Rotary Cutter JD 5105 tractor with JD MX 6 rotary cutter quits cutting

[texasjohn]

I admit it... am embarrassed by this question, I should be able to figure this out myself but am stumped. This is a friend's equipment, very well maintained, in fact, by dealer. She's owned equipment 5+ years, all she does with it is mow grass, she knows the equipment and how to mow, she never disconnects rotary cutter.

Net... the MX6 rotary cutter/shredder/brush hog simply quits cutting grass for no reason I've been able to figure out.

Details:

• tractor starts and runs perfectly, RPM's at 2300, no change in engine sound or cutter sound that I can hear when it stops cutting.
• ground is level, grass/weeds to be cut are light, 1.5 foot high at most, it's EASY cutting, no brush, no stumps, no rocks. Cutting height is about 6 inches. Cutter rear wheel is lightly rolling on the ground
• ground speed is such that I can keep up at a brisk walk
• I watched yesterday as she started cold tractor, warmed it up for about 4 minutes, engaged PTO, brought speed up to 2300 RPM, cutter blades clearly rotating at speed, let out on transmission clutch and started rolling. All was perfect for maybe 100 yards, cutting as expected. Then, it stopped cutting while rolling along. Operator took no action to cause this to happen, PTO lever still engaged, nothing unusual/different about terrain to cause it to stop cutting. No grass buildup under cutter.
• Grass was pushed over as blades rotated over it, but it was not cut.
• I felt clutch on cutter, absolutely no heat. It was not slipping, nor any reason for it to be slipping.
• cutter blades inspected and reasonably sharp, blades themselves are free swinging and extended, not folded back or locked up. Cutter itself rotates by hand, gear box not excessively hot, rotates PTO shaft on tractor (engine off, PTO disengaged), thus not locked up.
• all PTO plastic guards are in place so I could not directly observe PTO shaft RPM, but cutter was still rotating when driver stopped to let me observe path of uncut grass/weeds.
• I removed protective shroud over cutter gear box and clutch. All shafts and splines appear properly mated, nothing disconnected, worn, loose.
• I observed cutter PTO shaft connection to tractor PTO shaft. All appeared properly mated/connected. I removed protective plastic guard, disconnected PTO shaft...it uses a slip collar....it was inserted approximately 3 inches onto tractor PTO shaft. Splines aligned properly, no heat at this PTO connection. I reconnected PTO shaft, it made a positive connection sliding onto shaft and clicking strongly to make the connection. With the collar properly in place, I could not pull the cutter PTO shaft off, or find any play in the connection itself... a good thing!!

So, am confused about why it would simply stop cutting. This has occurred on multiple occasions. It seems to start off OK then at some point just stops cutting the grass.

The answer must be obvious, but I haven't figured it out

 

[JoeinTX]

To read this, it sounds like the PTO simply quits spinning the cutter? No?

Problem, if so, looks to be the tractor and not the shredder.

 

[9973720wb19]

are the belts on the mower slipping when they heat up - maybe they are stretched and needs new ones

 

[Lineman North Florida]

Have you tried another implement such as a tiller on her tractor, that way you could narrow it down to which piece of equipment is failing, or either hook her mower up to your tractor, I'm betting on something not being quite right with the PTO on her tractor. Keep us posted and good luck.

 

[texasjohn]

No belts on the mower.... drive train is..tractor PTO to cutter drive shaft via slip coupling (no pin thru it)... drive shaft to slip clutch...to gear box where 90 degree change in direction to rotate the cutter blades.

Agree that possibly "something" isn't right with with the tractor PTO...but what could that be?? PTO lever is engaged on tractor...what can slip out of engagement without moving the lever??

My friend has no other PTO attachment... idea to exchange try different shredder or tractor is good.... will have to do if I can't figure anything out....it's about a 15 mile equipment transport.

Any other ideas??

 

[hosspuller]

The tractor has a pto clutch that may be out of adjustment or slipping. Check the linkage first...(easy stuff first before you split the tractor) :thumbsup:

 

[plot man]

Could it be the tractor is low on Hyd Fluid? My tractor did this last weekend while using the tiller. I was in the safe range but started tilling down a fairly steep incline which allowed all the fluid to diasapear out of the sight glass. Added oil to max level and never had another problem.

 

[jdtractor]

hi i would check the slip clutch , they can get out of adjustment ,over time it sounds like the clutch needs to be adjusted. there are specs that the clutch needs to be set at , by that i mean measurements. check the manual on the rotary mower ,it should give you he information you need to look at. the clutch is easy to adjust ,or it is possible the clutch discs are completely gone (worn out) if so they wil need to be replaced.i have done both several times on my rotary mowers from the heavy mwing ive have done over the years. i hope this helps you . good luck

 

[beenthere]

Sounds like the PTO slip clutch needs adjusting.

At least I didn't read anywhere that the PTO drive shaft from the tractor quit turning when the rotary cutter quit cutting.

The operators do need to learn more about this equipment to safely operate it, and hopefully this incident will help them out.

The manual will explain how to adjust the PTO rotary cutter clutch.

Myself, I would remove any chains holding the plastic PTO covers from turning. Let them spin with the PTO shaft and observe if the PTO shaft stops spinning when the rotary cutter stops cutting.

 

[RPW]

Cutter may have a slip clutch but does it also have a shear pin? Tractor should have an indicator light on the dash to indicate engagement. Also try this at idle while in neutral. Slowly engage PTO while observing PTO shaft. If PTO is working shaft will have a slight wobble as you engage. You will be able to see this even with the PTO shrouds in place. Also you should hear the mower spin up. Kind of a "wop-wop" sound. I am also assuming that when everything was working you were engaging the PTO at idle and then raising RPM's to operating speed and not the other way around.

Good luck.

 

[Builder]

I like the idea of trying another implement on the tractor other than the mower.
If you can borrow an implement, or maybe it'd be less trouble to buy a cheapo spreader used off craigs list to see if it spins, then resell it when (if) you've determined tractor is healthy. I just sold a 3pt spreader excess to my needs for $125.
If tractor is healthy, then go to the slip clutch.

 

[grsthegreat]

I have seen a few drive shafts on slip clutch equipment that still have shear bolts. the ones i saw had the shear bolt under the plastic shroud up near the tractor end of the drive shaft. they actually had 2 shear bolts up there. i guess its a fail safe system in case the clutch were to fail. remove the drive shaft from the tractor and see if you can turn the u-joint by hand. if the mower starts to turn....its on the tractor side that has the problem.

also, like others stated..could be the clutch. there is no issue with removing the plastic shrouds to observe if the shaft is turning AS LONG AS YOU STAND CLEAR. How else are you going to know. it will be obvious if the shaft turns but the mower doesn't then......

 

[Lineman North Florida]

Texasjohn was pretty thorough in his first post and said he checked the slipclutch and that it was not slipping, I hope they figure it out pretty quick as it's got my curiousity up

 

[texasjohn]

OK... current untried ideas include

1. tractor has PTO clutch internal to tractor case that may be slipping (I didn't know this, thought it was a hard hookup)
2. PTO engage linkage may be disengaging without positive operator action, check linkages
3. try a different PTO device, shredder/post hole digger..I have these and can transport to their place.
4. remove plastic shrouds to see actual PTO and its RPM's while cutting and when cutting stops.

Will work thru these options as time permits... likely not until this weekend.

 

[jenkinsph]

Sounds like the PTO slip clutch needs adjusting.



Myself, I would remove any chains holding the plastic PTO covers from turning. Let them spin with the PTO shaft and observe if the PTO shaft stops spinning when the rotary cutter stops cutting.

I agree with beenthere, very easy to unhook the small dog chains that prevent the plastic shields from spinning to monitor the pto shaft's rotation. No need to remove the shields. If the pto shaft is turning it would have to be the slip clutch needs adjustment. If the pto shaft starts to slow down then look at the tractor pto clutch adjustment.

No need to bring in another implement from 15 miles away.

 

[AKfish]

Gotta be one clutch or the other... Have to believe that the slip-clutch should be warm (very warm) to the touch - if you'd run it long enough.

AKfish

 

[texasjohn]

Clutch on top of blades was NOT even barely warm...no slipping at all of this clutch. Seems that several folks think there is a separate PTO clutch inside the tractor case...OK... I'll investigate that

 

[beenthere]

There is a clutch in the tractor case.
Here is a schematic from jdparts

Also, in the online manual http://manuals.deere.com/omview/OMRE72817_19/?tM=FR
there is a procedure to adjust the PTO clutch in the tractor.

 

[Builder]

I agree with beenthere, very easy to unhook the small dog chains that prevent the plastic shields from spinning to monitor the pto shaft's rotation. No need to remove the shields. If the pto shaft is turning it would have to be the slip clutch needs adjustment. If the pto shaft starts to slow down then look at the tractor pto clutch adjustment.

No need to bring in another implement from 15 miles away.

What if the mower is binding causing the tractor PTO shaft to bind, then causing the tractor PTO driveline clutch to slip? Lots of 3pt implement slip clutches are not maintained properly and they don't work. This would cause the tractors driveline clutch to slip.
Having a known healthy other 3pt implement hooked up to the tractor would eliminate one of the possibilities.

One thing worth considering is the OP stated the mower mows for X feet, then quits. Something could be heating up, then slipping or binding.

 

[texasjohn]

Beenthere, you ARE a SUPERSTAR:thumbsup::thumbsup::thumbsup: Many thanks!!

I didn't know there was a clutch there....you've not only educated me, but given me the ability to address the problem/adjust the clutch with confidence without breaking into the case.... will do.... Isn't the internet wonderful!!

And, the proper manual is on the net... it doesn't get any better than that!!

Now, all I gotta do is make a visit to my friend and see if I can tune things up. The problem simply HAS to be related to the tractor's PTO clutch....