Technical Muncie Tear Down, What’s Junk, What Can Be Reused?

When my employer got a bead blaster many decades ago, I did a few "bead blaster revivals" on these transmissions.

 

You know, I was just starting to think, "That's actually not so bad" and then:



It looks like that transmission was in really good shape before filling up with water. But it might clean up better than it would seem, at least some of the parts.

I had a BW overdrive not quite that bad, I cleaned it up and put it back together and it was fine for the short time I used it. I didn't use bead blasting, just elbow grease and sand paper and wire brushes.

 

Those parts need "baptising" in industrial vinegar for a few days.
Then re coat them with Molybond [dry film lubricant]

 

Everything on the main shaft is pretty well stuck. I managed to tap off one slider, but it’s time to get ready for the work week. My little blasting cabinet is full of black beauty right now, but I’ll pick up some bead, some better lock ring pliers, and maybe some evaporust and see what I can do. If the main shaft bearing surfaces aren’t murdered, maybe I’ll get lucky. The early ford guys don’t seem to mind a little light pitting in their gear teeth. Maybe I can get by with a master kit and elbow grease.

 

Just my 2 cents worth. Muncie made two series of 4 speeds. 63-65 and everything thereafter which is 66 up to the end of production. All 63-65 muncies have a casting number on the passenger side of the case that ends in 325. The early muncie transmissions had major problems when driven hard because, GM, in their infinite lack of wisdom and buck saving used a design that used a 7/8" countershaft. Commonly referred to as a pin. When heavily loaded, the tendency is to try to push the cluster gear down. The 7/8" pin was too weak and the load caused the pin to elongate the pin bore and things got ugly quick. I had a 325 muncie given to me by a friend that found it stored in his late father-in-law's garage. Since I inherented my dad's El Camino and it had a full syncro 3 speed, I was eager to install the Muncie. Another friend looked at it and told me that I would hate it. I had 2 other Muncies before and experienced no problems. He had a 65 El Camino with a 325 Muncie in it and was towing/pushing the old Blair's speed shop Anglia, which another friend was racing. He put 10 rebuilds on it before he threw in the towel, bought a scattershield and a Ford top loader and had the car 17 years, even after the Anglia was sold off. I figured he was talking through his hat and ignored him. Boy, was I wrong ! After 5 rebuilds and finally having it blow up driving easily across railroad tracks, I waved the surrender flag and got rid of it and sold it to a guy that specialized in building Muncies. He echoed the opinion of my friend about 325 case Muncies. I found a 660 and an 010 case trans. I put a small parts kit, main bearings, and syncros in it and drove it just as hard or harder from 1997 until this year without one problem or failure. At 75, I am doing one last major rebuild on the El Camino and will be replacing the 350 and Muncie with a much modified and destroked 400 down to 377 with roller cam and numerous other go fast goodies and a 5 speed to give me overdrive. The looks of damage in your box look like classic 325 problems. Some people have built fixtures to bore the countershaft bore oversize and hardened installed in the case to prevent wear loading destroying the case and gears again. If it's a 325 case, sell it to a restorer that will trailer it to shows and never will drive it far or hard on the street. Various numbers were used from 66 on and all will produce dependable service. It it is a later case and you have lots of cash, then build it and you should be okay. If not, put it in a box and sell it for parts to a concourse restorer. Good used 660, 661, and 010 Muncies can be had for between $1000-1500. Rock crusher M 22 and the new Italian version bring premium prices. Something to think about .

 

It’s a 660 case. If I remember right from when I looked it up a year ago, the numbers said 1969 Pontiac. Someone beat their GTO like it stole from their mom.

 

Apart from the (surface rust)? it looks pretty good to me, overnight soak in evaporust should clean it up nicely. Fingers crossed for ya, most of my shits cobbled together so l understand

 

I hope so. That I wasn’t ready for that level of carnage in the Muncie. I was going to order parts, come back from family spring break, put a trans together, and stuff my motor in the car. Now everything is off the rails!

 

You can put that T10 main shaft and gears in a 5 gallon bucket of diesel fuel for a couple of days and it will be much better .
It should break it loose enough to disassemble,,,,,,just an idea .

Tommy

 

Saginaw is not a terrible trans either, will hold up fairly well so long as you’re not side stepping the clutch or getting wheel hop, ask me how I know this mine got car sick and blew its guts all over a parking lot

 

Two days in a vinegar bath would clean those gears right up.

 

Citric acid too.

 

I would never pay more than $200 to $300 for a used Muncie. I got mine here in the classifieds with shipping I was $725 into it. I had an issue with the side cover, Auto Gear to the rescue for around $190. The counter-shaft pin was recessed 3/16" and oozed gear lube, a harbinger. The guy who fixed it said it was from a '64 Vette with a 4.11 rear. Like I said, the spinning counter-shaft pin wiped out the mid plate and he used a 1" pin. Funny, the 7/8" pin was unscathed.

He and another guy (older than dirt...) who does 4-speeds have TONS of good used parts they have amassed over the decades. You need to find a guy like that, show him what you have and go from there. All told I am under $1400 in mine and it works great. I need to have my spare shifter rebuilt one of these days.

 

I’ll get it soaking in something asap. Hopefully tonight, if work and kids aren’t too rowdy. For some reason, these things are still like gold up here. Unless they’ve been adapted for Jeeps, they’re all $1-2k in my region. It took me 2 years to find one under $500. I guess we’ll start LS/6 speed swapping in 10 years when everyone else goes electric. I’ll start asking around. Someone’s dad, grandpa, or weird neighbor has to have a box of gears under their bench.

 

I also recommend Paul. I just did a T10 for my 62 Galaxie. It was as rough or worse than your Muncie. I replaced every gear but the cluster. I did use a reverse slider from another T10. I am into the transmission for about $1,200. I started with 2 T10's I bought for $175 plus shipping. In hindsight I would do differently.

Someone had ran this transmission with a bad bushing for a long time. I had to get another tailhousing.

 

No we won't!!!Lol

 

“We” Montanans, not “we” HAMB folks. HAMB people will be running post apocalyptic flatheads on moonshine.

I got most of the Super T10 mainshaft apart tonight. Most of it looks good. The big reverse gear has some serious corrosion. One synchro slider assy is still stuck and the other has a suspicious hub. I’m hoping the cluster and the input/main gear/4th will clean up. The bearings actually freed up too, but I’d replace them and the brass anyway. Pictures:



Everything is all still grubby and greasy. I did a basic wire brush and wipe. I’ll either start blasting or soaking tomorrow night.

 

Keep cleaning,,,,,,I think you are In much better shape now with the T10 unit .

Tommy

 

That T10 is the better unit, for sure. It would be interesting to learn what the first gear ratio is.

 

That reminds me I have a Super T10 in the garage I need to go through.

 

After you price out a T56 you may change your mind.
I’m in the Citric Acid camp, cheap to use and does a good job.

 

I have seen lots of used transmission innards on eBay, find a decent seller and see what they have that can help you out.

 

Amazing how people just ram manual transmissions in reverse

 

I saw 3 rings on the input shaft, just can't remember what ratio they correlate to.

 

If it's a Super T10, three rings designates a 2.64:1 low gear.

 

Shoooo-we muskie! That Muncie is hurting. Any swap meets up your way?

 

Evaporust it. the pits just hold more oil.

 

I took the guts outside and gave them a coffee can gas bath and then choose two rusty parts that I can afford to loose to go first. I’m dunking the big pitted reverse gear and the free hub because they’re both as rough as anything. I’ve only got a little container of evaporust and no citric acid yet, but I do have this green stuff. Let the sciencing begin.

It’s bubbling. That must be a good thing…. If it eats the wire, I guess it’s too strong. I’ll check on it in a couple hours.

 

Looks like you're willing to work at this, good going.
I use weed trimmer line to suspend parts when de-rusting them. Holds up to acids, and other bad chemicals.

 

That’s a good idea.