Kubota M9960 Rides Rough Please Help

big bubba · Sep 16, 2015

14 lbs is what i go with in my loaded (3/4 full) rear tires

farmer2009 · Sep 16, 2015

Some useful reading. It also shows how to calculate the correct pressure for you specific tractor.

The right air pressure for your ag tires or tractor tires with Michelin

BAP · Sep 18, 2015

Did you figure anything out?

brushcutter · Sep 21, 2015

Haven't had much free time but did mess with it this weekend. The rear tires had 15 psi in them when first checked. Let out some water air psi to 12. Didn't notice much difference. Let more water air psi to 8. Seemed to be a little smother going to take a little more water out and air the tires bask up to 14 psi and see what happens.

MessickFarmEqu · Sep 22, 2015

my bet is they are bias tires, the other tractor is radials.

art · Sep 22, 2015

I don't think you will need to add air!

brushcutter · Sep 22, 2015

Taking the tractor into an ag tire service center today. We are going to play with water air levels and see what happens. Talked to a guy yesterday in town that has an M8560 and he said his tractor rides rough. He only uses his to put out hay a shred so it hasn't gotten to be a real problem but he said it is definitely the roughest tractor he has owned.

Just dropped it at the tire center and the tire guy said I was wasting my time. This is the 4th Kubota he has had at his tire shop in the last 6 months complaining it was rough. He said one of the guys had him put on different types of tires and it still was rough.

daugen · Sep 22, 2015

Well I guess this begs the question whether all tractors this size ride "rough" or is it just Kubota? Do the JD guys complain of the ride also?
Nobody is bashing brands here, just trying to figure out what works best.
Until the cabs have suspensions, which many larger tractors do, I can only wonder what could be the difference from brand to brand vs psi or tire construction
I was totally disappointed with my stock Kubota seat and the dealer would not install a Michigan seat in it because of the warranty. Well it's out of warranty now so I might try that first, plus lower the rear tire pressure a little.

brushcutter · Sep 22, 2015

Ya not bashing Kubota. We have a M9540 that has been a great tractor. That's why we bought the 9960. We also have a Kubota L3800 and Kubota RTV that all works great. We had a Kubota M9000 before the 9540 but traded it in on the 9540 because we made the mistake of not getting MFWD to run the loader. Before that we ran a JD 4440 and 4020. We had a Ford when I was a little younger but can't remember the model number on it. It seems to be a problem with Kubotas 60 series cab tractors that run rough. Talked to a Kubota rep and he said make sure the rubber grommets have not collapsed causing the roughness.

Tx Jim · Sep 22, 2015

IMHO color(brand) of tractor isn't contributing factor of ride-ability. Length of wheelbase,weight of tractor,type of tires(radial or bias-ply),diameter of tires,air pressure in tires and seat suspension all contrite to ease of ride & finally location of seat in relationship of rear tires. If tires are loaded especially over 75% which is most manufacturers recommendations could also contribute to a rough ride.

big bubba · Sep 22, 2015

since you're having it looked at, my take would be to closely look at the fluid level in rears. 2/3 to 3/4 full. then play with air pressure.

farmer2009 · Sep 22, 2015

Tx Jim said:
IMHO color(brand) of tractor isn't contributing factor of ride-ability. Length of wheelbase,weight of tractor,type of tires(radial or bias-ply),diameter of tires,air pressure in tires and seat suspension all contrite to ease of ride & [bold]finally location of seat in relationship of rear tires.[/bold] If tires are loaded especially over 75% which is most manufacturers recommendations could also contribute to a rough ride.

I'm wondering if you aren't onto something there. Remember the 66 & 86 series Internationals. The seat was moved on the 86 series forward I believe. That messed with the weight distribution and the 86 series road a lot rougher than the 66.

kuboman · Sep 22, 2015

Seating position can be a big factor to how the ride is. The farther ahead you site the rougher the ride. Also add weight to the 3pt and your ride will smooth right out especially with a loader. And let as much air out of your tires as you can.

brushcutter · Sep 22, 2015

Tire guys filled it to just under 3/4 full and we went from 14 to 6 psi will little diffrence in ride quality. Checked the rubber grommets under the cab and they all looked okay. Got the names for the other 3 guys who had brought in their kubota to him because of the rough ride and had no luck in proving the ride. Now trying to work with my dealer to get a m135gx. Also looking at a jd 6130d or 6125m. I know thats a big jump to an M but why we are looking thought we should look at everything.

kuboman · Sep 22, 2015

Filling tires with liquid will degrade ride quality. With a tire 3/4 full of fluid limits the flex in the tire because of the small volume of air.
Shed the liquid add cast and add just enough air to limit tire squat.

redman135 · Sep 23, 2015

At 14-16 psi AND no weight on the 3ph those tyres are too hard. I would be running then at more like 10 - 12psi. You will find that as little as 2psi can make a large difference.
If all else fails try running with ballast on the 3ph, or leave an impliment on all the time, as this will help smooth the ride.
On the jd6920, set up for the mower (20psi) then hitching the rake on the ride is rough as the rake is much lighter and runs best at 16psi. These tyres are 75% loaded.

brushcutter · Sep 23, 2015

Have 2 sets of rear weights on the tractor and have tried psi down to 6 with no improvement. Most of my work with the tractor is with implements attached to the draw bar. Sherreding with bat wing, sprayer, no till planter etc... Thanks for all the suggestions but I think the rough ride comes from the dimensions and seat placement of the tractor. Between a Kubota m135 and jd 6130 wich one do yall think would be better to replace the 9960?

art · Sep 24, 2015

They do make tractors smaller then the 135! They also have the full power shift the same as the 135. I wonder if your seat is working right? Did you get the air ride seat?

farmer2009 · Sep 24, 2015

Of those two choices I think I'd rather have the JD 6130. But also don't forget about New Holland and Case IH. From what you listed as chores for it I think the Kubota is lacking the weight.

How much wheel slip do you have pulling your drill?

brushcutter · Sep 24, 2015

No air ride seat yet. The dealer wants 700 dollars to install one and if we are still not happy with the ride and trade in the tractor we would have to eat the 700 dollars. The other reason no air ride seat yet is the air ride will make the bumps a little easier on the operator but the tractor is so rough we have trouble keeping our gps system mounted in the cab. So an air ride seat would make our backs hurt a little less but not help some of the other problems the roughness is creating. Yes they make smaller but if you look at the specks on a Kubota the M100 and M110 they only have a 95 in wheel base vs a 105 on a M126 and M135. If wheel base is our problem then we want the biggest they have. That and the price is not that great between the tractors. JD 6130D’s only have a 96 in wheel base that makes me a little worried about their ride. We are defiantly going to drive them both before we buy anything.