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

 

[Bob77064]

What size tractors have suspensions?

 

[RoyJackson]

What size tractors have suspensions?

None, to my knowledge. Some have suspension seats though (to ease operator fatigue).

 

[Robert_in_NY]

None, to my knowledge. Some have suspension seats though (to ease operator fatigue).

The large frame tractors from John deere, Fendt and others do have suspension options. John Deere calls theirs ILS (Independent Link Suspension) but these are on 250 hp tractors and bigger. I don't know what the smallest tractor is that has a suspension system available but it wouldn't be cheap.

 

[Grandad4]

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

I'd support what the others have said about tire pressure, Paul. The tires on our tractors do lose air gradually. Sometimes I'll take one on the road and get some bouncing that is cured by adding some air, usually to the fronts.

 

[nspec]

Full size loaders and backhoes from all major manufacturers offer 'ride control' to counter this common problem when large tires are run at high speed. They use electrohydraulics to move the loader up and down very small amounts to counter the bounce and provide a smooth ride and higher speeds. Has been a problem for 30++ years.

 

[Bob77064]

Tractor with suspension 2155 | JCB

 

[leonz]

Nothing like dreaded case of the Hoppsies to ruin ones afternoon;

The only serious way to dampen and eliminate the hoppsies is to-
be sure the rim is centered if the stud holes are greater in size than
than the studs making the alignment of the tapered lug nuts the
issue for centering the rims, OR be sure you have the diamond
style turfs or the square lug turfs on the rears as they are a tire
with very low P.S.I.,tire and a tire with a very low ground pressure
per square inch.


_________________________________________________________________
Once you go flail you never go back:thumbsup::licking::drool:

 

[boggen]

once you start hip hopping, at least for me, i need to slow down almost completely and restart changing back up gears to higher speed.

for me, hip hopping problems are when i have front loader full, or have something on the backhoe.

when finding new R4's for TLB, the higher the PLY was, the more warnings i saw for hip hopping. higher tire PLY rating = rubber does not flex as much.

double check air pressure as well in all tires. it has been awhile since i have had to check air. i want to say 12 PSI? for the 555TLB i have. tractor tires are not car tires were you want 24 to 34 PSI in them. but a much lower PSI. refer to your operators manual.

take tractor out of 4wd or MFWD. this is normally suggest when ever you go out on the road. due to slight difference in how fast front tires turn vs back tires turn when 4wd or MFWD is engaged.

road conditions change through out the year, at least here in central, IL. just from frost heaving, causing the road to crack and buckle in spots. just them slight bumps can really make a tractor start hip hopping.

on many SCUTS, CUTS, and perhaps utitly tractors i have read here on TBN, that when tractors ship out new, the tires are turned in. causing a shorter width wheel base. i doubt it will do much for bouncing. but *shrugs*

 

[sweep]

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.

My NH with ag tires does the same thing but I notice it more in mid range than high range.

The whole front of my tractor just shakes when going down the road both in 2wd and 4wd.

Thought it might be a driveline problem but could find nothing wrong.I jacked up the front end and found no grinding or weird noises and hnaged the fluid and found no metal shavings etc

Mine started out at about 100 hrs but at 190 hrs now it is not getting any worse.

My personal opinion is the tire belts have moved and the tires arenot perfectly round anymore.

 

[Mousefield]

My tractor is 3 1/2 years old and ever since I got it if I go too fast it wants to bounce. Have only had in in high a few times, not worth trying to go faster, the bounce is a killer. All that shaking has to very hard on the tractor. Usually have my backhoe or box blade on as well as the FEL and travel in mid range. Think it is just one of those things you live with.