Deutz-Fahr 5090G bouncing problem on the road

[john5858]

The 5090G, which he uses for light work, bounces a lot on the road. There is no suspension. The tires are Mitas. The front tire is 380/85/24 and the rear tires are 420/85/34. AC85. My tire shop said that the air pressure should be 30psi and he set them all to 30. I use the tractor for light work and I can use it both on the road and in the field. I need an average pressure, there is no front loader, there is only 400kg weight in the front (note, the image below is taken from the internet)

 

[Deerefarmer]

30 psi is way to much psi for that application. I'd think 15 to 20 psi for that size of tractor to be more than adequate imo

 

[MF CI]

The 5090G, which he uses for light work, bounces a lot on the road. There is no suspension. The tires are Mitas. The front tire is 380/85/24 and the rear tires are 420/85/34. AC85. My tire shop said that the air pressure should be 30psi and he set them all to 30. I use the tractor for light work and I can use it both on the road and in the field. I need an average pressure, there is no front loader, there is only 400kg weight in the front (note, the image below is taken from the internet)

1st of all find another tyre shop. I guess about half their setting would be somewhere near. But find a proper book or advisor to be sure.

 

[Moors Lad]

Tyre pressures as said above are too high - this will certainly make for an unpleasant ride on the road...... Where are you, in the UK?

 

[feilding]

18 to 20 rear,
22 to 24 front
Should solve the problem.

 

[Barleymow]

Are the tyres on the rims correctly , the red dots need to be aligned

18 to 20 rear,
22 to 24 front
Should solve the problem.

 

[john5858]

Are the tyres on the rims correctly , the red dots need to be aligned

As you said, I checked them and when I was going at high speed, I noticed with my eyes that the front wheel was crooked and I told it to the service and when they checked, they accepted that, rims not centering properly on the wheel discs, but he said that this would not be noticeable, when ı look closely, it is clear that the rims are not exactly centered, one side is very close other side is far, there is a difference of mm, especially on the front wheels.

 

[john5858]

18 to 20 rear,
22 to 24 front
Should solve the problem.

I will try what you say, I plan to make the fronts 22 psi and the rears 25 psi. Some say that the tires will be crushed at low pressure, maybe I will remove some ballast from the fronts, it always seems to bounce from the front.

 

[Deerefarmer]

Fronts not centered on hubs will definitely play into your problem

 

[feilding]

I will try what you say, I plan to make the fronts 22 psi and the rears 25 psi. Some say that the tires will be crushed at low pressure, maybe I will remove some ballast from the fronts, it always seems to bounce from the front.

25 psi too high on back, unless you have a very heavy load on back.
Front tyres always need to be 2-3 psi more than back.
Make of tyres can make a big difference. When I had my Deutz first it was on continental tyres, total rubbish, and dangerous on road, very twitchy at 55k and hopeless on ground. Sold them, and put BKTs. Total change in tractor, very bouncy before at any pressure, all bouncing disappeared after replacing tyres. From memory I think it cost me £200 to change.

 

[smcapstick]

I’d do 22psi front, 16psi rear.

Your tyre place sounds like they only know cars.

 

[john5858]

25 psi too high on back, unless you have a very heavy load on back.
Front tyres always need to be 2-3 psi more than back.
Make of tyres can make a big difference. When I had my Deutz first it was on continental tyres, total rubbish, and dangerous on road, very twitchy at 55k and hopeless on ground. Sold them, and put BKTs. Total change in tractor, very bouncy before at any pressure, all bouncing disappeared after replacing tyres. From memory I think it cost me £200 to change.

There is no loader at the front. However, should it be 2-3 psi higher than the rear? The total weight of the tractor is 4.5 tons and the front axle weight is 2 tons, that is, 1 ton per wheel. I thought it would be more beneficial if the pressure in the front was less than the rear. Could you please explain why the pressure in the front should be more?

 

[john5858]

I’d do 22psi front, 16psi rear.

Your tyre place sounds like they only know cars.

I totally agree with you, it's annoying that people are so incompetent.

 

[john5858]

I’d do 22psi front, 16psi rear.

Your tyre place sounds like they only know cars.

I totally agree with you, it's annoying that people are so incompetent.

Edit:Why should the front pressure be more than the rear, I thought the opposite would be beneficial? I really wondered why

 

[feilding]

I totally agree with you, it's annoying that people are so incompetent.

Edit:Why should the front pressure be more than the rear, I thought the opposite would be beneficial? I really wondered why

Bigger the tyre the less pressure you need for a given load, as the tractor is so light you don't need high pressures. Tyres need a bulge in walls to operate properly. And adjust according to whatever is attached to tractor.. I think rule of thumb is 3 thead bars on ground with given load. Less than 20 psi is a good start on rears.
I've driven a few makes of tractors, Case,Same, MF, NH, JD, and my own Deutz. Tyre pressures can make a tractor very bad to drive. The only make I couldn't get right was JD by changing tyre pressures, never found out why ???

 

[john5858]

Bigger the tyre the less pressure you need for a given load, as the tractor is so light you don't need high pressures. Tyres need a bulge in walls to operate properly. And adjust according to whatever is attached to tractor.. I think rule of thumb is 3 thead bars on ground with given load. Less than 20 psi is a good start on rears.
I've driven a few makes of tractors, Case,Same, MF, NH, JD, and my own Deutz. Tyre pressures can make a tractor very bad to drive. The only make I couldn't get right was JD by changing tyre pressures, never found out why ???

They say it shouldn't be less than 23psi when driving on the road, but I'm looking for a pressure that I can use both on the road and in the field, I can't be bothered with constantly adjusting it (I know it has to be adjusted according to the situation).

 

[Dry Rot]

Why not write to/phone the tyre manufacturer's technical department stating all the relevant details? The reply might surprise you.

I once asked why they were so helpful, almost over board, and was told it is in their interests that customers should be happy and, anyway, it made for an interesting diversion from an otherwise boring routine. You'd be surprised how helpful people can be if asked nicely.

When I was making videos I was using older equipment that needed regular servicing. So I phoned Sony for advice. I was talked through doing a tape path realignment by one of their senior technicians using an oscilloscope. He made the fatal statement, "Call me any time, I am happy to help!". The poor chap. He lived to regret saying that! (I am now pretty good at doing tape path alignments now, but then they spoilt it by going non linear.).

 

[Pistonbroke]

Download the Agro Tyre Pressure app. It's got info from most manufacturers . Depending on load it's saying about 17 for your fronts, up to 20 for rears

 

[john5858]

Tarımsal Lastik Basıncı uygulamasını indirin. Çoğu üreticiden bilgi var. Yüke bağlı olarak önlerde yaklaşık 17, arkalarda 20'ye kadar yaz

The application was very helpful, thank you

 

[smcapstick]

I totally agree with you, it's annoying that people are so incompetent.

Edit:Why should the front pressure be more than the rear, I thought the opposite would be beneficial? I really wondered why

@feilding got it - smaller tyres need more pressure to hold weight.

A good rule of thumb is this - tractor rear wheels 1 BAR, 4wd front wheels 1.5BAR, 2wd tractor front wheels 2BAR.