Rebuilding a Muncie M20 Transmission 4 Speed Gearbox

[@TargaWheels]

Thanks for the straight-forward instructions on disassembly and assembly. That's the first Muncie I've seen with rings on the input shaft. The three Muncie's I've had didn't have any rings. Good buy at $150. Down here you'd never find a Muncie cheaper than $400, and it won't come with a bell housing and a shifter assy.

[@1970chevelle396]

+TargaWheels If the input shaft has ever been replaced with an aftermarket one, it won't have the rings. Normally here you don't find them for $150. This guy bought it to convert his 72 Cutlass over but never did it. And the transmission had sat there for years. I really didn't want to buy it until he said $150. At that price I just had to buy it.

[@foowho8898]

Thanks for the video. If possible, I'd like to see you video how to do some of the reassembly. I'm new to these things and your video has helped me out but seeing how to actually assemble the parts would be great! Thanks again!!

[@1970chevelle396]

+Foo Who I'm not sure when I will have another one of those transmissions to do. Before I was using a Flip Video camera and they don't zoom out enough. Now I have a real video camera , so there will be a big improvement in my videos.

[@sinesiphomadikizela4350]

They were moving too fast while you putting together the different parts of the mainshaft

[@Thisoldcar]

Interesting video, I have never rebuilt a trans but have researched doing both manual and automatics. You did a great job showing and explaining what needs to be done. Thumbs up and cheers OLDDUDE

[@CruiserMac]

You make it look easy Ken, I wish they had KZbin when I was younger, we used to do things like that trial and error (mostly error) haha.

[@1970chevelle396]

Cruiser Mac There really not that hard to do. Especially after you have done a bunch of them.

[@rickboh]

Nice job Ken..i'v rebuilt a lot of cars & trucks from frame up in my time but never opened a transmission..i like seeing it being done

[@1970chevelle396]

rickboh I only do the manual transmissions. My Chevelle I've had everything apart at least once. I put every option in the car. Most of it I did back in the 90's.

[@265chevy]

You did a great job on the rebuild thanks for showing us now i can rebuild mine lol later

[@ziggassedup]

I like rebuilding those bear boxes...Shame that one had some tough areas due to rust.

[@1970chevelle396]

ZIGgassedUP I've done lots of them over the years. Here you don't see very many manual transmissions anymore. It seems like all the cars there selling now have automatics.

[@ziggassedup]

Once upon a time it cost for an automatic option and now it costs to get the manual option..Times have changed haven't they.

[@purestock22]

enjoyed the video... I see some similarities to the saginaw's and muncie 330

[@mexicanfrenchmenmoser7367]

How did you sbread the snap ring when you pressed on the midplate , from inside the case? to me that would be hard to do.

[@1970chevelle396]

jack moser when your putting that aluminum piece on there's enough room to get snap ring pliers in there. You only need to get it started over the bearing. Then it will just push on the rest of the way.

[@scottburns4515]

I've got to try to fix the speedo gear inside my 4sp trans. I believe it's a Saginaw 4sp. Is it possible to take the tailshaft off and fix this without taking the trans out of the car. My speedo gear will slide back and forth on the main shaft like the keeper is missing ir broke.

[@turbocobra]

interesting about the grooves signifying the ratio. Is that specific to Muncie, or are others the same? I know the manuals are easier to rebuild than an auto, but it's still way over my head... nice work Ken!

[@1970chevelle396]

turbocobra The Muncie's and the Borg Warner's have the grooves , that tell you what ratio they are. If you replace the input shaft with an aftermarket one . It won't have the grooves. I've rebuilt lots of the Muncie's and Borg Warner transmissions over the years. The last one I did was for a customer and I didn't have time to make a video on it.

[@mexicanfrenchmenmoser7367]

thankx i will try that i have built a few of these muncies always looking for some trick to make the job easier thankx

[@willmurphy9668]

yea

[@johnpalmer6566]

Awesome video. Ton of great info. I am replacing the 2 reverse gears on my m20. What is the best way to get the speedometer drive gear off? I only need to replace those gears and do not want to pull anything else apart. I am thinking a press is out of the question. Again thanks for the great video!

[@1970chevelle396]

+john palmer I used a great big Posi Lock puller to remove the speedometer gear.

[@erniehenshaw4161]

How did you figure the placement on the steel speedo gear on mainshaft.Great Video.

[@1970chevelle396]

You need to look at where it’s at on the shaft before you pull it off.

[@erniehenshaw4161]

@@1970chevelle396 Thank's

[@donaldmccall1276]

I just put an m20 on a 327 in a 61 vette chassis. Even in neutral the transmission stays engaged to the engine. Cant figure out why it wont disengage from the motor?

[@1970chevelle396]

Donald McCall Maybe when the side cover was put on the transmission one of the shifter forks didn’t go into the slider.

[@donaldmccall1276]

1970chevelle396 Im thinking the forks and sliders are too worn! I think I will do complete rebuild! Not that expensive. Thanks for the info!

[@wynnbost7276]

How did you clean all the parts?

[@michaelstump9828]

Is first gear lower in an m20 or m21.i have 396 with an m20 and 331 gears and I feel first gear should be much shorter.thank you.

[@1970chevelle396]

Yes first gear is lower in an M20

[@michaelstump9828]

Can a lower first gear be put in the transmission. Or should I lower rear end gears to something like 373s from 331s? Thanks again.

[@wtbm123]

Looking good

[@fiddlerpin]

That transmission has a 2:52 first gear not a 2:56 first like you say. 2:56 was in early m-20's

[@Buelligan88]

This would have taken me 5 days.

[@weeweed86]

Did you already sell this one.....? Where are you located....? I got a M20 that won't down shift from 3rd to 2nd or 2nd to 1st unless I'm at a dead stop or double clutch it. No grinding it just won't go in gear. Brian

[@1970chevelle396]

+weeweed86 I live in Northern California. I still have it. I haven't even tried to sell it yet.

[@265chevy]

i will buy the shifter and the rods i need them for my Muncie for the chevelle let me know

[@1970chevelle396]

265chevy I will send you the shifter free. The handle should be replaced. I wire wheeled the rust off of it. And one piece is missing where the rod attaches to the transmission. You can buy them from Hurst. Just e-mail me your address.

[@lickymywicky6289]

Awesome stuff thanks man.

[@fiddlerpin]

I would use the heavier spring in the side cover if I were you.

[@DriveShaftDrew]

great job

[@MrMuncieman]

Sorry Partner its not a 2:56 but it is a ....2:52 M-20 wide ratio. The 2:56 M-20 was only made from 1963-thru 1965

[@brenna2100]

Enjoyed your video , I've been doing Muncie's for over 50 years (yes I'm old ) but also good to see how others do them .We can away learn . I see you put the main shaft in before you but the pin in the cluster gear / I will try it your way .. Quick story / In the 70's I would flat tow my 70 SS LS6 to the track. One time towing on the highway first gear welded onto the main because of the no lube being thrown around. . The only thing moving is the main shaft. After all theses years I rebuild it and replaced the main shaft and first gear .. It was a M22 stone crusher ..PS My tow car was a 70 SS LS-5 // Like your 70 SS Ben

[@1970chevelle396]

The guy that taught me how to do them over 25 years ago always put the main shaft in first then the pin threw the cluster gear. He had 25 years of experience back then.

[@brenna2100]

Thanks for your reply , What do you do when the cluster gear wasn't needed to be removed . Sometimes pull the main shaft only to replace sync rings. would you still pull the cluster gear pin..

[@1970chevelle396]

brenna2100 Anytime I take one apart I take the whole thing apart. Even if your not going to replace everything its still a good idea to clean all the parts.

[@unclequack5445]

I need that bell housing did you sell any of this yet how much for the Muncie?

[@MrFireman164]

Thanks for sharing

[@midnightraiin4035]

are you anywhere near nys. i have a 5 speed,,nissan xterra,, thats destined for rebuild

[@1970chevelle396]

Midnight Raiin I live in Northern California.

[@midnightraiin4035]

thanks though

[@jebus3084]

🗿

[@RoddyDa]

Is $500 for an M22 a good buy?

[@1970chevelle396]

Thats a very good price

[@emoverrette9568]

Anybody trying to follow you is dizzy. Personally I don't think you have a clue about what your doing !

[@1970chevelle396]

emo verrette what do you mean I don't have a clue on what I'm doing? I've been doing this for 25 years.

[@emoverrette9568]

If you have been doing it for 25 years why did you put the speedo gear on when you did and why in hell would you put the mid plate bearing on first without the mid-plate ? If was to be a instruction video for guys it was terrible in my opinion. I have been building muncies for over 40 years and I would never assemble one looking so dirty or using rtv sealer. Another thing when you have a solid tube spacer like the 1 I saw in the vid you eliminate 2 rings because they are normally longer then the split 1's. If people want to watch good videos about Muncies they should watch Paul C. in gear box videos. If you going to teach be precise . You putting the cluster pin after you put the main shaft in is crazy ! How you going to check for clearance !!!! Maybe you don't do that ha ! I know 1 thing ! I wouldn't buy that transmission . Good luck !

[@emoverrette9568]

If you have been doing it for 25 years why did you put the speedo gear on when you did and why in hell would you put the mid plate bearing on first without the mid-plate ? If this was to be a instruction video for guys it was terrible in my opinion. I have been building muncies for over 40 years and I would never assemble one looking so dirty or using rtv sealer. Another thing when you have a solid tube spacer like the 1 I saw in the vid you eliminate 2 rings because they are normally longer then the split 1's. If people want to watch good videos about Muncies they should watch Paul C. in gear box videos. If you going to teach be precise . You putting the cluster pin after you put the main shaft in is crazy ! How you going to check for clearance !!!! Maybe you don't do that ha ! I know 1 thing ! I wouldn't buy that transmission . Good luck !

[@1970chevelle396]

emo verrette There is absolutely no way you've ever put one of these transmissions together before. You have to put the pin in the cluster shaft after you get the main shaft in. If you do it first you wont get the main shaft in. With the speedometer gear, I just accidently forgot about it. With the mid plate its easier to put it together the way I did. It takes all the rings on the cluster gear. If you leave two out there will be a gap there. I've done many of these transmissions over the years. I don't see your videos on rebuilding them. Its always the people that leave comments like this that don't have any videos to back up what there saying. It shows a pure lack of intelligence.

[@purestock22]

you arrogant ass... If you were all that you would know A. there's more than one way to skin a cat and B if you've never made a mistake you haven't worked on much. You don't have time to make a video but got time to be a critic...get outta here.