Technical Three speed Saginaw stuck in second gear

No, you can't do it on a motorcycle.

I put 85 k miles on a Muncie 319, the overdrive version of the 318. All the advice has been great. When I changed out my Muncie for a Saginaw, they were the same length, therefor no change to the driveshaft.

My advice:

On a budget or not putting a whole lot of miles on the car? Fix and enjoy the Muncie.

More miles and money for a 3 or 4 speed Saginaw? Buy the Saginaw. BTW, your shifter will probably work on the Saginaw.

 

Will I still need to change the yoke on my driveshaft with this trans?

 

My '65 Belair came with the same Muncie 318, I swapped in a borrowed M21 Muncie and don't recall changing much else, the length was the same so was the input and output shafts. I had to give the M21 back after a while and put in a Saginaw 3-speed out of a truck, came with the shifter. If you can find a truck Saginaw you get the synchro 1st gear and your shifter might even work.

 

Why do you say this, will it not work properly with his current transmission? I ask because I do not know and I am the person that sold him the shifter here on the H.A.M.B. Feeling kind of guilty for selling it to him if it will not work.

 

If I remember right the short tail shaft 318's were used with two piece drive shafts and the long ones with one piece drive shafts. The long tail shafts were the same length as the later 3/4 speeds.

 

I think it will definitely work on BOTH. I had to make myself a bracket to hold the shifter and then created a bent and welded 'over and up' to move the shifter away from my leg and towards the middle of the floor.

That was a very fine gesture to sell him that shifter, very rare and a real problem solver, you are a good man WARHORSERACING!!!

 

Chevy cars starting in 1966 had the full syncro 3spd Saginaw trannies. All of them as far as I know. You do not have to find a truck version.

 

Apologies to the OP. But, I do think this can give people the idea that it can be done, and can be done successfully to move the shifter forward from the bench seat and away from my 'go leg'. I have 118 K on this set up. The first set up was with a Muncie 319, the version you see here is a 1969 Saginaw 3sp+od that I've had on for eight years and approx 40k miles. The shifting is crisp and tight, as you can see from the shift dogs on the shifter cover I used the smallest radius which made the 'H' pattern close and easy.

 

Most of the Muncie 318 transmission had the course (17 spline) slip yokes; the later versions of the Muncie 318 had the fine spline (27 spline) slip yokes. Yours is a course spline and to use almost any other transmission would require a fine spline slip yoke. The early Borg Warner GM 4 speeds had a course spline slip yoke, the early Powerglides (till 66) had the course spline slip yokes, the Muncie M-20 and M-21 4 speeds had the fine spline slip yoke as did the TH350, 700R4, 200 4R, Saginaws (3 and 4 speeds), and a "few" other transmissions you probably would't consider using. The later Super T-10 4 speeds, M-22 Muncie 4 speed, TH400, all used a large slip yoke with 32 splines. Correct me if I'm wrong guys!
I am Butch/56sedandelivery.

 

Slim I have a yoke that fits trans I will throw in with trans.

Pat

 

Did work now with the linkage in the other holes?
I agree with post on the last page it sounds like the stroke is too long and needs to be adjusted.

 

Thanks. I'll use both. I'm working on getting to NY sometime next week. I'll message you to see when you are free.

 

Shortened the length on the 2-3 rod. Taking for a test drive today. Works back and forth in my driveway.

 

Took it around the block in larger concentric circles. 1 mile, then 2, then 3. Transmission is sure noisy. Maybe because there is no sound deadening mat under the loop carpet. Didn't pop out of gear though. Tomorrow? 5 mile round trip.

 

Was it you that posted a few month's back about missing shifter linkage for three on the tree with this car?

 

That was me looking for linkage.

 

Personally ,you'd be better off with a full syncro saginaw.

But if you just want to patch it and drive it, find another Muncie sm318 [even a long version]
Just swap tail housings. The output shaft comes out with the tail housing so it is easy.

A bearing kit is about $70 which is more than the value of the transmission

 

So do the needle bearings if one hasn't ever opened one. Now it's hunt for all of them followed by how many is there suppose to be followed by one sunk in remaining gear lube in case that was over looked. Oop's.

 

Maybe it is me, but I find manual transmissions easy peasy. Things like needle rollers are part of what we check for everytime.
The day before Covid 19 lockdown, We grabbed a few T5's from friends that needed rebuilding [it helped pass the time away, tinkering in the garage]

 

Took the car for a 30 mile round trip today. About 3 miles from my home I went to shift from 3rd to 2nd to go over a steep hill and the thing started chattering again and got stuck in 2nd. I limped home and put it back on the ramps in the garage. Time to pull the cover off again.

 

The synchros in the slider drum are probably worn; these drums used to come with the synchros staked into them. Now, you're lucky to even find a drum, and there are two for different ratios and they can'/t be mixed up. You can buy the synchros separately, but you have to have a way to stake them in place. That's my best guess. I'd find another trans, better to find a full syncro 3 speed or even a 4 speed. Maybe the S-10 5 speed would work for you since your car's a six. BUT, then you have to deal with the electronic speedometer issue (there are modified extension housings to go with a manual speedometer. Are you using the correct gear lube for brass synchro rings? Some are no longer compatible with brass rings. I am Butch/56sedandelivery.

 

Had the side cover off and on another 2 times today as it kept getting stuck in 2nd. Took it for a ride again and now am using first and third till I can get another trans.

 

I picked up a trans from Frank32 who had one sitting in his garage. 51,000 miles on it. Crisp shifting trans from a mid -60's Suburban. The tail shaft housing is not drilled for crossmember bolts so I will change out the housing from my trans this weekend.

 

Today I had a chance to pull the Muncie 318 from my car. I had a spare trans from a 1958 that was still pristine so I used that and not the trans from Frank32. I'm still saving that one. I had my son bench press the trans from the ground while I helped wrestle it into position from above via the access panel that I have in the trans hump. After all of that, I fed the driveshaft through the tunnel only to find out the driveshaft yoke is fine spline. Apparently in the past, it was changed out as well as the trans. My bad. I must remember the adage "never assume that you have a coarse splined yoke in a 1964 Chevy".

 

Or if someone has a coarse splined yoke. I think I'd like to have one of those also.

 

You already have 2 transmissions, Why don't you just swap the mainshaft and tail housing.

The trick is to stand the trans on it's nose [between 2 blocks of wood] and lift the tail housing up, so the needles don't fall out.
Then get some circlip pliers and swap the 1st gear over [so it stays with the respective transmission]

You need to pack the needle rollers with some grease in the back of the input , and carefully lower the mainshaft back in.
All your speedo drive ,driveshaft yoke/ length etc would remain correct etc

There would be more work involved in pressing a new yoke onto the driveshaft.

The majority of the work is the actual install back into the car.


Edit : here is a youtube video on how to disassemble these "no brainer" transmissions [only the first 2 minutes are applicable]

 

I pulled apart the broken trans today and discovered a completely demolished main shaft bearing. the main shaft was rattling around in the housing.

 

Inside look at the tail shaft housing. The main shaft still has the inner bearing retainer on it. Can I tap this off somehow or do I go to a transmission shop to pull it off and press on a new bearing?

 

Looks like you may have found the problem.