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.