M6800 PTO

[massey4mike]

I have a 2005 M6800 that seemed to have a problem this past winter with the PTO. Using my 6 ft snow blower would make the tractor shake and make a terrible banging noise. This summer, before the mechanic was scheduled to come and evaluate, I hooked up my 5 foot rotary brush cutter and there has been NO problem. My question is; can there be a problem with the PTO if it runs a brush cutter even under a heavy load but not a snow blower?
Spinning the snow blower by hand, under no load, turned up no knocking or tight spots. I have not hooked it back up to the tractor.

 

[Texas Fella]

Most times that one implement shakes and shimmys, and another does not, it is the drive line. Also, you may not be able to "feel" the issue by hand. It is the high RPM of the shaft that causes the issue if it is bent, unballance, or has a bad u-joint (of course you can usually feel a bad u-joint). I would say hook up the cutter (see that it does not shake) and then try the snowblower (assuming it will shake) and if that is so, the issue is with the implement.

 

[rbargeron]

I remember this was a head scratcher last winter. Reading about it today, if the rotary cutter is smooth under load the pto gears and bearings are likely ok. Does the pto shaft for the blower run at more of an angle? Also if the roller chain that runs the auger is loose or worn the chain can try to jump the tops of the teeth on the drive sprocket. That can make quite a nasty bang, bang. Usually, a shear bolt fails. Rolling it by hand slowly would be smooth - trouble would show up under load. As always, prompt cheerful refund if theory is bogus - take care, Dick B

 

[art]

One of the most common reasons for u-joint failure is not lack of lubrication in the joint but on the shaft!

We've seen shafts virtually sieze and take out the rear of the tractor around the PTO or to take out the other end on the machine.

 

[massey4mike]

Thanks for all of your great input! Just to make things clear, everything is well lubricated, there is no chain, the blower has what appears to be a car or truck rear end for a gear box. However, the shaft DOES run at quite an angle down but the U joints are all good. It could be imbalanced. It is an old blower and owes me nothing, I will be looking to replace it!