Blocking a wet disk clutch

   / Blocking a wet disk clutch #1  

RoyJackson

Rest in Peace
Joined
Nov 17, 2001
Messages
24,890
Location
Bethel, Vermont
Tractor
John Deere 4052R Cab,, Deere 855D UTV, Z920A Zero Turn Mower and assorted implements
I asked this question in another thread months ago...never got a response.

Since my previous tractors (a 670 and a 790) had dry clutches, I always clamped the clutch pedal down (clutch disengaged) during extended periods of setting. Both of those tractors had a tab on the floor board for this purpose.
My current machine, the 4400 with a sync-reverser, has a wet disk clutch. There is no provision for blocking the clutch open and I don't recall seeing anything in the manual about this.
So, for you Deere guys whose tractors have wet disk clutches...do you block the pedal down?
 
   / Blocking a wet disk clutch #2  
i thought most sync-reverser clutches were dry.
 
   / Blocking a wet disk clutch #3  
Wouldn't think a wet clutch would ever have a chance to rust up beings it's coated in oil.
 
   / Blocking a wet disk clutch
  • Thread Starter
#4  
i thought most sync-reverser clutches were dry.

Not since 1998 or 1999...at least on the old 4xxx series and the newer 3xxx series machines.

This is my first "new design" tractor and I'm not familiar with wet disk type clutches. I'm looking for guidance from our esteemed TBN brethren.
 
   / Blocking a wet disk clutch #5  
Agree with Willl... should not have to block a wet disc clutch. It's nice and cozy in that JD20D or C hyd fluid.

AKfish
 
   / Blocking a wet disk clutch #6  
SR clutches are naturally blocked. Without the hydraulic pressure drive they are both (since there are two of them) disengaged. Since they are disengaged, the engine has NO holding power when off. I posted the schematic a few weeks ago.
 
   / Blocking a wet disk clutch #7  
Roy

I have never heard of this practice, disengaging the clutch,, did you have problems-wet environment, past practices? Please enlighten me

Thanks

Art
 
   / Blocking a wet disk clutch
  • Thread Starter
#8  
Roy

I have never heard of this practice, disengaging the clutch,, did you have problems-wet environment, past practices? Please enlighten me

Thanks

Art

If a clutch (not only a tractor clutch...this applies to cars, truck..anything with a manual transmission) and pressure plate are in contact for an extended time, they can rust together. This is especially true in a wet or high humidity environment.
So, one uses a block, clamp or other device to hold the clutch pedal down. I used a clamp on my old 670 and 790 tractors. There was a tab on the floor (next to the clutch pedal) for a clamp. It's my understanding Kubota includes a wood block of some sort for their gear tractors. I don't own a Kubota, so I don't know how it works. I have seen a bracket with a hook on some old Deere ag tractors.

If the clutch disk does rust to the pressure plate, you might be able to break it loose by popping the clutch. Worst case is replacement of the clutch/pressure plate (think $$$$).

When I owned an old Porsche 911S, I stored it during the winter months. I used a tool that is designed to hold the pedal down.

What I wrote applies to dry clutches. As you read in the responses to my question, wet disk clutches don't have this problem. Fortunately, none of my vehicles ever had a clutch/pressure plate rusting problem, but I have seen it from time to time...also read about on TBN occasionally.
 
   / Blocking a wet disk clutch #9  
Same thing can happen with a drive line safety clutch on implements. That's the reason you should loosen-slip-tighten each season. Several people have found out the hard way that the clutch didn't.

I used to use a dumptruck with a hyd driven clutch, blocking the pedal didn't work as it would leak down over time. We normally left the truck parked about 10ft in front of a big stump. It would start in reverse, and backing into the stump caused the clutch to break free. Didn't do my neck any good though...
 
 
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