Info for rebuilding a 1969 Muncie M21

[jk1969z28]

In the looong wait for my car to be released from body shop prison I've decided to see if I could rebuild my Muncie myself.  Does anyone have any good links showing detailed step by step instructions for both tear down and reassembly.  The tear down is not that tough I pretty much have it all apart except how do you get 2nd and 3rd gear off the main shaft? Press? Beat it with a pole?  :-)  I've seen some poor exploded diagrams and a few sites with some info but missing some details.  Internally everything looks to be in great shape with very little wear if any.  However reverse looks to be a little worn but how can you tell, are they suppose to be a little rounded since they have to be engaged unlike the other gears?  Synchros look sharp.  Any advice for "reskinning the case", I could take it to Jerry M. who does top notch work, but I like doing it myself after all it is a hobby and I'm sure I can do it as long as I have the RIGHT information.  Who has the best parts if I need them?  One other thing, does anyone know what the little disk is in the bottom of the case under the countershaft, it is not in the exploded diagram and does that get replaced?

Thanks in advance,
Jerry K.

[1968RSZ28]

In the looong wait for my car to be released from body shop prison I've decided to see if I could rebuild my Muncie myself.  Does anyone have any good links showing detailed step by step instructions for both tear down and reassembly.

Jerry -

All this information can be found in the 1969 Chevrolet Chassis Overhaul Manual (Section 7).

Paul

[jk1969z28]

Thanks Paul,

I've got that manual, so I thought, it has all the models correct?  And section 7 deals with transmissions but it does not have much info, so I must have the wrong book.  I'll have to get the right one.

I appreciate the info.
Jerry K.

[1968RSZ28]

All this information can be found in the 1969 Chevrolet Chassis Overhaul Manual (Section 7).

Jerry -

Make sure you have the manual I mentioned above.  There is also a 1969 Chevrolet Chassis Service Manual.  The Overhaul Manual is the one you'll need.  It has the Muncie disassembly and assembly procedures along with lots of "how to" illustrations.

Paul

[Stingr69]

http://www.5speeds.com/

There is a good link above for parts and info. I own the book and it is pretty good. Paul also sells a video that is supposed to be a great reference.

The gear stack can be pressed off. Some people will drop the mainshaft on a piece of plywood using inertia to dislodge the gears but that seems a bit too crude for my taste.

I have never reskined a tranny case but Jerry has done a set of valve covers for me. Reskinning looks great but you can't do it yourself. For a tranny I would probably just use simple green and a scrub brush.

You might have a magnet in the bottom of your case. It would be there to catch steel chips from gear teeth etc.

Hope this helps,

-Mark.

[jk1969z28]

Checked and the Service manual is what I have so I will get a copy of the Overhaul manual, thanks so much Paul I had no idea there was another book, thought I had them all.  Mark appreciate the link and the information and I cleaned the disk off and it is a magnet, I would have never guessed there was magnet in the case.  That is why I like doing a lot of this myself because of the things I learn.  Before I took this thing apart I always thought that when you "grind the gears" you literally grinded the gears, then I'm looking at it and realize the gears never disengage from each other except reverse, they just freewheel when not in "gear". 

Jerry

[68Zproject]

Also. go to a Library and look at an old Chilton manual if they have them.  I have one for American cars 1966-1973 and there is a whole section in there of lots of trannys.  I did many of mine back in High School with just this manual.  I can give first hand knowledge that the Saginaw couldn't handle much abuse.

[hotrod68]

I don't think they tell you this in the manuals, but before you go to put the needle bearings in, chill a tub of blue grease in the freezer for a couple of hours. The cold, thick grease will hold the rollers in place slick as a whistle until you can slide everything into place. Good luck!