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

   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #1  

texasjohn

Super Member
Joined
Oct 11, 2005
Messages
6,003
Location
Central Texas, Jarrell
Tractor
Kubota Grand L5030HSTC
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:eek:
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #2  
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.
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #3  
are the belts on the mower slipping when they heat up - maybe they are stretched and needs new ones
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #4  
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.
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting
  • Thread Starter
#5  
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??
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #6  
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:
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #7  
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.
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #8  
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
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #9  
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.
 
   / JD 5105 tractor with JD MX 6 rotary cutter quits cutting #10  
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.
 
 
 
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