I posted this question in my build thread, but no one has responded, so I'll try in a separate thread.

I discovered that I have a lock-up problem whenever I take the tranny out of 4th gear before I come to a complete stop. The truck rolls to a complete stop, with or without using the brakes, and at the last second, it will occasionally lock up. Sometimes it's barely noticeable on take off, other times it has to be moved in 1st gear to get going. Once it's moving again, there's no drag or binding noticeable.

If I leave it in 4th until stopped, it works normally. If I put it in neutral, it sometimes locks up. If I leave it in 2nd or 3rd, it sometimes locks up.

So, what's wrong with my transmission?Any ideas are welcome.

 

I would jack up the rear of the truck, both wheels off the ground. Of course, block the front wheels securely. Kick the truck out of gear with the parking brake off and turn the rear wheels. Perhaps you have a binding, U joint or bad bearing in the rear of the tranny or differential. If I remember right, you changed oil in the tranny early on. How about the rear end? If nothing seems to be binding with the above procedure, you can try starting the truck and going into gear with the rear wheels jacked up and the fronts securely blocked.

 

I changed the tranny oil and the rear end oil at the same time. The part that really puzzles me is it drives fine once it's moving. It only locks up sometimes when it comes to a complete stop if I'm not in 4th gear. And with the brake off and in neutral, it'll roll right back out of the garage.

I'll try jacking it up this weekend and see what I find. Thanks Ray.

 

Synchronized transmission? If so, maybe a busted synchro causing interference(?). Does it shift without noise (when it should)? If nothing obvious, might be time for a visual inspection.

 

When you say it locks up, do you mean the lever gets stuck? Or is it in 2 gears at once? I'd pull the top off the trans and make sure the ***** and plungers for the detents are all in good shape. There is a mechanism to prevent going into 2 gears at once that could also be hanging up or stuck. Not a trivial problem, if it goes into 2 gears at once while you're rolling!!

 

JRJ's tranny would be a crash box, no synchronizers.

 

Well, this lock up problem got worse this weekend when I took her out for a short drive.

I think it's trying to go into reverse and another gear at the same time. If I back up, then push in the clutch (on a slight downhill slope) it'll roll forward a few feet, and then come to a screeching halt. Maybe there's something getting between the gears? Obviously, I need to pull it out of the truck.

So I looked in the Shop Manual to get an idea of what the gears look like. I've never worked on a transmission. I have replaced them (years ago) but never repaired one.

And what does the SM say to do? Remove the tranny cover after removing the seat. Unhook everything, unbolt the tranny, slide it back to clear the engine, and ..... LIFT IT OUT THROUGH THE HOLE IN THE FLOOR?? WTH?

Why can't the transmission be lowered out of the truck? Is the crossmember in the way?

 

Yes. Do you have an engine hoist? (Cherry picker) You should be able to reach in from the passenger side with that and lift it out. Be sure to drain the trans first.

It's possible the shifter fork for reverse is broken or not properly into the reverse gear. Pulling off the top of the trans might reveal that without pulling the trans.

 

Thanks Ross. I'll try that first.

I don't have a hoist, but I can rent one if needed.

 

You're right, Joe, cross member supports the rear of the tranny. I just don't know how you would easily get it out from the bottom. Do like Ross suggested. You can also pull the side off the lower curb side of the transmission for inspection. My SWAG is that it is a shifting fork problem. Make certain the detent ***** and springs are and remain in place when you pull the top.

 

Not sure if this will work for you...but, I've pulled the trans out of my 54 by using guide pins, and holding on to the shifter, pull back and up into the cab. (course I was younger then) Another thought would be to make up a plate with a hook on it to bolt to the top of the trans. Similar to the engine pullers you see that bolt on to the intake manifold. And, get 2 helpers. Try Ross's suggestion first.

 

Joe, I was just reading your earlier posts about the problem, and it caught my eye that this "only happens when you come to a stop". That sounds an awful lot like the reverse gear sliding forward and into mesh from the inertia of stopping.

 

OK guys. Thanks for the information.

Since I've never opened up one of these trannys, I don't really know what to expect. The Shop Manual is vague, and I understand it's meant for mechanics to use. I didn't know the top would come off. I don't know what I have to remove to get the top off. I saw the side cover is removable when I drained and refilled the tranny fluid.

So, should I drain it and remove the top or the side cover first? Do I have to remove the shifter to remove the top cover?

If the reverse gear is sliding forward, what could cause that, and what would I be looking for to fix it? Would there be a broken keeper of some kind? Is the reverse gear ever supposed to move forward?

When I remove the top, is anything going to fall out... like a spring or ball bearing? And by "removing the top", is that the gear shift mechanism?

Boy, do I feel dumb...

 

Just wanted to close out this thread with what I found in my transmission in case anyone doing a search found this thread.

Go to my build thread and start reading at post #920 for the results.

https://www.ford-trucks.com/forums/1...roject-46.html