Tractor "bouncing"

[Thorn Hill]

Great forum, I've used it many times in the past but just joined officially.

I've got a Kioti DK40 with about 250 hours on it. Recently it has started "bouncing" rymthically When I'm driving the on pavement. sort of like one of the tires is causing it. Feels like I'm riding a horse. the tires have fluid in them, and air pressure is about 15 in the back and about 20 in the front. I understand that it's not supposed to ride like a car, but this has just recently started.

Any ideas?

Thanks,
Paul

 

[RoyJackson]

Are you running at a higher speed then before?

The short wheelbase and no suspension of most CUTs tends to aggravate the "see-saw" ride, and higher speed makes it worse.
If I run my Deere 4400 on the road (turf tires, BTW) with the loader but no rear ballast, it'll see-saw quite a bit too...faster I go, the worse it is.

Slow down abit and see if the see-sawing abates. If you have a tire issue, you should still feel it, but to a lesser degree.

 

[IndyIan]

Great forum, I've used it many times in the past but just joined officially.

I've got a Kioti DK40 with about 250 hours on it. Recently it has started "bouncing" rymthically When I'm driving the on pavement. sort of like one of the tires is causing it. Feels like I'm riding a horse. the tires have fluid in them, and air pressure is about 15 in the back and about 20 in the front. I understand that it's not supposed to ride like a car, but this has just recently started.

Any ideas?

Thanks,
Paul

Go faster or slower? Or do you have a heavy rear implement on? I drove an L2950 with good size backhoe down the road and had this happen a bunch of times. I see big TLB's bouncing all the time too.

 

[Thorn Hill]

thanks guys, It gets worse the faster I go, High gear on the highway. Ag tires. Nothing on the back as far as implements. I just don't remember being this bad before. But it sounds like this isn't really atypical for a tractor, right?

Just wanted to throw it out there and see if someone would say my "so and so" was out of wack or there was a bulge in the tire or something like that.

Thanks again.

 

[charleyfarmall]

It's a common problem. It's a combination of speed, wheelbase, tire pressure, and tire compliance. I find R4's worse than R1's. Turf's are similar to R4's. Check your tire pressure first, then see if you can find a slower or faster speed to travel at which will be out of the frequency range that causes the bounce.

 

[Robert_in_NY]

I have found on cooler days or if one of my tractors have sat for a while it will bounce from basically the tires being out of round (think of a flat spot). Once they loosen up the bounce goes away but the first few minutes requires me to go slow. On the road its very noticable because your traveling at higher speeds and on smooth pavement. My big tractor was the worst of all of them but it just took a little patience when first starting down the road cold.

 

[8404]

I got a DK40 with no ballast in the tires and it runs smooth on pavement, but my DK 55 has all the tires full of water and it bounces verry bad on the road so i feel its the fluid in the tires thats causing my bounce., at slow speeds you wont feel much.

 

[RoyJackson]

I have found on cooler days or if one of my tractors have sat for a while it will bounce from basically the tires being out of round (think of a flat spot).

Softer compound tires (softer compounds are frequently used for better traction) to develop temporary flat spots pretty quickly.
One way to minimize that is to increase the pressure while parked or stored.
Although increasing tire pressure isn't (IMHO) really practical for a tractor, it is worth doing if you have a road vehicle you store for the winter (as I did with that old Porsche I had years ago...).

 

[Smallplot]

Just a thought also, if you have been in any mud recently take a good look at the inner rims. We have had mud build up inside the rim of the tires and it can throw the balance off causing the tractor to buck going down the road. This happens quite often with duel wheels because it is so easy for mud to get between the tires, but we have also had mud get stuck to the inside of the rims causing the same problems. Like you said the faster you go the worse it gets.

 

[Robert_in_NY]

Softer compound tires (softer compounds are frequently used for better traction) to develop temporary flat spots pretty quickly.
One way to minimize that is to increase the pressure while parked or stored.
Although increasing tire pressure isn't (IMHO) really practical for a tractor, it is worth doing if you have a road vehicle you store for the winter (as I did with that old Porsche I had years ago...).

Yeah, but your right, not very practical. Too much pressure on R1 Bias tires run on a road will lead to very uneven wear. Radials are a lot nicer but I'm not in the mood to replace all of my tires with Radials just for an improved ride down the road. Any new tractor I buy will come with radials though