[HawkX66]

I have a '73 M21 from a Z28 that I'm getting ready to R&R. I'd rather not disassemble the main shaft/gears & synchros if I don't have to, but I want to replace all the seals and gaskets. Anything I should be watching out for? How do my gears and synchros look? They seem good to me.
It was tight at first, but when I removed my side cover & shift forks the input shaft had a little play in it. Is that normal or do I need a new bearing or something else?
I'd like to buy a gasket/seal kit. Any suggestions on a good reasonable source? Also, other than making the aluminum look nice, does everyone paint them with cast aluminum or just leave them natural? She's a dirty girl. I plan on soaking it with Simple green and gas, then washing it with soap and water. Hopefully that will be enough.

Thanks.

 

[tangobravo]

Check Paul Cangialosi's Muncie 4 speed videos here: https://www.youtube.com/channel/UCxP2351joupD-Re3KFpDTNQ He puts together the best rebuild kits at a great price on his 5Speeds Transmission Home Page website. Have a look at his book too.

 

[grampstoyz]

I have recently done business with Jody's Transmission. He has quality parts and good advice.

 

[HawkX66]

Thanks guys. I'll check out those vids. Yes, I've seen Jody out here quite a bit. Good rep. It looks like all I need is a $15 gasket and seal kit. Hopefully...

 

[zman1969]

I have recently done business with Jody's Transmission. He has quality parts and good advice.

X2 on Jody :thumbsup:

 

[COPO]

Look at the gears and cluster gears on my website here Muncie at the bottom of the page and make sure you have a good arrow head shape on the gears where it slides into the slider. Same goes for the slider. I show new and worn gears and sliders here when I rebuilt my M22.

 

[Luwi67]

Thanks Mark, just bookmarked that site.

 

[1971ls6]

Degrease it and scrub it with a scotch brite pad. Paint always looks like paint.

 

[JodysTransmissions]

I have a '73 M21 from a Z28 that I'm getting ready to R&R. I'd rather not disassemble the main shaft/gears & synchros if I don't have to, but I want to replace all the seals and gaskets. Anything I should be watching out for? How do my gears and synchros look? They seem good to me.
It was tight at first, but when I removed my side cover & shift forks the input shaft had a little play in it. Is that normal or do I need a new bearing or something else?
I'd like to buy a gasket/seal kit. Any suggestions on a good reasonable source? Also, other than making the aluminum look nice, does everyone paint them with cast aluminum or just leave them natural? She's a dirty girl. I plan on soaking it with Simple green and gas, then washing it with soap and water. Hopefully that will be enough.

Thanks.

You should use the 20lb detent spring upgrade for your sidecover. Your M21 looks great, but you should get it apart to actually see what is needed.

You will have to measure the synchronizer clearance on each gear cone to confirm "good to use" or "replace".

 

[JodysTransmissions]

I have recently done business with Jody's Transmission. He has quality parts and good advice.

X2 on Jody :thumbsup:

Steve and Rich.......Thank you.

 

[HawkX66]

Look at the gears and cluster gears on my website here Muncie at the bottom of the page and make sure you have a good arrow head shape on the gears where it slides into the slider. Same goes for the slider. I show new and worn gears and sliders here when I rebuilt my M22.

Awesome site Mark. I'm going to go back and look at it in more detail. Thank you.

Degrease it and scrub it with a scotch brite pad. Paint always looks like paint.

I hear you on paint. What do you do to stop it from oxidizing or do you just let it because it probably will never get too bad?

You should use the 20lb detent spring upgrade for your sidecover. Your M21 looks great, but you should get it apart to actually see what is needed.

You will have to measure the synchronizer clearance on each gear cone to confirm "good to use" or "replace".

Thanks a lot Jody. I'll definitely think harder about pulling it apart, but it shifted well before it was pulled so I'm leaning towards just leaving it alone for the time being. I can always pull it later if I need to. The spring is an easy one. I'll do that. Thanks for the suggestion.

 

[JodysTransmissions]

Awesome site Mark. I'm going to go back and look at it in more detail. Thank you.


I hear you on paint. What do you do to stop it from oxidizing or do you just let it because it probably will never get too bad?


Thanks a lot Jody. I'll definitely think harder about pulling it apart, but it shifted well before it was pulled so I'm leaning towards just leaving it alone for the time being. I can always pull it later if I need to. The spring is an easy one. I'll do that. Thanks for the suggestion.

You can measure the synchronizer clearance with the sidecover removed by using a feeler gauge.

 

[HawkX66]

You can measure the synchronizer clearance with the sidecover removed by using a feeler gauge.

Great. I'll do that. I think I might at least remove the main shaft so I can replace the gasket on the rear plate between the case and the tail shaft. I just don't want to press any of the gears off etc. Once I get that out, I'll take a closer look at everything.

 

[HawkX66]

You can measure the synchronizer clearance with the sidecover removed by using a feeler gauge.

Do you have a site to order from? I'd like to grab a gasket/seal kit and that 20lb spring from you.

 

[steven c]

Thanks for the link, always looking for additional Muncie info. I need to actually sit down and learn these. They kinda multiply over the years, have five out in the garage. Two I know have bad 1st gear (missing teeth)