Muncie rebuild thread

I wound up taking my recently acquired Muncie M20 apart to rebuild it. It's really amazing how easily this trans comes apart.

I watched a bunch of Paul Cangialosi's videos, watched his DVD and read his book. It literally took me 15 minutes to completely blow the trans apart.

There was one press operation. Once I removed the main shaft, aka the "shiskabob", I removed the front snap ring. The 3/4 hub just pulls off with third gear. I took the rear snap ring off and put a bearing splitter under second gear and pressed down from the tail of the main shaft. Once the second gear bushing pressed off, it dropped down to the speedo gear. So the reverse gear is used as a press plate for the speedo. And that was that.

I hit the counter shaft with a large punch and hammer. Came right out.

Honestly. The hardest part was cleaning the case and tail shaft. I'm going to post a step by step guide on putting it all together in the next coming week or two

 

I took the case, tail shaft, mid plate and side cover and cleaned the hell out of them. I used mineral spirits, brass brushes, and finally dawn power wash with a scrub brush.

After everything was scrubbed clean, I chased all the threads and used a file on all the gasket surfaces to make sure everything was flat. The file takes down any raised edges. You can see the results on the side cover. The shiny areas were "high"

 

Heading to D&L Transmissions next week to pick up the rebuild kit.

 

As long as your not in a rush. How many are we talking about?

 

Are you planning on beefing it up to maybe M22 or M23 territory?

 

I'd like to build this to go into a small block GS or Skylark down the road. So id like to keep it as a wide ratio. But we'll see what's available at D&L

 

Picked up parts yesterday. Bought a rebuild kit with the good synchro rings and the extended fit countershaft. Bought a pair of "zero rock" sliders, new reverse idler and new reverse gear. Everything purchased from Larry at D&L Transmissions. Super nice guy and has forgotten more about Muncies than most people know.




I brought the case with me and my "box o junk" for him to look over. He went through everything and told me what was good and bad. His keen eye picked up on some problems with my gear set.

Unfortunately, the input and cluster was no good. He pointed out that second gear was starting to come apart and the engagement teeth were a little worn on a couple. Larry has a really nice set of used GM M-20 gears he gave me a really good deal on so I bought them. They're as good as you can get as far as used gears go. They're literally like new.



Larry went through some rebuilding tips and tricks when I start to put it together. He was a wealth of knowledge. So we're all set to put this trans back together next weekend!

 

I'll be putting a couple of the sub assemblies together this weekend including the synchronizers. I'm going to test fit the gears to the synchronizers and make sure the keys dont drag on the rings. This is a good video on checking them before it all goes together