Tires Tire Pressures, How low can you go ?

[bigreddmax]

I searched the forum but couldn't find anything on this topic...I have a JD 2305 and for mowing only, I would like to lower the tire pressures for a better ride. How low can I run them? All the manual gives are the maximums:

Front Tire Inflation Pressures (Maximum)
18x8.5-10 R4 152 kPa (22 psi)
18x8.5-10 R3 152 kPa (22 psi)

Rear Tire Inflation Pressures (Maximum)
26x12.00-12 R4 138 kPa (20 psi)
26x12.00-12 R3 138 kPa (20 psi)

 

[RalphVa]

Somewhere, folks talked about this and mentioned going as low as about 8 or 10 psi on the REAR tires before they'd tend to rotate on the rims. I'd advise against going lower than 22 psi on the fronts. You can easily push them right off the rims if the pressure is very low.

Ralph

 

[bigreddmax]

I found where the fronts are rated for 829 lb @ 22 psi while the rears are rated at 1780 lb @ 20 psi.

Using a 50/50 front /rear split and 2000 lbs total weight (tractor, mower, driver), I've calculated 13.3 psi for the fronts and 5.6 psi for the rears.

Does this sound right? Is my 50/50 front/rear weight split assumption close ?

 

[pruntyc]

The lowest pressure for the 4100 in their manual calls for 12 LB for the lowest. I know they are a different size but it calls for the 12 lbs front and rear. The maximum on the rear of it calls for 41 lbs and the front 22. So I think you would be fine with 12 in both of yours, not sure I would want to go any lower.

 

[pat32rf]

When my 4300 arrived I took off up The Hill to try it out. Rode rougher than H. Bounced on the seat to the point that the seat switch would cut out. This was in mid range, on a rough trail. As soon as the dealers truck left I checked the tire pres.-35psi in the rear. I find that when they are loaded 10psi works for me as I am on rough rock, sticks and logs a good part of the time.The fronts are about 20 because of the loader.

 

[RalphVa]

I repeat; I would NOT lower the pressure in the fronts. I had one of mine go off the rim already. I make sure they're at 22 psi now. They just don't have the sidewall strength without that pressure there. Your calcs won't take this into account.

Ralph

 

[RoyJackson]

"35psi in the rear. I find that when they are loaded 10psi works for me as I am on rough rock, sticks and logs a good part of the time.The fronts are about 20 because of the loader."

35 PSI in the rear tires...sounds like the shipping pressure. That should have been lowered as part of the dealer prep. I keep mine (filled with windshield washer fluid) about 15 PSI.
The fronts are kept at 25 PSI with or without the loader.

 

[Turkflyer]

You guys are right on target. The fronts need to stay in the 20's, and the rears can go down in the teens for psi. The 35psi was definately the "Ship-Away" pressure and should have been reduced by the dealer. I'd use about 12 as a minimum for the rear. The front depends if a loader is used. You'll need more in the fronts than the rears.