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Technical Muncie Tear Down, What’s Junk, What Can Be Reused?

Discussion in 'The Hokey Ass Message Board' started by lewk, Mar 11, 2023.

  1. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    I finally tore down the Muncie M20 I bought a year ago for my ‘60 El Camino. I got the Muncie, a rusty super T10, and most of a Hurst setup for a reasonable price from a guy who bought out tranny hoard and was selling it out. The M20 didn’t have a side cover or shift forks but he gave me some from the parts pile.


    I could tell from looking in the side cover hole that the synchros and sliders were a little rough.


    I got the tail shaft housing open. Reverse looks rough.

    I started finding chunks of metal. The 3/4 slider didn’t have any dogs in it and looked pretty rough.


    1/2 looked a little better and actually had its dogs.


    Rough brass.


    Cluster gear end surface is grooved.


    But the teeth seem OK


    Reverse again.


    Other gears and main drive gear





    To be continued…
    Last edited: Mar 11, 2023
  2. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    So I found 2 of the dogs, sort of…


    I did a basic clean up on the case and found some galling from debris.









    I didn’t see any cracking or structural kinda stuff. I have a lot of research to do, but I’m hoping I can reuse a fair amount of this trans. I know I need a kit, new slider assemblies, and reverse. Im hoping I can dress the surfaces on my case and reuse my other gears. I don’t know if my cluster gear is toast or if there’s a way to save that end.

    I’ve never been through a Muncie before and don’t know what I can get away with. This isn’t a perfect car, and it doesn’t need to be the ultimate trans. Im after functional. Any input would be appreciated!
    chryslerfan55 likes this.
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 55,729


    what a beauty.

    You can probably get away with using the cluster again. Might see if you can dress the points on the synchro teeth on the gears. But the main drive gear (which you call the input) appears to have steps worn on the sides of the synchro teeth, which might cause it to jump out of gear. Maybe, maybe not.

  4. lumpy 63
    Joined: Aug 2, 2010
    Posts: 2,602

    lumpy 63

    Thats a hurtin Muncie...

  5. 37gas
    Joined: May 25, 2013
    Posts: 143


    looks like a great mock up transmission to me
    Gasser 57, lewk and 427 sleeper like this.
  6. lumpy 63
    Joined: Aug 2, 2010
    Posts: 2,602

    lumpy 63

    I have used for rebuild kits , great service .
    Swede64, lewk, Russco and 5 others like this.
  7. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    I’ll dress the points on my gear synchro teeth and shitcan the main drive gear. I’m glad there’s hope for the cluster. Thoughts on the case, mid plate, and tail shaft housing?

    I appreciate the advise.
    Deuces and chryslerfan55 like this.
  8. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    I got it cheap enough that I have some space to throw some parts at it, within reason.

    I was watching his YouTube vids all morning. He’ll probably wind up with some of my money!
  9. wvenfield
    Joined: Nov 23, 2006
    Posts: 5,576


    I had to put a new main shaft, bearings, synchros, reverse and something else and it was still less money than I could find what I would trust as a good one for.
    lewk likes this.
  10. Beanscoot
    Joined: May 14, 2008
    Posts: 3,025


    The main body castings should be fine.
    I'm curious how you will dress the synchro teeth points. When I was an apprentice at the machine shop I spent a couple weeks in the cutter sharpening department so snuck in a couple gears and repointed the little teeth on the tool and cutter grinder, but it would seem to be pretty difficult by hand.
    These little teeth also become smaller as they are ground away to repoint them, but mine haven't failed me yet.

    I would also check your countershaft and matching bearings for wear or damage.
    Deuces, chryslerfan55 and lewk like this.
  11. SilverJimmy
    Joined: Dec 2, 2008
    Posts: 522


    Highly recommend, Paul’s a good dude and very knowledgeable. Every time I called, he answered the phone. You can probably send him your pictures and he’ll tell you what’s what.
    Deuces, chryslerfan55, lewk and 2 others like this.
  12. The cases will work out alright,,,,they can be cleaned and will work just fine,,,,no real damage .

    The slider assemblies need to be replaced as you have already realized .

    The reverse gears are horrible,,,,,,you could get away with just replacing the large gear,,,,,but it would be better to do them both .

    The cluster is okay to reuse ,,,,,,assuming the inside isn’t worn too bad where the needle bearings ride ?
    I have seen them wear in a bad pattern internally,,,,,check that good .

    The drive gears are fairly rough on the dog lug teeth,,,,,,a good cleaning and close inspection is needed .
    Some of them look really worn back,,,,,,they won’t give a lot of engagement area .
    These might still hop out of gear,,,,,even with new slider assemblies ?

    Of course,,,the brass is completely worn out,,,,and the transmission will definitely need a new small parts kit,,,,and large bearings as well ,,,,,,But,,,that’s usually normal anyway .

    You know what you have,,,,you seem to understand the importance of most of the components.
    It should require a fair amount of money and parts ,,,,,but ,,what doesn’t now a days,,,,lol .
    I hope the shafts look alright,,,,,it appears this transmission was run for some time with contaminated lube .
    Check the spline areas and the bearing surfaces of the main shaft too !

    Deuces, chryslerfan55, lewk and 3 others like this.
  13. SS327
    Joined: Sep 11, 2017
    Posts: 2,421


    Lewk when I rebuilt my m20 almost 15 years ago was where I got my parts. You may be better off buying new gears from them. Their rebuild kits were very complete and I upgraded to the steel mid plate at the same time. Either way your going to need a lot of parts.
    Deuces, lewk, Tow Truck Tom and 2 others like this.
  14. Tow Truck Tom
    Joined: Jul 3, 2018
    Posts: 1,833

    Tow Truck Tom
    from Clayton DE

    Glad you didn't pay too much.
    Good encouragements.
    As I look at the pics, I keep thinkin' "MACHO MACHO MAN!"
    Joined: Jun 3, 2005
    Posts: 10,205


    I've never been more than a scrub nurse on a trans rebuild. I'll be watching if this topic continues.
  16. Get his Muncie book, money well spent.
    Deuces, hrbhrb, lewk and 1 other person like this.
  17. I had mine done over locally in 2018. I missed 3rd gear at 5000 RPMs and blew the teeth off the main input gear and a few other things. I had already put an Auto Gear side cover on it in 2016. The guy I took it to was worth it. He was amazed that I said it generally shifted up and down pretty well.

    The reverse idler was trashed, someone cobbled it together. He used some good used parts and an Italian gear counter shaft since that was a goner. The counter shaft pin was a 7/8" and it floated back in the case, the key acted like a lathe bit and spot-faced an area of the mid-plate. He bored it for a 1" pin and it was a 2.56 1st gear, now it is a 2.52 ratio.

    My advice, price out an entire gear set from Auto Gear or Paul. I have no idea what the going price is. Oh now we do.. $725.

    I was on the fence with a new box when mine blew up. I was lucky to have it fixed right for a 1/4 of the price of a new one. Take a good look at the case, mid-plate, etc.
  18. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 2,831

    427 sleeper

    These things can be a bottomless pit when it comes to money and upgrades, just choose wisely. Depending on how much Torque you're throwing at this thing, an M-22 gearset and an Iron mid-plate might be a nice upgrade.
  19. justpassinthru
    Joined: Jul 23, 2010
    Posts: 524


    If that trans was on my bench, the majority of the internals would be scrap.
    I trim a lot of gears and those are beyond trimming.
    Both hubs have a lot of wear, can't really tell on the sliders.
    The cluster may be able to be cleaned up, but will have a lot of endplay.
    Case and tail look ok, but must check that cluster shaft fits right in the case, or it will have to be bushed, or it will be guaranteed to leak.
    Looks like some bolt holes have questionable threads and will need repair.
    Mid plate looks ok, but must check snap ring groove for wear, or the main shaft can walk.
    I'm my shop, time is money and the time spent attempting to trim the engaging teeth, with probably marginal quality and too much material removed, would exceed the cost for new quality gears.
    Id talk to Paul at 5 speeds if I were you.
    If you try to do a Muncie on the cheep, it will likely bite you back.

    Deuces, winr, chryslerfan55 and 4 others like this.
  20. justpassinthru
    Joined: Jul 23, 2010
    Posts: 524


    Go to and watch Paul's videos. (
    They are a treasure trove of information.
    You can get parts from him.

    Most part suppliers don't say who's parts they sell.

    Another good supplier that actually tells you the origin of the parts is:

    The best gear components are Italian stuff from Auto Gear.
    Second best stuff is Korean made.
    Then there is the crap from China.

    Only use Torq-Loc sliders, that are back cut, on a gear with back cut engaging teeth. (Korean)
    Use OE or Auto Gear sliders with straight cut engaging teeth, on an OE or Italian gear.
    Best not to mix and match gears.

    Good luck.

  21. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    I think I’ve watched 90% of Paul’s YouTube videos on Muncies at this point plus a couple randos. All were very helpful. The car is a low buck ‘60 ElCo that I’m trying to get on the road quick. It’s getting a vortec head 350. Everything is used and I’ll be lucky if I’m making 350 up. It’ll get a posi and relatively skinny tires. If I go down the rabbit hole of the best of everything and make it perfect, it’ll take me 10 years to finish the car and I’ll never drive it because I’ll be too worried about it. I know I’m playing in the shallow end of a deep swimming pool, but here we are. I’ve got a Vega Saginaw, a couple partial early T10s, the rusty Super T10, and this. $700 Italian gear sets are out, the best I can do is Taiwanese or used individual gears off eBay. I think the main shaft is usable. I haven’t measured the countershaft, but I can feel wear. It was snug in the case, for what it’s worth. I’m looking at the big rebuild kit, about $380, offshore gears, $400, reverse $80, and some hubs, whatever they cost. I got the box for $350/$400. Mystery Craigslist Muncies seem to go for $1200 to $1500 around here. The more I look at my existing gears, the worse I feel about them. More pics!

    558E4F2F-E137-4D1F-8F31-322CE37726C2.jpeg 3E31564F-27CB-43C4-AFBD-B031B192ED69.jpeg 11833BEF-FBAF-45B4-8959-31016345414E.jpeg 36101A8E-3859-47D4-A2A5-9D20984CCA01.jpeg E513BEFD-33ED-4FB9-BC3C-87432DBC8DD0.jpeg 950542CF-38C4-4A05-B419-C16C1D2CCB0C.jpeg E6406251-BCFA-4AAA-89D8-F0FE706712DF.jpeg CAEBAD2B-8302-4340-98FA-DBCE6E58D1D8.jpeg 7945B942-ACCD-481B-9BDA-51352C77E029.jpeg 9066806F-E83E-4434-A02F-44F8C5E03D70.jpeg 4E8ECEC4-E385-430F-963C-4F67E21645F1.jpeg 7FA94D82-739E-4033-8DA0-322905E873C1.jpeg

    I’m going to go out and try to pull the rusty Super T10 open and see how bad it is. Wish me luck!
    Deuces, chryslerfan55, SS327 and 2 others like this.
  22. it looks like someone was a habitual "reverse while moving still" shifter.
  23. justpassinthru
    Joined: Jul 23, 2010
    Posts: 524


    If it doesn't shift, grinds, or jumps out of gear, it doesn't matter if its going behind a 100HP engine or 600HP engine, it will do the same.
    Don't attempt to use those speed gears.

    Short of being broken, they are about as bad as bad can get.

    You would be better off looking for something else, or another Muncie parts core that you may be able to make 1 decent trans out of two.

    Deuces, chryslerfan55, SS327 and 3 others like this.
  24. larry k
    Joined: Feb 23, 2009
    Posts: 544

    larry k

    Man she is all used up !!! “Start lookin”
  25. I have rebuilt a lot of abused 4 speeds in my day but that one takes the cake (other than completely blown up).
    Deuces, SS327, bobss396 and 3 others like this.
  26. That Muncie must have sounded like a can of rocks rolling downhill. Hope the Super T10 checks out.
    Deuces, SS327, lewk and 1 other person like this.
  27. lewk
    Joined: Apr 8, 2011
    Posts: 1,008

    from Mt

    The rusty Super T10 was buried under my coupe. I drug it out and tore it down. It lived up to its name. I’ll still spend some time cleaning parts, but I’m not expecting much.

    53F0D7BF-7E19-4E0A-8662-4F129B25B144.jpeg 34FDFF38-A912-4B58-9F0F-721B15D9532B.jpeg C061F2B5-54AA-453C-A62F-EDAC14B061AD.jpeg E8DE6042-4401-4126-97E6-6D1BDDB74388.jpeg 1CC67431-5E48-4E72-9D9A-1B779829D517.jpeg 570608D4-58EF-4D72-89ED-55F993DCA9DF.jpeg 68791F4B-6E9E-485A-9563-A520EEC9E9C6.jpeg 213ED875-FDDD-4EB2-9336-751CD5C8559C.jpeg 503AD913-5603-418A-954A-0FB1C7E7100F.jpeg 0C037B99-C6D6-40E2-9EBC-17AFD84F6E63.jpeg
    Deuces, SS327, bobss396 and 2 others like this.
  28. DDDenny
    Joined: Feb 6, 2015
    Posts: 19,066

    from oregon

    All of the above, looks rode hard and rode hard again.
    Gonna be an expensive parts trans.
    Deuces, SS327 and lewk like this.
  29. Looks better than the Muncie already .

    Deuces, joel, ffr1222k and 2 others like this.
  30. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 2,831

    427 sleeper

    Even with all the rust and mung in there, it's still light year's ahead of the Muncie! It'll probably clean up nice with a little bit of bead blasting.
    Deuces, SS327, Desoto291Hemi and 3 others like this.

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