Muncie transmission?

I have found a munice transmission (3925660) with a t/c adpater from advance (jeep #1001) that is bolted up to a 225 with no t/c. The back of the adpater to the t/c case looks like for a lack of words the state of texas. Now I have learned ALOT of info from this site and when it comes to transmissions and the 225 it sounds like everybody it going with the sm465 or sm420. and I have a few Questions?
Is this a good transminssion for the jeeps?
Have a warn overdrive will this bolt up too it? ( dont know what my spine count is on the overdrive)
Im looking to redo the drivetrain this winter and trying to get everything in order so my down time is not long. Arizona is the best time for a jeep in the winter
Thanks again for all the help and any feed back will be taken.

 

Re: munice transmission?

There are a ton of factors to consider.
What do you use your Jeep for? If you use it off road you might want to consider the transmissions you mention with a low first gear. I am not familiar with the Muncie you list but check gear ratios. No use going to the trouble of swapping transmissions and not being happy with it.

 

Re: munice transmission?

I dont do any rock crawling, mostly out in the woods on some hunting trails or desert running around. looking to put something in that is better than the 3speed i have now from the factory. and if the motor is out i want to address it than not later. thanks for the heads up on gear ratios. will do some digging around for that info.
what would be a good ratio for my 4.88?
Thanks again

 

Re: munice transmission?

The advance adapter 1001 is for the muncie 4 speed from the 60's in most gm products. There is the M-20, M-21. and the M-22. These don't usually work the best for trail rigs.

Mike

 

Re: munice transmission?

I think it is the t86 but it has been a while since i looked and i cant remember off the top of my head...This transmission just fell into my lap after saving another 225 jeep from going to the scrap yard and im trying to decide to keep it or sell it and pay for the drivetrain rebuilt on my 70. If i ask the boss (wife) everything is for sell until we are in the backwoods with the family having fun, but that is everybody story im sure.
Thanks again

 

Re: munice transmission?

IIRC the Muncie has a higher (lower numerically) 1st gear than a stock 3 speed. They are fun to drive on the street but of no benefit for trail use. You are gaining an extra gear and a lot stronger trans.
The Warn overdrive bolts to the t/case, not the trans, so as long as the spline count and gear teeth match it will work.

 

Re: munice transmission?

when I bought my jeep it had a M21 behind the dauntless with 4:88s ,,,,super smooth to shift and great for dunes and street but not at all for low speed rock trails .mine died ,,,,the pocket bearing froze to the main shaft and I drove it all the way back from the dez in 4th . I knew at that time I was going to rock crawl this jeep so I used parts of it in my Olds drag car and I ditched it for a ford T-18 .

 

I love the SM465 with 4.27 gears. This is the best transmission I have ever had. Glad I installed it.

 

Re: munice transmission?

As noted, that kit is the mainshaft (6 spline) and tail housing to mate Muncie M20, M21, M22 to a D18. I can't think of any reason it would not also work with a D20.

M20 = 2.54:1 ist gear for most, 2.56:1 for early versions
M21 = 2.20:1
M22 also 2.20:1

They are relatively stout and light and I don't think an M22 would really have any problem with 500 hp.

Certainly not the best gears for rocks and I probably wouldn't try running one behind a 225. The 2.56:1 M22 (aftermarket) I am using behind the 381 sbc in my 3B works ok, but only because there is a lot of torque below 1000 rpm and it takes a tough spot to kill it at 500 rpm.

I would be selling it and getting an adapter for a SM465 if you want to run the 225.

 

Re: munice transmission?

Back in the day, the Borg-Warner T-10 was a popular swap for some Jeepers. The Muncie would have similar ratios. However, it was my understanding that these Jeepers spent most of their wheeling time at the dunes, not in the rocks.