Qblue92

I've been fiddling with my mid-60's Muncie, getting it ready to install in a few weeks. While I was adjusting the shift linkage, I noticed that it will just barely stay in 4th before it pops out. None of the other gears do this. I took the lever off, and turned it with a crescent wrench. It does the same thing. It won't stay engaged in 4th.
What do you think is going on inside??

00fxd

kinda shifter?

knight37128

Take the cover off and take pic.

Chuck Gongloff

Turn the yoke on the back and see if it'll pop in.

If not, I'd look at synchro rings, maybe the fork itself, maybe something more critical within the trans. Chuck

northern

If it pops out of gear while you are driving it, it might be the 3-4 slider and/or synchros that are worn. But if this is happening while it is not running, it sounds as if it is not fully engaging the gear.

As someone suggested, you might have to pull the side cover. Maybe it is something simple to do with the fork.

plaidside

If it is popping out of gear while driving the syncros will not help.
You have a worn slider and gear.

Qblue92

The trans is sitting on my work bench. I've never driven with it. It was pulled from a '62 that hasn't been driven since '71. It looked really clean inside. Nothing looked bad, but I'm no expert.
Its a stock shifter with the muncie linkage.
I'm taking it to a friend of a friend tomorrow to investigate. Thanx for your input....

knight37128

Sorry I could not help. Manual trans are hard to tell without seeing inside.

Hope it's nothing.

Patrick67

I had a Muncie M-22, which popped out of 4th gear and into neutral when I let off the gas at 30 mph. It was the slider sleeve, FWIW. PT

GTR1999

I agree with the above on the sliders and gear. Look at the teeth where the sliders engage. The slider is the hub that "slides" over the brass syncro and engage the little teeth on the gear. 4th is the input shaft and smallest gear. It is not part of the main shaft but rather rides on a bearign cage the main shaft fits into- maybe there is play there? I'd look at the teeth first though. They shoud be a sharp pointed pentagon shape, broken, rounded, or chipped teeth are a bad sign.
The forks are brass and could be worn or bent. If you see wear marks on the full 1/2 moon then they are worn.
Put it in 2nd gear to remove the cover.

StrayDog

Worn syncros, usually the 2/3 goes first...........The Dog

chewy

Something is out of wack. All of the previous ideas don't explain why it really doesn't go all the way into 4th gear. If it pops out of gear when you let off look for sliders,dogs (their springs) engagement teeth and a really bad or loose front bearing. You don't have that problem yet, it's not going all the way into 4th. If you could get some pictures of the side cover inside and the input, mainshaft area it might help.

Qblue92

I got a preliminary report. It has a broken gear or something that assists the synchro to work. It would only 1/2 way engage in 4th and pop out. Shouldn't be too bad to fix.