Ask The Mechanic

By Steve Thompson
Progressive Farmer Contributing Editor

Ron (reader): I have heard that clutches are “funny birds,” but the one in my tractor is not that funny. As a matter of fact, it’s turning me into an “angry bird.”

The problem that I am having is with the clutch on my John Deere 2555 tractor. The tractor has around 4900 hours, and the clutch will not always release when I push down the pedal. Sometimes it releases just as it should, but other times it will not release at all.

To stop the tractor, I have to shut off the engine or kill the engine by locking the brakes. Then, it won’t go into gear after it starts until I push down and let up the clutch pedal numerous times with the engine running.

I never know if the tractor is going to stop when I depress the clutch, and this is dangerous. I almost ran over a cow the other day. Could it be there is rust on the transmission shaft spline where the clutch plate runs, allowing the clutch to stick?

Steve: A clutch can do funny things, as you have experienced. Something is causing the clutch to release in an unpredictable manner, and you are doing the right thing by trying to get to the problem before it causes an accident. Many times, oil getting on the clutch plate will make it stick. After you get the clutch unstuck, will the tractor clutch operate normally for the remainder of the time you use it that day? We can go from there.

Ron: No. The clutch has a mind of its own. It will run OK for awhile, but I never know when it is going to stick again. After I finally get it released by killing the tractor with the brakes or killing the engine, then I can play with the pedal for awhile, and it will eventually let me shift gears again.

Steve: OK, let’s take it to the next step. Since your clutch can stick the same working day after you get it released, that pretty well eliminates oil on the clutch and trying to clean or burnish the clutch plate (making the clutch slip by putting the tractor in a high gear and lightly letting out on the clutch for a few seconds to remove any oil on the clutch plate).

If the fingers were worn off the pressure plate or the throw-out bearing was going out, the clutch would act in a predictable manner. If the pilot bearing in the flywheel was trying to seize, you more than likely could not free it up by playing with the clutch pedal. I don’t believe you have a problem with rust on the input shaft where the clutch plate runs.

Try one more thing before you split the tractor. When you have the clutch working properly, stop the tractor and tie down the clutch pedal. Leave it that way until you use the tractor the next time. Drive the tractor and see if the clutch sticks again. We’ll go from there.

Ron: I tied down the clutch pedal and drove the tractor the next day. Everything went OK for about 30 minutes, and then, for no reason, the clutch stuck, and I could not stop. Now what?

Steve: You have chased it down to something being wrong on the inside. Something is getting between the clutch plate and the pressure plate when you depress the clutch, not allowing it to release at different times.

I would split the tractor and see what is loose in there.
I have seen pieces of clutch lining flake off and cause this problem. I bet it won’t be hard to find the problem. Split the tractor, and let me know what you find.

Ron: We split the tractor and found a couple of springs had come out of the pressure plate and had wedged the clutch disc. Of course, they could drop back in their place at any time (probably when I was playing with the clutch pedal), which would allow the clutch to operate properly until they decided to come out again.

Steve: Good job! Now you have a tractor that is safe
to drive. Your cows will like that.

(BS)

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