I have a 69 SS 396 and just completed a rebuild of the Muncie M20. The car had a Hayes Competition clutch that chattered horrendously and required a gorilla left leg to operate. I had the GM 11" flywheel resurfaced and installed an AC Delco 11" clutch kit. Also replaced the Lakewood shift fork with a GM unit. The Muncie would pop out of third gear on deceleration and scratched going into 4th unless you paused. The Hurst Competition Plus shifter was also worn out and very sloppy so I bought just the shifter body and a metal bushing kit.

I've never had a 4 speed car prior to this one. All my previous Chevelles were 400 Turbos. Tore into this not knowing exactly what to expect. The Muncie tear down and rebuild was accomplished with parts from The Gear Box. Good people to deal with and fast service. Got a rebuild kit with counter shaft, Torque Lock sliders, Shift forks, and a new front bearing retainer. Took my time and followed the steps and pictures in an old Chevy Punch magazine article. Had to shim the cluster gear to get about .012" end play. If you have never attempted a Muncie rebuild, I highly recommend it. Absolutely doable for reasonable money if you are lucky, as I was, and didn't have to replace any gears.

While the car was apart, I pulled off the rusty headers and bead blasted them and repainted them with high heat paint. Relatively easy to remove by jacking up the driver side a few inches. One plus to this work was discovering the motor mount through bolts were 3/8" bolts rather than 7/16" as they should be. I am sure that these undersized bolts played a part in contributing to the clutch chatter.

Got it all back together today and took a drive. I am in heaven. Clutch is smooth, no chatter, and shifts like a dream. Well worth the effort and the car is more fun to drive. The clutch should be fine for street use and an occasional flog through the gears. Don't be afraid to dive into things you've never attempted before. Just take your time and use the search engine on this site for awesome tips and solutions. One great tip I got here was for removal of the pilot bushing. Used a 5/8" coarse thread tap to cut some threads in the bushing, screwed in a 5/8" x 2" bolt, and the bushing comes right out when the bolt bottoms on the crank. Slicker than snot on a door knob, but not as messy.

Ed:beers:

Ya can't go wrong with a Muncie. :beers:

I myself have yet to tear into a four speed. I have just driven them. I do have a T-10 I am going to rebuild, and I am going to buy a Super T that will at least need a bearing kit. I'm glad I know a lot of guys who still drive those four gears.

Hi Ed,
Is this the place?

http://www.thegearbox.org/home.html

I have a M20 to rebuild and will be giving these folks a call.

Yes, Prices are reasonable and good quality USA stuff. I had overlooked the condition of the bearing retainer during cleanup and found it was heavily worn right on top near the end. Ordered one from them and had it in 2 days. Only Japanese part was the standard front (8 ball) bearing. I reused the BCA 12 ball heavy duty bearing in the front. The box had been opened by someone before me and it did not appear to have many miles on the front bearing. I believe the heavy duty front bearing is a $34 upgrade, so not cheap. To shim the cluster and tighten the end play I used the old thrust washer on the reverse idler shaft (by the roll pin) and it worked out perfectly. The Chevy Punch article can be downloaded from their site. Feb. 2007 I think. Good luck.

Ed

I have a pretty good repair manual that covers rebuilding all the saginaw and muncie 3 and 4 speeds. It is in .pdf form. I would be happy to let someone host for download it if they have the means. I havent tried to email (although it might be possible) it as it is pretty large file 143megs. It covers everything you need to know.

I'm a do-it-yourselfer so I applaud you for tackling this yourself. :thumbsup:

I've rebuilt automatics but I haven't tried a manual tranny yet but I had planned to in the future.

Thanks for posting this because it encourages the rest of us to try it.