Clutch is stuck!

[Tim_D]

Anybody got any ideas for how to free a stuck clutch on a B20 Hydrostat? I took the dealers advice and parked it up against a tree, locked in 4WD-Low and popped the clutch a few times. Well the 4WD works! Dug some 6" ruts really quick! I understand the only sure way to cure this problem is to split the tractor in two for a clutch replacement. I don't want to do that until I have exhausted any/all potential trials to break the clutch free. Any suggestions would be appreciated.
Tim

 

[Henro]

Just for clarity...around here, popping the clutch means engaging it rapidly, which could not be done if the clutch was sticking...so I take it you mean you pushed the HST pedal quickly while keeping the clutch pedal depressed with your other foot, right? The goal being to try to break the clutch free. Important to keep the clutch pedal depressed when doing this...

One thought that came to mind would be to use the tractor doing some kind of work for a while with the clutch depressed. You would not want to do this if you are on hills though...except maybe if you were holding the clutch pedal down with you foot. Even then, having the clutch break free on a hill, and the tractor start drifting suddenly downwards, might not be a good thing, to say the least.

For lack of a better idea, I'd probably try running the tractor a while, on level ground, with the clutch depressed to see what happened. Also, some have reported moving slowly towards a tree and impacting the tree at slow speed with the loader bucket as a way to shock a stuck clutch free...

 

[theboman]

Have you crawled under your tractor and looked for a stick, etc. lodged in the linkage?

 

[Junkman]

If this is a wet clutch, then there is no way to break it apart from the pressure plate. If it is a dry clutch, and there is an inspection plate, possibly you can get something in there to pry the two parts apart. When there is a hydro involved, then there is no way that the pushing on the tree method will work. The clutch is either engaged or not, and the tractor movement is controlled by the hydro, not the clutch. I believe that you are doomed to doing the repair the old fashioned way... take it apart and put in a new clutch facing.

 

[Henro]

<font color="blue"> When there is a hydro involved, then there is no way that the pushing on the tree method will work. The clutch is either engaged or not, and the tractor movement is controlled by the hydro, not the clutch. </font>

Let's carry this thought a little further...

On a hydrostatic transmission tractor, the clutch is still somewhere in the power circuit, between the rear wheels and the engine, isn't it?

I know on mine if I push in the clutch, while the engine is running and the HST is in gear, the tractor will drift just like a standard shift would.

So it would seem to me, if the clutch were rusted to the pressure plate, and the clutch pedal were depressed, and the tractor was against something while the HST pedal was pushed causing the tractor to want to move, then the net effect would be the same as it would be if the tractor were a gear transmission tractor.

I'm not trying to debate the possibility that the HST might not produce the amount of torque on the clutch disk that a gear drive might...but it sure seems to me that it would be possible to break a clutch plate free from the flywheel on a HST tractor, using the same methods that have been prooven to work on gear tractors.

What am I missing?

 

[KennyV]

Henro,
as usual /forums/images/graemlins/cool.gif… you have nailed it.

You are not missing anything.

If he dose as you described it should free up. Using high range will put more torque on the clutch, but hi or low will get it done. KennyV.

 

[Pks]

According to my B2400 HST parts book, the clutch feeds power from the engine to the HST pump. The HST pump then acts like a geared transmission in that the power is connected from the clutch to the rear wheels. Therefore the clutch can be partially engaged which would then feed a proportional amount of torque to the wheels.

FWIW, I think Henro's thoughts are right on the mark.

Are you sure the clutch-fork is engaged against the throwout bearing (not sure how to test that)?

The attachment shows the B2400 HST clutch housing and bearing.

 

[Kiohio]

I heard this from a friend of mine on how to fix it without splitting, at least give it a shot. Drive the tractor alot use it etc get it good and hot. Then when finished press the clutch pedal all the way down and lock it. Let it set/cool overnight. It should be free in the morning. If that doesn't work I would try one more time doing everything the same...get it warm etc. Then go to that tree...let it cool overnight and try to move the tree the next morning. It's worth a shot.
Have fun!!

KO

 

[chucko]

does the cluch not also work the PTO? if so with the pedel in an a good load (like a tiller) on the pto might work

 

[Pks]

Chucko, good point!