870 Dual Stage Clutch Question

[gthawus]

Hi! JD Model 870 tractor 1994, 3500 hrs. Could someone help me understand what's going on with my dual stage clutch? Over the last year or so I've had to adjust the pedal linkage out several times in order to get the pto clutch to disengage. Now I seem to be at the limit of the adjustment range. Can't maintain the minimum 5/8" pedal freeplay and still engage the pto, without gear grinding. In other words, the traction clutch works OK but action is at the very top of the pedal postion and I can't push the pedal down far enough to disengage the pto clutch. John Deere clutch parts seem to be very expensive. For what I might need is there another source? Thanx for any advice, gthawus

 

[Tx Jim]

I'll certainly agree that the complete clutch kit is expensive LVA801352 DUAL CLUTCH ASSY ADD 2,371.20 USD . It possible that the one or both of the clutch plates are warped causes the pto clutch to drag.

 

[gthawus]

Interesting!! Thanks, Tx Jim. My first thought is that a plate warping would be a one time event. Thereas, I seem to be having something deteriorate over several months. I can see by the cleaner threads of the turnbolt in the pedal linkage that I've adjusted it out a half dozen times about 1/4". Looks like the way to go is to pull the tractor apart and proceed from there. I'm a little reluctant to jump into that without trying to gather as much info and ideas as possible.

 

[jd110]

Just curious, is this the original clutch at 3500 hours? If so, then you have done good for not having clutch issues before. This adjustment issue is a drawback to the dual stage clutch. The transmission clutch typically wears faster than the pto clutch. You have to adjust the free travel to keep transmission clutch in adjustment and there is no easy way to adjust pto to keep them in sync.

It is possible, although not easy to adjust the pto clutch from the outside without splitting the tractor. If you remove the plastic cowling panel from under the steering column on the right side, you will expose a screened cover on the side of the clutch housing. Remove the cover and there are three adjusting screws spaced equally around the clutch.(item #9) The clearance between the head of the bolt and the clutch plate (#8) should be .060". As the transmission clutch wears, the gap gets larger. If you loosen nut #7 and turn each bolt in to get the .060" clearance (.055" may be better), the pto clutch will be able to release properly again. The clutch assembly needs to be rotated to the proper position to be able to access each adjusting screw. By the time you run out of free travel adjustment again, the clutch will most likely need replacement then. This procedure will delay the expense of a new clutch for a while. Typically when that time comes, you can rebuild the clutch pack instead of replacing entire unit. Average repair parts at this time runs around $1100 - $1200. Typically replace items 3, 4, 5, 6, 8, and 24 as well as pilot bearing. Good Luck!

 

[gthawus]

JD 110....That's Got It!!! Followed your instructions and I'm back in action. The only downside is the grass is in it's summer spurt and I've got a lot of catching up to do. The clearance between the cap bolt and plate was at least 1/8" and I estimate the traction disk to be about 1/4" in thickness which the manual says is right on its minimum. So, if it'll last until winter that'd be great. Yes, it's the original clutch and I do a lot of pasture shredding with rough terrain so lot's of shifting. As I look back, 3500 hrs doesn't seem like a lot but I guess that's a good example of time slipping by. Been a really good tractor. Thanks and Aloha, gthawus