Bush hog/Rotary mower question

[Ramblin Rose]

I've got an 8ft pull behind bush hog that chatters and vibrates when making a semi sharp to sharp turn, drive shaft is tight and u joints seem to still be in good shape. Any ideas on what this might be and how to fix it?

 

[backhoeboogie]

Lots of possibilities. Most times the blades are not balanced in weight. Have had wire around one arm on one side that threw the balance off, but not bad. Could be a bad bearing on one side.

Balance is the key most of the time.

 

[Hook]

Could it be swinging to one side and the tire is rubbing on the hog?

 

[Rafter S]

I know you said the U-joints are tight, but since you said it does it only turning I still think it's the U-joints. They'll chatter if you turn too tight even if they're brand new.

 

[highgrit]

The drive shaft on the mower is a inch or two to long. As you turn the PTO shaft gets shorter and puts pressure on the U-joints.

 

[dun]

Any of those 3 would be the cause. I've run into the shaft shortening most frequently and the hitting the tires deal second most often. Blades out of balance only once that I wasn;t aware of when I picked up a section of 14 gauge hotwire the previous putz had left laying across a field. By them time I caught it the other blades was also caught up and the clutch started to slip.

 

[Ramblin Rose]

Ok thanks for the ideas, first time I've ever used this forum and can see its gonna be handy. I'm gonna start with the u joints and could be a balancing issue but the drive shaft length I don't believe is the issue, it slides in and out good and has plenty of travel. But will definitely explore all options.

 

[D2Cat]

Your U-joints may be tight, but you could have a slight bow in the shaft. When you're going straight look back to see if you can see the shaft oscillating some. That slight bow can be fine when going straight, but is amplified when turning.

 

[dun]

If the blades are out of balance it will do it all the time, not just when you turn.

 

[John SD]

:welcome:

Also make sure the two pieces of the drive shaft are "in phase".

The U-joints on the tractor PTO and the mower gearbox must operate in the same "plane". The U-joints in the middle must operate 90 degrees off in another plane.

Any other arrangement is likely to cause excessive vibration at certain speeds and angles. Not sure I'm explaining this well