TC35 Shuttle Shift, Won't Engage When Hot

[Wild Bill the 2nd]

Got a chance to run the tractor tonight after work. After 45 minutes of driving and shifting my issue was back.

I-Parked the tractor, turned it off, tried to shift, made no difference. Still would not shift.

II-Took the seat and cover off of the tractor and the transmission was at 110 degrees. Not too hot.

III-Took a video of the view into the transmission

IV-Clutch pedal free play did not measure any different from when it was cold. I have not adjusted it back to the prior setting. After looking inside the beast and watching it try to shift I think it has to be something in there.



The collar that the fork slides (assembly 13) just does not want to move. Sometimes the syncros look like they are out of alignment preventing movement and sometimes they look like they are perfectly lined up and still nothing wants to move.

It's all getting too real... I still had a bit of hope before tonight.

 

[Wild Bill the 2nd]

Had a mechanic (who's outfit used to sell New Holland tractors) stop by the house yesterday. We got the tractor up to temp to where I started having some shifting issues and we looked around inside the trany. Unfortunately I am no closer to a definite solution. We all but ruled out the linkage binding.

If you ask me it is looking like it might be a bearing issue. Perhaps making the shaft hard to turn at a certain point in the rotation. When it is in this hard spot the shaft will not rotate freely in order to allow alignment for the shift. Or maybe it is in that collar that slides in order to engage fwd/rev.

What ever it is it will not be known for sure unless the tractor is split. My biggest fear is, that since the problem does not show up until things are hot, the cause could be overlooked when tearing it down when cold...

 

[Harry in Ky]

With two synchronizers on the same shaft, why would a bad bearing affect only one of them? These are ball bearings, so a problem there would most likely create a noise, vibration or both before it would affect the shifting. You will see your problem once you get the synchronizer out on the table.

 

[RickB]

With two synchronizers on the same shaft, why would a bad bearing affect only one of them? These are ball bearings, so a problem there would most likely create a noise, vibration or both before it would affect the shifting. You will see your problem once you get the synchronizer out on the table.

Not quite a month later, same advise. Synchronizer isn't shifting. The shaft has no radial or axial movement, hint: it isn't a bearing problem. It's the synchro.

 

[Wild Bill the 2nd]

This transmission stuff is all new to me and I was / still am in denial. I was thinking that an issue with the synchro would be visible from the top side. Like ground teeth or lack of movement.

We will find out what is going on fairly soon. Started the disassembly last night.

 

[Wild Bill the 2nd]

Thank you by the way for all of your input, I may be a little dense but it just wasn't / isn't making sense to me. I'm sure it will once things are opened up and I see how the internals work.

 

[RickB]

This transmission stuff is all new to me and I was / still am in denial. I was thinking that an issue with the synchro would be visible from the top side. Like ground teeth or lack of movement.

We will find out what is going on fairly soon. Started the disassembly last night.

When it won't shift? That's a lack of movement.

 

[Wild Bill the 2nd]

What I meant is that the syncro freely rotates when you touch it with a screwdriver. It does not appear to be bound up at all.

Funny thing, this afternoon my New Holland mechanic called and he had a response to his New Holland "Assist" inquiry about this issue. Supposedly these exact symptoms have been seen at least one time before. They said it was a tractor with only 80 some hours and it turned out to be the pilot bearing in the flywheel. Not exactly sure how that would ever manifest itself with those symptoms but I will certainly check it out on my way to the trany.

 

[Harry in Ky]

Your problem is NOT the pilot bearing.

 

[Wild Bill the 2nd]

Split the tractor and torn down the transmission tonight with the New Holland mechanic. There is nothing that jumped out at us as excessively worn. The 3 keys that run in between the inner and outer splined gears look slightly worn but not too bad. Not sure if that would do it. The syncros looked good. They were well outside the wear tolerance.

Here are some pics, though I don't know if they can show enough to be of any help. If anyone wants pics of any specific parts or combinations of parts just let me know. FYI, as expected, the pilot bearing looks just fine.