Trany Problems

P

Pete F.

Junior Member
So my transmission has been fine all summer. Yesterday I started the car went to take it out of third and the shifter was locked in third.
Today I took the top off to find that the synchro hub had travelled to far and the balls came out.
Anybody have any ideas , the hub seems to have about 3/16 for and aft play
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My guess is the bolt holding the universal joint on the output shaft is loose allowing excessive end play in the output shaft and the synchro hub moved too far rearward when you last shifted into second gear. You will have to remove the synchro parts to reassemble it. I have never tried to do that with the trans in the car. I think you will have to remove trans to repair it.
 
Zeke3 said:
My guess is the bolt holding the universal joint on the output shaft is loose allowing excessive end play in the output shaft and the synchro hub moved too far rearward when you last shifted into second gear. You will have to remove the synchro parts to reassemble it. I have never tried to do that with the trans in the car. I think you will have to remove trans to repair it.
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Wow that’s not what I wanted to do at the end of the season but it looks like I’m going to do that thanks


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That syncro hub is supposed to move back and forth on the main shaft smoothly. If it did not and it stuck toward the 2nd gear then when shifted into 3rd the sleeve could uncover the syncro balls allowing them to fall out. From your photo it shows the hub is too far rearward (toward 2nd gear). The hub you have has the brass syncro rings built in to the hub. They are not visible unless the transmission is disassembled.
The hub is the central part of the syncro on the main shaft 7105, the syncro sleeve is the outer part that covers the balls 7106.
 
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Could be a bunch of stuff, but something is out of spec allowing the hub to slide too far forward.

Give Mac VanPelt a call. He strongly recommended going to the "block" style of detents on the hub instead of the balls. They prevent this from happening.

While your in there, replace your brass synchros rings. The one you can see in the picture is shot.

If you don't already have it, I recommend purchasing his transmission book.
 
I'm rebuilding same style transmission.

That early Syncro whill have to come out, get new ball and spring kit, piston ring compressor and a BFH to get it back together.

But since you have to take the trans out and take it down that far might as well as refresh everything while your in there.
 
There is a sleve KR Wilson #BV39 which is to slide the balls down when assembling I belive.. I just went to shop and looked at the one I have. Had it so long for.got and have not done a trwanny for many years -- teen age years !! At 83 memory is not my strong point at this stage of life.
 
Is it possible that the selector fork has travelled to far for top gear ,there are stops built into the gear box top and the spring loaded balls 7233 that lock into the 7241 on Petes illustration
 
FlatheadTed said:
Is it possible that the selector fork has travelled to far for top gear ,there are stops built into the gear box top and the spring loaded balls 7233 that lock into the 7241 on Petes illustration
Click to expand...

That was my first thought, they look like the detent balls to the shift levers.
 
Some times thats the problem ,I have a trans in my shop that has some flat washers over the selector shaft to limit the selector fork travel,
A band ade fix
Lawrie
 
My guess is the synchro wore out . . . allowing the collar to travel too far. I had that happen on a 39 Box (with the late style synchros). The car was stuck in 3rd gear.
 
Anyone have the link to the posting a couple of months ago?? Fellow had the same problem lots of photos and link to his posting on the HAMB. I have searched without luck.
 
Well, you going to have to pull the transmission and while it's out think of it as an "opportunity" to R&R everything along the way. How's the U-joint? Better to change it out now rather than later. Our "hobby" is always a can of worms that eats dollar bills.
Enjoy the adventure... Chap
 
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