Snow Question about PTO shafts

[Old School]

I have a b2650 front mount snowblower that I've used for several years with no issue until the very last snowfall last year. The mid pto shaft goes from the transmission to a subframe mid shaft, for lack of better words. The mid shaft mount broke and needed to be welded. It appears the mount broke because the mid pto shaft isn't perfectly balanced. The mid pto spins at speeds up to 2000 rpms. I tend to run the engine at 3/4 throttle because it feelings like I'm over driving the pto and snowblower at max power.

Is it normal to get pto shaft vibrations at those speeds? Am I over driving the mid pto causing the vibration which lead to the mount braking?

Are pto shafts normally balanced and how do you go about balancing a 2 piece pto shaft?

Before I go out and buy a new mid pto shaft I figure I'll ask these questions first. Thanks

 

[wolftree]

I would price the new shaft for comparison first. Then look in yellow pages for "drive shaft balancing". If none appear in yellow pages, look under "Truck Springs" and they may point you to someone in your area.

 

[droptop]

2000 rpm isn't all that fast to generate a vibration unless it's way out of balance. If I had to guess, any vibration present is caused by misalignment or the shaft being bent.

 

[dougtrr2]

I just wonder if the vibration is why you thought you were overdriving the setup?

Take Care,
Doug in SW IA

 

[Baby Grand]

What Causes PTO Vibration?[/url]

2000 rpm isn't all that fast to generate a vibration unless it's way out of balance. If I had to guess, any vibration present is caused by misalignment or the shaft being bent.

That sounds right to me. Have you checked for wear? Slop in the bearings will also cause vibration when the shaft goes off-center. Also, be aware that there is a correct and incorrect way to install the yokes (phasing):

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng5241

 

[Old School]

I would price the new shaft for comparison first. Then look in yellow pages for "drive shaft balancing". If none appear in yellow pages, look under "Truck Springs" and they may point you to someone in your area.

I called a couple driveshaft shops and they said they didn't have the equipment to balance the shaft because of the proprietary 10 spline yokes.

 

[Old School]

What Causes PTO Vibration?[/url]

That sounds right to me. Have you checked for wear? Slop in the bearings will also cause vibration when the shaft goes off-center. Also, be aware that there is a correct and incorrect way to install the yokes (phasing):

What Causes PTO Vibration?

Thanks. That article is helpful. I'm thinking the shaft might be bent and thats why the guy sold it. I ordered a new shaft yesterday but I'm still not done trying to problem solve the one I have.