The Stovebolt Site Forums The Shop Area Driveline 1950 Muncie 3 speed whines in 2nd, also need to double clutch to shift

I have a 1950 Chevy 3100 with a Muncie 3 speed. It whines in 2nd gear and I need to double clutch to go from 2nd to 3rd. I also cannot down shift easily from 3rd to 2nd. I assume I need to rebuild and I am looking for advice. I feel the clutch is adjusted properly. In the 70's when I learned to drive in this truck I don't remember this as a issue. Yes a lot of water under the bridge since that time. Is this a gear issue, synchro issue, bearing issue, or all of the above? I also have a spare that I think I swapped out years ago because it would not stay in 3rd gear, but so much time has passed I'm not really sure where that transmission is now. But it could be a good starting place for learning to rebuild my other transmission, are maybe a source for donor parts. I look forward to your advice.

You're going to have to pull the transmission to see what's wrong. Probobly needs new synchronizers but you'll soon see what all needs to be replaced when you open it up.

Good opportunity to check/replace clutch and throwout bearing, etc.

Clutch and throwout bearing were replaced when the engine were rebuilt. Can I get new synchronizer gears? If so do you have a suggestion as to where to find these?

Anaheim Gear in Anaheim, CA
800-477-1103

Fred

Novak in SLC carrys all sorts of parts for 420 trans.’

Ed

I have a question about pulling the transmission. I am having trouble getting the universal ball to slide back on the propeller shaft. How far is that supposed to slide back? It might be because I have paint on the propeller shaft. Do I need to remove that paint? I can slide the collar nut all the way back to where the propeller shaft start to flair out. I am assuming if I can slide the universal ball back further, that will give me the clearance to easily slide out the transmission. Based on what the manual says all I should need to do is remove the transmission cover and raise the propeller shaft as high as it will go with a jack to provide the clearance. Thank you.

It helps to sand the paint off the torque tube, and use a vise grip chain wrench or a strap wrench to turn the ball back and forth as you pull back on it. Once the ball is retracted, unbolt the U joint and jack the torque up against the cab. Be absolutely sure NOT to have the weight of the vehicle resting on the springs, as there will be a lot of down force on the torque tube. (Maybe that's why the ball won't slide?) Use jack stands on the frame to support the truck, not the axle housing tubes.
Jerry

So that I have this clear, jack the truck up in the rear high enough to get some jack stands on the frame and let the wheels hang down freely. If I am picturing this correctly the axel will hang down and this will also take the propeller tube with it, moving the universal ball back away from the engine.

Fred and Ed... he is describing a 3sp Muncie 318, not a 420 4sp. It has a synchronizer drum which is no longer available anywhere but used or NOS (if you are lucky enough to find one.) Some of the usual vendors stock replacement brass synchronizer rings so that issue is repairable, as long as the inner gears are not worn out.
When I visited the Novak site I did not find anything for a torque tube 318. Don't know about Anaheim.

Clear as mud- - - -The reason for suspending the axle is to prevent getting injured by the torque tube as it slams down onto your body, if you manage to get the ball pulled back and the U joint unbolted. You will still have to slide the ball back to expose the universal joint. Sand the tube shiny, and grab the ball with something stronger than your hands- - - -big channel locks, chain wrench- - - -strap wrench, etc. There are simply no shortcuts for doing things the right way the first time.

Remove the rear wheels and you won't have to jack the frame rails as high to suspend the axle housing and unload the springs. Why is common sense such an uncommon thing?
Jerry

Double-clutching is a sign of worn synchronizers. Replacements are available from the usual vendors. Any lube other than 90wt pure mineral oil will, in time, ruin brass synchronizers.
Jumping out of 3rd is usually a worn shifter fork in conjunction with a worn input shaft and bearing.
Get one of these publications on overhauling a torque tube 3sp. Find one online.

I suggested Anaheim Gear because they have SM318 components. I bought some parts from them recently.
I asked abut syncro assemblies and was told that they are currently rebuilding them.
Fred

Good info... thanks!

Thank you for all the advice. I got the rebuilt transmission installed and it drives great. No more double clutch to shift from 2nd to 3rd and I can also downshift for the first time in a long time.

So that's what my transmission is supposed looks like. I guess I should clean the oil and grease off it.

Looks factory fresh, and I also note the modern brake master cylinder. Is it still drum or did you update to disc up front?

Front disc brakes, rear drum brakes.