Muncie 4 speed

TimAT

Addict, Cruise-In Bird-Run 1 Veteran
Joined
Mar 24, 2008
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Gladstone, Missouri
Since I've got the engine out and the trans out by default, I figured it was time to dry up that annoying little leak between the main case and the mid plate. Gaskets were perfect, I really don't think the trans has ever been apart before now but I have a new gasket/seal kit on the way.
The real question is- Now would be a perfect time to drill and tap the case for a temperature probe. But where should it go? At the bottom where it looks like GM should have put a drain plug?

Comments, ideas?:hi:
 
:shocking::beer: Hey bub...how you been?? Mary Xmas and all that.....

why a temp probe???
 
Yep, that's where I would put it.

10.jpg
 
Welllll ...... Now that you got out it's maybe a good time to add a temp probe but it's also a GREAT time to replace it eith a TKO or a 6Spd OD tranny ..... Lol.... I mean seriously, if you want to take that vette on the highway at 70mph you need overdrive .....
 
Welllll ...... Now that you got out it's maybe a good time to add a temp probe but it's also a GREAT time to replace it eith a TKO or a 6Spd OD tranny ..... Lol.... I mean seriously, if you want to take that vette on the highway at 70mph you need overdrive .....

:clap: Funny in that when moving to Florida in '97, my car had the 336 rear and a muncie.....4000 rpm at 80...up/down I 95......stupid car would see 80 around Wash DC for maybe a minit, if that, either cops or traffic...typical top speed maybe 60....try that here in Florida, and you likely to get run over.....


:clap::devil:
 
I agree the 5 or 6 speed with OD would be good. Maybe in a year or two. Autogear has an OD gearset for the old Muncie. Just not in the budget right now. As good as the inside of the trans looks- even the rings in the synchros are sharp- it can run for a while- either until it breaks or the budget gets a little better.
 
Drill one of the oil plugs for the temp probe, that won't weaken the case. Maybe that's what you meant, I wasn't sure.
 
I think he means he has a Muncie, not a T10. They don't have a drain, but there is an undrilled boss there. Just drill and tap it.
 
All done- drilled and tapped the case at that lower boss just like Kid Vette's picture. The drill cost more than the tap. 1/2 NPT takes a 45/64 drill bit.

Been a really long time since I did a manual trans. Kind of fun using a BFH to drive out the bearings and shafts. 3 pound brass hammer and a couple of aluminum drifts. It's all back together and turns and finds all the gears.

2.20 low gear close ratio M-21
 
All done- drilled and tapped the case at that lower boss just like Kid Vette's picture. The drill cost more than the tap. 1/2 NPT takes a 45/64 drill bit.

Been a really long time since I did a manual trans. Kind of fun using a BFH to drive out the bearings and shafts. 3 pound brass hammer and a couple of aluminum drifts. It's all back together and turns and finds all the gears.

2.20 low gear close ratio M-21

Tim, can you answer a potentially stupid question of mine? I'm considering putting my M-21 back in the car to pull about 25-30 pounds off the car. My current setup (Nash 5spd box) uses the fine spline (26?) input shaft, while my M-21 (as you know) is the older 10 spline input shaft. I'm going to have to spend time and money one way or the other (new clutch disc and R&R time, or a new input shaft and tear apart time). I've had my Nash box apart several times, but never messed with a Muncie. What's your opinion of the PITA quotient for changing the input shaft (assuming I can find new ones)?
Thanks!
 
a Muncie on a road race coarse? not a good idea. consider a T-101 or a T-101A with a Long rail shifter and a triple disc clutch...you won`t be sorry
 
Changing the input is not a real big deal- other than the trans has to come completely apart to swap it. Autogear has all the parts. They also have some upgrade stuff that looks pretty good too. If you decide to go with the Muncie, give me a call, we could easily do it in a day.
 
Why not just swap out the 26 spline disk for a 10 spline? No need to even change pressure plate?
The input shaft isn't hard to change, but will cost more than a new clutch and take quite a bit more time. ie clutch disk, 2-3 hrs vs input shaft, gasket kit, input nut wrench, 6-8 hrs.
Might be worth it if the Muncie needs a rebuild anyway.
 
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