R4 Tire PSI

[WV John Deere]

How much air pressure should be in a set of R4's? Mine are on a 3520, loaded w/ methanol. The sidewall has a maximum rating of 34 psi. How low of pressure can I go? This thing rides like an oak post! They don't bag at all.

 

[RoyJackson]

As far as "ride", I don't know what you're expecting...these are tractors and have no suspension. Just realize what you're operating. We ain't discussing a Cadillac here...

Before adjusting the tire pressure, does your machine have a suspension seat? If so, have you adjusted the seat per your tractor's manual? Read under "Adjusting Seat". You might even want to go for the "Deluxe Seat" if you don't have one.

As far as pressure, what are you running now? Is it 34 PSI (use an air/liquid gage and the valve stems must be at the 12 O'Clock position when you check the pressure)?
If it is 34 PSI, drop it to about 25. BTW, you'll want the tractor jacked up when you adjust the tire pressure. Jack on a solid surface and position your floor jack under the drawbar bracket. Jack it just enough to clear the floor (1/4 inch is plenty). I suggest you go no lower then 25 PSI. Even at that pressure, your tires could break from the bead at a significant side load (traveling across a slope). Read your manual and determine if there is a minimum pressure before you reduce the pressure

If it's still too harsh after adjusting the seat and lowering the tire pressure...well, you'll just have to "man up" and realize that R-4's may not be the tire for you.

 

[WV John Deere]

Thanks Roy,

I wasn't expecting a terrific ride from a tractor with such a small wheel base. I've got the seat adjusted for my weight.

I've narrowed down the possibilities of improving the ride to the tire pressure. With a 5X5 dry bale on the loader and one on the rear, the tires don't bag at all.

While I've never used this small of tractor for this kind of work, my experience with other larger tractors with loaded tires is that the rear tires usually have a slight bagging to them, even without any "load" on them. I have none.

Could also be the difference between the R4 vs. an agriculture tire. Just trying to look at any and all possibilites and right now I'm trying to out rule the tire pressure.

Thanks buddy:thumbsup:

 

[RoyJackson]

Could also be the difference between the R4 vs. an agriculture tire. Just trying to look at any and all possibilites and right now I'm trying to out rule the tire pressure.

Thanks buddy:thumbsup:

My pleasure...just one of the great benefits of being a member of TBN!!

I'm no expert on tires and have no experience with R-1's, but I'm pretty sure those R-4's have a significantly thicker sidewalls (less flexing). Tough tires for rough use, but definitely not built for comfort.

 

[nmu98]

I never had loaded tires on a compact, so do you run more PSI in them since they are laoded?


I run 14psi in my R4's on the back of my 3720 (not loaded). Any more than that and the tractor gets bouncy and rough.

 

[RoyJackson]

I never had loaded tires on a compact, so do you run more PSI in them since they are laoded?


I run 14psi in my R4's on the back of my 3720 (not loaded). Any more than that and the tractor gets bouncy and rough.

No...same pressure as if they were not filled.

14 PSI seems a bit low...just be cautious you don't roll a tire off the rim.
There's nothing wrong with tailoring the tire pressure for the task at hand. I kept my front tires at about 20 PSI, but if I had a loader task, I upped the pressure by 8-10 PSI. Rear pressure (with R-4's) was always kept about 20 PSI.

 

[nmu98]

They have been that way for almost 3 years Roy with zero issues.

I know they are different tires, but I run my jeep tires down to 8psi when offroading and I have never popped a bead. I think you would be hard pressed to "roll" a tire with 14psi in it These are thick walled tires without much side flex.

 

[RoyJackson]

They have been that way for almost 3 years Roy with zero issues.

I know they are different tires, but I run my jeep tires down to 8psi when offroading and I have never popped a bead. I think you would be hard pressed to "roll" a tire with 14psi in it These are thick walled tires without much side flex.

Good info!
Wow! 8 PSI sounds mighty low!
20 PSI always seemed like a good compromise to me, considering the maximum pressure on the tire was 30 PSI or a bit more. That's definitely not a hard and fast rule...it's just what I do.
Maybe my butt has enough callouses so rough riding doesn't bother me!

BTW, I'm basing my comments (especially about the front tires when using the loader) after almost rolling a tire off the front of my old 670. Those sidewalls were darn near flat and rolled considerably when I made a turn. In that case, I dropped the load (which was an old boiler housing of some sort), aired up those fronts and finished the job.

 

[mustangsallysdad]

They have been that way for almost 3 years Roy with zero issues.

I know they are different tires, but I run my jeep tires down to 8psi when offroading and I have never popped a bead. I think you would be hard pressed to "roll" a tire with 14psi in it These are thick walled tires without much side flex.

They are thick walled, but the aspect ratio (sidewall height to tread width) is very different between an automobile tire and the front tire on a compact tractor...it really doesn't take much to roll them little suckers off the bead. Unfortunately, I speak from experience.

 

[DanD78]

I blow the front tires to the high pressure from the manual and the rear low enough so the tread will leave a full width print when you run a wet tire across dry concrete. Mine are loaded with rim guard front and back. You see a lot of people with over inflated tires and only touching the ground in the center of the tread.

Dan