2155 4x4 JD Transmission Problem

[Bog Hopper]

Lost gears except 3rd and reverse. Cannot put shift into other gears. The clutch seems OK. Use the clutch to put tractor in 3rd or reverse. No noise. Just lost all gears but 3rd and reverse. Just hoping for some advice or guidance on what may be the problem. I know it is a collar shift transmission, but have not been into it yet. Thanks!

 

[Spanner]

Might be a failed pin on the shifter arms? Sounds like you're going to have to open it up.

 

[Phillip w]

My allis Chalmers pulled a similar trick. It was a shift fork. Did not cost me a dime. Just pulled the top off the transmission get everything lined up and put the top back on the transmission. It was kind of a pain in the rear, it took 3 tried at it to get right, lined up, and shifting correctly. I have heard allis Chalmers has weak transmission but can't confirm or deny that. When mine done it, it gave me no warning and got stuck in reverse.

 

[beenthere]

Had an 8N Ford that was notorious for that... getting stuck in forward and reverse. Usually happened when working in the woods on a side hill and pulling out logs.
Best preventative was to let the clutch out between shifts. If stuck in forward gear, will find that out when clutching. Can then work the tranny out of that gear before selecting a different gear.
Worn parts led to the problem.

 

[Bog Hopper]

Thanks guys... Hoping when I open it up, it is something simple.

 

[Bog Hopper]

Spanner, you think it might be possible to get to that pin from taking the top off the case or do you think I will have to split it open to access the pin? Never been inside or had to work on this one..

 

[Phillip w]

Spanner, you think it might be possible to get to that pin from taking the top off the case or do you think I will have to split it open to access the pin? Never been inside or had to work on this one..

If it is the pin I am thinking he is referring to, it is basically on the "end" of the gear shift and there is a fork type deal. If that is the problem, it is a cheap fix and not to hard to get to.
You should have about 6-10 bolts to pull the top off the transmission. Were I ran into trouble is when you put the top back on the transmission, Everything has to be just so in order for it to shift and work right. On my allis Chalmers there is a fork type deal that work the reverse. That was a big big big pain in the rear end. Seeing the problem is easy. It is getting everything in order and the top back on that is tough. Took me 3 tries.

 

[Spanner]

Yes, take the top cover off. You should at least be able to see where the problem is and manually shift the gears with a pry-bar to isolate the defect.
Take pics as you go.

 

[Spanner]

I'm thinking one of these forks is not connected to its shaft. Possibly dropped out of the collar and binding.

 

[Zebrafive]

The shift forks are held to the shift rods with set screws IIRCC the set screws are safety wired.
You need to remove the rockshaft housing to check.

I am thinking the stamped part riveted to the forward end of the shift rod broke.
You need to remove shift lever housing to check.
If a shift rod needs to be replaced you will have to split the tractor.
Broken part may be able to be welded back on to save splitting the tractor.

 

[Tx Jim]

I agree with Zebrafive on broken shift rail tab that gearshift handle is suppose to sit in. I've seen several broken tabs re-welded to shift rail. I also suggest to remove shift cover for a visual inspection.

 

[Bog Hopper]

THANKS everybody for your input. You guys are great and have given me some really good advice. I live in GA. Tractor is now in NC in a tomato field. Will bring it back sometime in the next few weeks. I will take plenty of pictures and once I get into it and take the trans cover off, I am sure I will have a lot of questions. Thanks for your time, patience and experience.