drspencer

Planning a drive train rebuild on my '71 350/270 w/120K miles.

I'll be doing the removal/installation of the engine & trans.

Is rebuilding a Muncie M20 something that is easy for a DIY'er, or should it be left to someone with experience.

Thanks

Petes73

You can find directions on the internet. Read up and see if you would feel comfortable doing what it says. I haven't rebuilt a Muncie but did some old Vega Transmissions back in the day. If I don't go with a 5 speed I'll at least give it a shot. Most of the parts are reasonable so why not try.

SD71VETTE

I did mine. Fairly easy but make sure to get the video from 5speeds. Very helpful!!

drspencer

Do people typically reuse the original gears when doing a rebuild (new Italian made gears are ~$500)?

Thanks

Indiancreek

Kind of fun to do. Just make sure you get the correct parts kit, and replace the worn gears. Most of the time you'll need some new stuff for reverse.

Garys 68

If you have a press, then about the only tool needed will be the input shaft nut wrench. So if you want to try a rebuild, go ahead.
Inspection of existing parts is the only grey area, but there are lots of examples/pics online.
You typically reuse the gears unless they're damaged. Always replace stbchros, seals, etc and I would recommend upgrading to torque lock sliders.
Take pics when disassembling, post here with questions.

Indiancreek

Oh by the way, if the shaft hole in the front of the case shows signs of a leak, the fix isn't sealer. A steel insert can be installed to permanently repair an enlarged hole there also. I'd suspect that's online also.

learje

did mine awhile back. only needed to borrow a press from my sons work. heres my thread w a couple pix. id recommend the torque lock sliders and the video from 5 speeds. if i had it to do over again id get the iron midplate as well.

https://www.corvetteforum.com/forums...ons-start.html

http://www.5speeds.com/cart/index.ph...&product_id=68

73C34me

i did mine, with parts from autogear out of new york. I bought a press, which i use for other needs occasionaly, so that worked out well too.

Sigforty

It is a job you can easily do yourself. I had the video from 5 speeds.com and got my parts from Jody's Transmissions in Harding, PA. Jody is a good guy to work with and answered any questions I had. He also sells some matched torque lock sliders. I have a post on here with some pictures. I built my M-20 up to a M22w. https://www.corvetteforum.com/forums...uild-pics.html

drspencer

How likely is it that I'll be able to reuse my original gear set?

Do they typically get replaced?

Thanks

73C34me

you will have to inspect them. I replaced 2nd speed & 3rd speed gears.

jnb5101

It's generally not the gears that need replacing, it's the internal clutches(sliders) and syncro rings that wear. They cause the trans to pop out of gear(clutches) and grinding when shifting(syncros).

Garys 68

Why are you rebuilding? Is it popping out of gear, whining, etc. Or is it just worn synchros?
If gear teeth are chipped, damaged, you'll need to replace. Well the reverse can be pretty beat up and still work.
If it's popping out of gear, could be worn engagement teeth or sliders. If engagement teeth, you'll need new gears. You can open the side cover, take pics, post here.

drspencer

Car is presently running and shifts fine.

Planning a drive train rebuild and want to service the trans while it's out.

Thanks

Garys 68

Go ahead and rebuild with a basic kit, seals, synchros, etc. and get the torque lock sliders. Order the front nut wrench at the same time. It's unlikely you'll need anything more.
There are a few hints that make it easier (like count the countershaft bearings before installation). You can find everything you'll need for instructions online.

Solid LT1

If your transmission is operating well you are probably not going to need a replacement gear set. I would change the syncronizers to the previously mentioned " torque lock " style and a careful inspection of your existing parts should be done to look for possible problems. when you remove the transmission, pull the side cover off and see what the condition of the parts are inside. One word of caution, when you go to remove the counter gear shaft....it only removes from the back side closest to the tail housing, it can be forced out the front of you don't know what your doing, we just had a customer bring in his M-22 and this had been done to it by some IDIOT! Also source you parts from Autogear or Paul located here: http://www.5speeds.com/index.html

BEWARE of the Ebay sellers there are kits full of junk parts out there, buy quality parts for your rebuild!

drspencer

Just got off the phone with Paul at 5speeds.com (what a tremendous resource of knowledge), and ordered his book & video.

Beside the wrench for the nut and a 12 ton press, any other tools, tricks/tips I may find helpful?

Thanks

jnb5101

You'll need a tub of assembly grease to hold the needle bearings in place when you reassemble the trans. Also make a wooden stand with a hole on top that will sit on the floor and is tall enough so that the input shaft will slip into the hole. When it comes time to set the case onto the input shaft, I found that the trans was too heavy to manipulate while it was at bench height.

drspencer

Hmm, can't get my mind around what you're describing.

Do you have any pics of this type of stand?

Thanks