Weird grinding with clutch pedal pushed in, silent when out

[LincTex]

Hey All,

I just picked up a pretty nice TYM/Mahindra 4110 at an auction "with a new clutch"

Well, it runs and drives great as long as you never push the clutch in!
Then I get the weirdest grinding noise, almost like two plastic hair combs rubbing together very fast.
It doesn't necessarily sound "metallic".

Clutch out and driving around, the clutch "grabs" very well - step on the brakes and you can almost lock up the rear wheels while the front wheels keep pulling you along!

When driving along and you push the clutch in - - as the tractor slows (while still in gear) and the input shaft speed subsequently slows down, the grinding sound frequency INCREASES (starts very low while flywheel and input shaft at near same speed) and is at the highest noise when the input shaft RPM is at zero with the engine running and clutch in.

It DOES NOT sound like a bad pilot bearing at all.... that's really the only part (well, besides the clutch disc itself)..... Hmm, maybe i am on to something here - - what would cause a clutch disc to make a noise like that? When input shaft speed is zero and engine running?

I'm pretty sure I will need to split the tractor to fix this, which I feel confident doing

Can anyone send me the manual page copies that show how to set-up the clutch on the bench?

THANKS IN ADVANCE!

 

[RNeumann]

It is the throw out bearing....

 

[LincTex]

It is the throw out bearing....

Nope - It can't be the throwout bearing, or the speed of the sound would match the engine - which it doesn't.

The speed increases only when the DIFFERENCE between the engine and input shaft is great.

I can drive down the road and step on the clutch as many times as I want to,
and the sound will never appear UNLESS there is a difference of speed between engine (flywheel) and the input shaft (disc).

 

[ovrszd]

I agree that it's disc related. Very unusual. Since we know it's been worked on I'd suspect a problem in assembly. Usually you can't put the disc in backwards. But I don't have specific experience with that model.

Post the answer when you find it. I'm very curious.

 

[Jabonee]

It is the throw out bearing....

Agreed, Release bearing. Known issue.

 

[rdinatal]

By the description it could be in the areas of transition between the engine and transmission.

- Throw out bearing (Release bearing)
- Pilot bearing
- Clutch disk and pressure plate

Replace the two bearings and inspect the clutch/pressure plate.

 

[ruffdog]

If it was the throw-out bearing, I would think that the grinding would increase/decrease with engine rpm (it doesn't per OP). It sounds like the grinding increases as the speed increases between the clutch plate and the pressure plate. Is there a broken spring or other clutch part grinding between the two pieces?

 

[LincTex]

If it was the throw-out bearing, I would think that the grinding would increase/decrease with engine rpm (it doesn't per OP).

That is CORRECT - the throw-out bearing always runs at the same speed as engine speed., This noise does not.

It sounds like the grinding increases as the speed increases between the clutch plate and the pressure plate. Is there a broken spring or other clutch part grinding between the two pieces?

That's the strange thing - it sounds like teeth of a comb rubbing - not metal grinding sounds.
Take a plastic hair comb and run the teeth across a sharp edge, and that's what it sounds like.

I wonder if something came loose from the clutch disc.....
but when it is in gear and the ground speed is at 0 MPH, (the input shaft is also at 0 mph) -
- that is when the noise is the loudest....
when the disc isn't spinning at all.

 

[johnsonauto]

That is CORRECT - the throw-out bearing always runs at the same speed as engine speed., This noise does not.



That's the strange thing - it sounds like teeth of a comb rubbing - not metal grinding sounds.
Take a plastic hair comb and run the teeth across a sharp edge, and that's what it sounds like.

I wonder if something came loose from the clutch disc.....
but when it is in gear and the ground speed is at 0 MPH, (the input shaft is also at 0 mph) -
- that is when the noise is the loudest....
when the disc isn't spinning at all.

It is posible that when they did the clutch, someone put the pilot bearing in the wrong place. It goes in the flywheel, not in the crankshaft ( but it will fit in the crank) then when you push the clutch in the input shat will flop around a bit as it is not suported by the pilot bearing .

 

[ovrszd]

It is posible that when they did the clutch, someone put the pilot bearing in the wrong place. It goes in the flywheel, not in the crankshaft ( but it will fit in the crank) then when you push the clutch in the input shat will flop around a bit as it is not suported by the pilot bearing .

Never heard of that. Anxious to hear a solution.