bearing that must be bad. At any rate, the car is on jack stands again.

I plan on installing an Auto Gear case along with the heavy duty M22 gear set so I will eliminate another weak link of my drive-line....

The only thing that is left is the motor, and the guy who built that said that was bullet proof. Well, if he built the rear end or transmission like the motor, I'm in deep trouble!!

Re: Muncie Tranny Question
 

I don't know about '68s but our COPO Chevelle had the 4.10 gears and and M20 Muncie.