Mowing M9540 Pto vibrates

[Mike Reid]

I hooked my 6’ brush hog up to my M9540 and it basically shakes and vibrates my tractor so bad it feels like the windows are going to rattle out. If I hook the same mower up to my M6800 it mows and operates smoothly, anyone have any thoughts?

Typically my M9540 is a dedicated to my 15’ batwing but I was noticing some vibrations and I knew my right wing driveline was in bad shape so I hooked up my 6’ mower and the vibration was unreal!! I put a new drive line, blades and stump jumper on the 6’ mower and the vibration was less but still very noticeable! Any help would be greatly appreciated!

 

[JWR]

Intriguing to say the least. Being smooth on the M6800 vindicates the mower. Logically it can't be the mower nor the driveshaft to the mower. The fact that you had vibration using the batwing that led to this investigation in the first place certainly points to the M9540 and only the M9540.

You say the 'right wing driveline was in bad shape' -- Are you meaning 'batwing driveline was in bad shape' or just the right side subset?

I do not own a 9540 so cannot speak from direct experience but I am an old retired engineer with a lot of vibration analysis background and many years tinkering with tractors.
First thought is that the driveline issues with the batwing got bad enough that they damaged the bearings for your 9540 PTO shaft. I assume you have grabbed the PTO shaft and tried shaking it laterally, up/down etc. Does it feel loose? In disconnected status do the bearings feel OK ? Roll easily with no lumps and catches? If you run the PTO in a no-load mode (e.g. with no implement connected but running the PTO at rated rpm) does it rattle or make excessive noise ? Compared to the M6800?

Second thought: Is a high rpm PTO invloved here like 1000 rpm? If so go back to 640 rpm and check things.

That's about all I can suggest

 

[RickB]

Check the 9540 PTO output shaft to see if it is bent.

 

[sandyc]

Check the u joints on the drive shaft to the mower. Out of phase?

 

[JWR]

Check the 9540 PTO output shaft to see if it is bent.

Excellent idea.

 

[JWR]

Check the u joints on the drive shaft to the mower. Out of phase?

Can't be. He already tested it on another tractor with smooth results. Any power train phasing issue (which only exists due to faulty assembly of U-joints connected by a drive shaft) moves with the implement.

 

[ruffdog]

Are both tractors running the same pto rpm?

 

[SDT]

Check the 9540 PTO output shaft to see if it is bent.

Bingo, Rick.

SDT

 

[ovrszd]

On the 9540 it's not possible to mistake the PTO speed 540 versus 1000.

The shaft is swapped to change speed. Six spline versus twenty spline.

I'm with Rick in regards to handling the shaft looking for bearing failure or bent shaft.

 

[ruffdog]

On the 9540 it's not possible to mistake the PTO speed 540 versus 1000.

The shaft is swapped to change speed. Six spline versus twenty spline.

I'm with Rick in regards to handling the shaft looking for bearing failure or bent shaft.

It is possible then that the different gears/shafts (internally) could also have an issue, not just the swappable pto shaft.

 

[5030]

Typical. Post it on OTT and if you don't get the answer you 'want' post it on here. I explained in detail what to do on OTT. Not wasting my time explaining it on here other than to say I didn't realize the 9540 was an exchange shaft 540-1000 setup (like my M9's are) but then the M9's also had the little optioned internal shift speed selector.

Of course there is more to the story than the op is alluding to like how his kid abused the tractor while chopping. Guess that wasn't germane of he got tired duplicating his comment and left that part out..............


Duh

 

[JWR]

OK, what is "OTT" ?

 

[ovrszd]

It is possible then that the different gears/shafts (internally) could also have an issue, not just the swappable pto shaft.

Yes.

I only explained the shaft swap to clarify it's impossible to be running the 540 impliment at 1000

 

[ovrszd]

OK, what is "OTT" ?

Orange Tractor Talk.

Daryl is directing us to a website that most are not members of.

 

[5030]

Yes.

I only explained the shaft swap to clarify it's impossible to be running the 540 impliment at 1000

Not really Richard. I use my 21 spine, 1000 rpm stub with a 21-6 clamp on adapter on it to run lower torque intensive implements like a rotary rake or a grain leg all the time. I run my 1000 21 spine stub at 1540 engine rpm which gives me a 540 spin on the 1000 rpm stub. My tach is even marked as such (by me).

Far as OTT is concerned, it's a Kubota Tractor only website and there are a number of regulars on here that are also on there, SDT included, among others including me. One thing nice about OTT is, a number of registered regulars on there happen to be Kubota certified technicians, so if you have a tech question and post it there, chances are it will be replied to by a knowledgeable technician and not someone taking a wild guess.

Very handy when dealing with more complex mechanical issues. Consequently, if you are a Kubota owner like me and have any issues, that is the forum to look at. In no way am I promoting it, I have no dog in the game and no vested interest in the forum other than I'm a registered member. Unlike here, there are only 3 mods for the entire forum, one freelance and the owner and his partner and they prefer a self moderating forum and it works fine 99% of the time. If I have a Kubota related question, I always post it there, not here.

What I find interesting is, a poster will ask on there (OTT), get an informative answer from an experienced user or tech and then post the same exact question on here, it's like they don't like the response on there, so they come here and get basically the SAME answer.

All I was alluding to. keep in mind I only own Kubota large frame tractors. No other brand..... and when this forum was started by MC, many years ago, it also was a Kubota only forum.

 

[5030]

To reinterate, I've had my 2 speed PTO apart in the past. I've removed it from the back transmission casting so I know what it entails and what to watch out for when removing and reinstalling it and I explained that in my OTT comment and I'm not going to rehash it here because it's somewhat involved.

I will say that the entire unit is self contained in the back cover casting (except for the wet pack power transfer shaft) and all the parts, gears, pre load shims and seals are easily replaceable with just handtools and some common sense and a tube of 3 bond for reassembly.

 

[ovrszd]

So Daryl, what is your prognosis?

 

[5030]

Read his post on OTT and he said his kid was using the tractor to brush hog and ran into some 'stuff' that stopped the brush hog (more than once I might add) so I believe he broke some of the gear teeth in the pto powertrain from shock loading it. Was suggested that there would be metal in the filters (on the ott site) but I said the teeth would be laying in the bottom of the rear gearcase, below the ring and pinion set when he pulled the pto cover off, not in the filters. The gear teeth in the pto drive are helical, not straight cut.

I suggested before taking the pto section off, to remove the implement entirely from the tractor and engaging the pto and seeing in it was still shaking. My reasoning on that was an impact load on a chopper hard enough to stop the pto at speed could be in the chopper itself and I was scratching my head as to whether the slip clutch on the chopper was ever maintained properly as in slipped ever. I break my slip clutches every spring as a matter of maintenance.

He never responded one way or another on here or on OTT. If the wet clutch pack lock pressure is correct, it locks with enough force to break the gear teeth. Shock loads are meant to be absorbed by the implement slip clutch, no the pto itself.

Where it stands.

People pose questions and never reply quite often as you know Richard. Easy to take apart (it's heavy) and easy to repair too. I would imagine the gears are expensive as most Kubota parts are but a bit of common sense and common tools are all that is required.

As I stated, mine is a 2 shaft as well but Kubota did offer a fork shifted 2 speed in the M series. Never seen one though.

 

[5030]

Bingo, Rick.

SDT

I will say that to bend that shaft and not fracture the housing or internal gear carrier would be a miracle. No way you could bend that shafrt For one thing, it's not very long, overall length is about 9" max. and it's heat treated too. It only goes into the gearset (internal splined) and is retained by a snap ring or in the case of a twin shaft, retained by an external snap ring. You'd fracture the internal cast spider first and the pto would be totally inoperative and leak like a stuffed pig.

 

[RickB]

I will say that to bend that shaft and not fracture the housing or internal gear carrier would be a miracle. No way you could bend that shafrt For one thing, it's not very long, overall length is about 9" max. and it's heat treated too. It only goes into the gearset (internal splined) and is retained by a snap ring or in the case of a twin shaft, retained by an external snap ring. You'd fracture the internal cast spider first and the pto would be totally inoperative and leak like a stuffed pig.

They can and do bend and twist, often without any collateral damage or leakage. I have no idea if this one is or not. I suggested that the shaft be checked to see if it is bent, which is an easy check before tearing into the PTO unit. Preconceived notions about the nature of a failure can lead to wasted time and needless expense.