4020 - PTO clutch finger failure?

[Glen D Anderson]

Good day!

The back story:

I installed a new clutch kit in our early model 4020D 2 years ago(New clutch assy. & discs. along with new PTO bearing & new traction clutch release bearing). Finger heights set using the OEM OTC tool. The PTO clutch linkage was rebuilt at that time with new bushings installed in the control panel stand along with a new detent pin & spring that hold the lever in the neutral position. The linkage was set as per the service manual. Engagement was smooth and the force felt correct. Not too hard, nor too soft.

Fast forward to this summer:

While cutting hay I went to disengage the PTO and the lever was stuck. It would not release. Further investigation revealed the PTO fingers had "welded" themselves to the bearing(flange). I instantly assumed the bearing had prematurely failed BUT after prying the fingers away from the bearing I found the bearing spun freely with no binding or rough spots whatsoever. So I smoothed out the finger tips with a die grinder to achieve smooth engagement, reset the linkage and managed to finish cutting the rest of the hay.

The confusion:

With the PTO clutch in the neutral position the fingers do not touch the bearing which seems to rule out a "riding the clutch" condition. After splitting the tractor and spinning the PTO bearing by hand putting significant axial force on the face I feel no rough spots or signs of binding.


Any ideas as to what would've caused this?

TIA

 

[Tx Jim]

My guess is the poor quality of today's parts contributed to your tractors pto problem. PTO clutch operation on 4020 creates a similar function as driving with foot on traction clutch as throw-out brg is engaged 100% while pto is engaged & engine is operating

 

[Resting Relic]

I'm thinking the PTO clutch must have not had enough free play and the fingers were riding against the bearing just enough to cause the problem. It does seem improbable unless the bearing was bad. But since you state that was not the case it is a bit baffling. I worked on a lot of those in my days at a John Deere dealer and saw many of the those fingers burned right through when the bearing failed. Perhaps the bearing hung up for some reason and by the time you took it apart it had freed itself. If it was mine and you have it apart I'd replace that bearing. Good Luck! John

 

[Glen D Anderson]

I'm thinking the PTO clutch must have not had enough free play and the fingers were riding against the bearing just enough to cause the problem. It does seem improbable unless the bearing was bad. But since you state that was not the case it is a bit baffling. I worked on a lot of those in my days at a John Deere dealer and saw many of the those fingers burned right through when the bearing failed. Perhaps the bearing hung up for some reason and by the time you took it apart it had freed itself. If it was mine and you have it apart I'd replace that bearing. Good Luck! John

Thanks John!

We wondered about the bearing intermittently "locking up" but I've never seen a bearing spin this smooth have a failure like that. I will say that I wasn't impressed with the clutch kit right from the start as the replacement PTO bearing was a sealed unit instead of the factory design with the raised shield that facilitates greasing but we went with it after everyone telling me that the grease-able style is no longer available.

I guess we'll replace the bearing to be safe and pull the seals on the old one and look for signs of contamination or failure inside the bearing that might have caused it to intermittently lock up.

 

[620 John]

Where did you get the clutch kit from??

We put a few kits in from Ag Parts LTD because the discs are better than JD. BUT we had 3 tractors come back a year later because the traction clutch throw out bearing was welded to the fingers. We put them back together with JD bearings and fingers and haven't had them come back. 1 of the 3 tractors was owned by a different customer than the other 2 so I think parts quality was the main factor. Since then we install all JD parts EXCEPT for the discs.

Your scenario is definitely puzzling but when going back together I think I'd try a different parts source.

 

[Glen D Anderson]

Where did you get the clutch kit from??

We put a few kits in from Ag Parts LTD because the discs are better than JD. BUT we had 3 tractors come back a year later because the traction clutch throw out bearing was welded to the fingers. We put them back together with JD bearings and fingers and haven't had them come back. 1 of the 3 tractors was owned by a different customer than the other 2 so I think parts quality was the main factor. Since then we install all JD parts EXCEPT for the discs.

Your scenario is definitely puzzling but when going back together I think I'd try a different parts source.

Hy-Capacity P/N 41410NU2 KIT

I will definitely be removing the seals from the PTO bearing and inspecting for something that could've caused an intermittent locked condition. If no smoking gun is found then I'm in that awkward position of throwing parts, albeit from a different mfg, at it and hoping for the best.

 

[Fixingfarmer]

Where did you get the clutch kit from??

We put a few kits in from Ag Parts LTD because the discs are better than JD. BUT we had 3 tractors come back a year later because the traction clutch throw out bearing was welded to the fingers. We put them back together with JD bearings and fingers and haven't had them come back. 1 of the 3 tractors was owned by a different customer than the other 2 so I think parts quality was the main factor. Since then we install all JD parts EXCEPT for the discs.

Your scenario is definitely puzzling but when going back together I think I'd try a different parts source.

Have also done this also recently new fingers on one that otherwise was new. The Deere ones seemed slightly different shaped if I remember correctly but it was hard to tell as the aftermarket fingers were destroyed and bent the wrong way. In my case it all fit and left I couldn’t tell you what brand it had.

As I think about it more it might have been the 3020 that was here after someone split a year prior and my guess is didn’t turn the pto shaft while pushing the 2 half’s back together and pulled it tight with bolts and broke the broken clutch housing when it popped together where the shaft goes through into the gear you will want to wiggle that shaft and make sure everything is tight. To get to that to actually see you have to split it farther back we ended up with a whole rear half off a doner tractor. But checking pilot bearing and for wiggle would be first and probably even trying fingers. But if it does it again split it farther back and take a look this one they ran for a summer and it started leaking out the transmission shaft seal and quit moving if I remember right as well it wouldn’t shift at least not well. I got lucky in that regard as it led me the rear split first found out we had a big problem. It is a task taking the middle out of it comes to that hopefully you have a forklift or cherry picker at least. Unfortunately there’s no way of visually inspecting even with a borescope that I know of that gear train on the back of the clutch housing I can see that chunk of the cone laying there like it was yesterday at the bottom of the case when it was split. I suppose up through the transmission screen hole would be a possibility as there are holes in the case if you knew where you were going.

When we couldn’t get parts a few years back on a 2510 I started rebuilding what they had on them a couple new disks all new springs everywhere fingers and pins and either clean up the pressure plate if you can’t find one (2510) or buy new (4020 anything normal) it was a good learning experience and I plan on doing the same on grandpas 4020. It was NOT cost effective on paper you can get a complete clutch for 1000 bucks. But everything fit and functioned as it was supposed to. If you check the transmission screen you would expect to find a few filings but this one was clean as it was a clean break.