2380 wont turn bushhog fast enough to cut

[fraz830]

I need some help my 2019 bx 2380 wont turn my bushhog fast enough to cut, it worked fast enough last fall, now this spring the problem started, I changed the gear oil in the cutter and replaced the shear bolt. I also checked the stump jumper and blades all moving freely. the bushhog is a unknown brand, and not hearing any grinding and when i increase the speed/rpm of the tractor for the pto its does not increase the speed of the blades... help any ideas. both the belly mower and front loader seem to working fine..

 

[BigG]

How big is the bush hog? How do you know the speed of the blades? Are you engaging the PTO while at idle and then speeding up the PTO? Did you remove the blades to sharpen them? Does the mower work any better at a low ground speed?

Do you have another implement to attach to the PTO to check if the clutch is engaging correctly?

 

[Dave_eng]

If the shear bolt is intact then a key on the cutter must be sheared off and its only some friction is driving the blades.

The key could be on the input shaft pto yoke or the output shaft of the cutter.

Dave

 

[fraz830]

I removed the stump jumper and blades are rough, but the key on the shaft is good . this a 4 foot older bush hog. last year when I used it i could tell as increased the rpm for the PTO I could hear the speed increase on the bush hog. I not hearing that now

 

[fraz830]

This is a 4 foot bush hog. Yes I engage at idle and then increase the rpms. I removed the the stump jumper yesterday and the key on the shaft is good, the blades are crappy buying some needed new blades. But when increase the the rpms they don't seem to increase the speed of the bush hog, wondering if there is something wrong with rear PTO
and no I no other attachments for the rear PTO

 

[BigG]

When you say that you replaced the shear pin I am going to guess that you hit something. That being said I would remove the PTO shaft from the tractor and block the stump jumper from turning. I would then try to turn the PTO shaft. Without the noise of the tractor I would guess one of the two shafts inside the gear box has broken or the teeth on one of the gears is stripped and you will be able to hear something grinding.

The alternative is to open up the gear box and inspect for damages.

 

[fraz830]

No I did not hit anything, this was an older bush hog I purchased my tractor, I asked a Mechanic at my local Kabota dealer poss. causes, he told me the same things to check, I put a pry bar on the PTO shaft near the ujoint and tried to turn the blades assy and would not turn. Since this was a used bush hog I checked the shear bolt found that it was cracked but not broken so I replaced it, I also service the gearbox and did not find any metal shaving. I was wonder is one of the PTO (the rear) could have a problem and the mid PTO for the belly mower could be ok. This started this spring, I did not use the PTO over the winter, just the front end loader to move snow a little, and last use in the fall it was all ok. Thinking it might be something Internal power going to the rear PTO.

 

[200mph]

Since the cutter is OK, either your judgement of RPM is wrong or you have an issue with the tractor PTO system.

Since your tractor appears to be 1 year old the warranty may still be valid and I'd let the dealer handle it. They should be able to determine if the PTO RPMS are not consistent with engine speed.

 

[skeets]

Yes if you have a warranty USE it. One more thing to check and maybe you have done it, check on your tac and see where it shows the mark for 540 RPM on your PTO, as I remember your tac should read about 2500 RPM or almost WOT,,, just a thought

 

[dalola]

540 PTO RPM on a BX is 3200-3400 engine RPM.

You should be able to engage the tractor rear PTO with nothing attached, and visually note RPM increase with throttle, via the PTO shaft.

Sounds like a faulty gearbox or some other issue on the cutter.

 

[Tornado]

I would check the pto of the tractor and see if it is actually increasing in speed as you throttle up. You can do this with just basic observation. One idea I had to perhaps check it is put a zip tie around the pto shaft, so you have a little excess sticking out 1-2 inches. You can use that as a little visual, or even could carefully put a stick down near the shaft and gauge the speed by listening to the zip tie strike the stick. Increase RPM then put stick dow nagain, see if you can tell its actually spinning up faster.

I tend to be more suspect of the cutter than the tractor PTO. Have you opened the gear box up and inspected it thoroughly ?

 

[RCW]

A few years ago I did some governor work on my old 'Moline and had to figure out engine RPM at WOT.

Used rear PTO as an indicator with a non-contact digital tach from Amazon.

Small piece of reflective tape on PTO shaft, then "point and shoot" with the tach.

$20 well-spent....got me close enough for that old tractor...I think it was 520 RPM at the PTO and I don't use rear PTO at all.

Could do the same with your rear PTO to see if you're close to 540 RPM.

https://www.amazon.com/digital-tachometer/s?k=digital+tachometer

 

[skeets]

I am just wondering, if the 80 is like my 60 the PTO lever has 3 places it can be in. Just rear pto and mid pto and the 3rd is for both mid and rear I dont know what you would use that for, but I wonder if maybe the selector is in mid and rear PTO spot. Could that make a difference I dont know?

 

[fraz830]

Thanks for all the Feedback everybody, I have check into the items suggested
this weekend. I will let you know Saturday or Sunday... thanks...:

 

[Palmettokat]

No I did not hit anything, this was an older bush hog I purchased my tractor, I asked a Mechanic at my local Kabota dealer poss. causes, he told me the same things to check, I put a pry bar on the PTO shaft near the ujoint and tried to turn the blades assy and would not turn. Since this was a used bush hog I checked the shear bolt found that it was cracked but not broken so I replaced it, I also service the gearbox and did not find any metal shaving. I was wonder is one of the PTO (the rear) could have a problem and the mid PTO for the belly mower could be ok. This started this spring, I did not use the PTO over the winter, just the front end loader to move snow a little, and last use in the fall it was all ok. Thinking it might be something Internal power going to the rear PTO.

I doubt the tractor's rear pto has an issue. But when you use the pry bar on the pto shaft as you say above...was the shaft attached to the tractor? If so the tractor's pto was holding the pto shaft from turning, not the mower most likely. I know you say the key on the gearbox was fine, my guess is you don't have the jumper pan reinstalled correctly, it is tight by the nut holding it on is tight enough to make you think it is fine but it is not strong enough to hold up to the load of the blades weight or it being used.

 

[GreensvilleJay]

re: tried to turn the blades assy and would not turn

disconnect PTO shaft from tractor
manually spin PTO shaft by hand
you should be able to spin the blades
I can do this on a 6' mower( yeah,take a bit of grunting...)
a 4' mower should be easy....

if the blades do not turn, you got 'mower deck' problems, not tractor issues.

some possible causes...
PTO Ujoint key sheared
'something' busted inside gearbox
37' of barbedwire wrapped around blade hub

 

[200mph]

What was the final outcome of this?

 

[PitViper]

I am just wondering, if the 80 is like my 60 the PTO lever has 3 places it can be in. Just rear pto and mid pto and the 3rd is for both mid and rear I dont know what you would use that for, but I wonder if maybe the selector is in mid and rear PTO spot. Could that make a difference I dont know?

Running a belly mower and a PTO driven grass catcher at the same time would be one application for running both belly and rear PTOs at the same time.

 

[PitViper]

Nobody suggested calling up a buddy and hooking up the bush hog to their tractor.

 

[skeets]

I never thought about running the MMM and grass catcher at the same time,,, good call,,,,, So Yall got a viper huh,,