Dually Pressure

[RClark]

I went and bought a 2002 3500 so now I have dual rear tires to contend with. The inflation charts from Dodge and Goodyear give the lowest inflation pressure as 35psi. At this pressure the load can be up to 6180 lbs. Since I am running about half that when not towing even 35psimakes for a harsh ride.

What do you run?

Goodyear says it is the tires, 235-85R-16(factory) are not designed for lower pressures.

Anybody tried less? 25 or 30 psi

What happened?

 

[RobG]

I was taught by somebody in-the-know that the best way to set your tire pressures is to take the max load rating on the sidewall of the tire, and the max pressure indicated (usually 80 psi in this case), and go with a percentage based on the weight you'll carry.



I know that the back of my truck weighs about 3200# empty, and when I carry my camper, I have 7400# in it. Therefore, I set my rear tire pressures at 55 psi (but my tires go to 95 psi because they're F's, 225/70-19. 5).



Let's say for a moment that the rear tires are rated at 3000 lbs. each in dual format. So 3000 x 4 = 12000 lbs. That's with 80 psi in the tires.



Drop the pressures to 40 psi and you're good for half that, or 6000 lbs total. Drop it in half again (20 psi and 3000 lbs). Me, I wouldn't go that low in tire pressure... I think I'd stay at 35 or higher.



Duallies do not ride that well no matter what you do. About all you can do is replace the entire rear suspension wtih an air ride setup (about $2000), which I may end up doing.



Rob

 

[pwknapp]

Never tried less than about 70 rear and 60 front. Any less than that in the rear and I'd be wondering how much rubbing is going on back there.



My . 02

 

[Steve G]

I run 50 lbs in mine with 300 lbs of sand in back with Ranch 9000s and the ride is pretty good. I agree duallys do not have a good ride. Try the shocks or put some weight in bed and that should help.



Steve

 

[jqram35]

After quite a bit of experimenting and monitoring tire wear, I have found that 60-65 in the front and 40-45 in the back unloaded yields the best tire wear, ride is not really a big factor. I think my dually 4x4 rides pretty good for what it is!

 

[dan_gilson]

I run with 58psi front and 40psi rear. I am lightly loaded. I got to these values by checking the wear every tire rotation which is every oil change for me. If I need to carry something I add pressure starting on the rear first.



I must be doing something right, I have ~62K miles on the original set of tires and I am still . 1" above the wear bars. I will probably get another couple of 1000's miles from them.



"checking the wear" means: I am looking for even wear across the entire tire face. If I have more wear in the center I remove pressure. If I have more wear on the sholders I add pressure.



You could probably try less than 35psi. Things to check for: Are the tires rubbing between the wheels? If yes then add more pressure. Are they warmer to the touch than the fronts? If yes then add more pressure. The reasoning for this is you are carrying more weight on the front axle. If the rears are hoter you are over flexing them and should add more pressure to keep them from blowing out.



Then opinions are my own, use at you own risk and your milage may vary. Best of luck.

 

[dan_gilson]

Oh, I forgot...



More weight will smooth things out. You will need a lot of it. I normally carry ~500# of gear in the back. It does not even phase it. You will probably need a ton plus to get things to settle down and ride more smoothly.

 

[Jack in Alaska]

60 psi in the fronts and 50 psi in the rears, loaded or unloaded.

My rear load is a 2500 pin weight from my 5th. whl.

Wear is normal at those pressures. 66k on 1st set.

 

[Turbo Thom]

JClark>

I'm the same as Jack in Alaska. All the time, 60 in the front and 50 in the rear. Now if you have the helper springs, they are rougher riding. I changed to the Roadmaster setup , with good shocks and the ride is good. Now we do have good roads here in Georgia, but riding through Mississippi and La. nothing rides well. I'm thinking of going with the Kelderman air ride, mainly for the fifth wheel. I can't think of pulling my RV over those roads with glass inside. Paper plates and plastic cups? No.



One thing I did in the rear was go to 55 lbs with a 2600 lb pin weight and 235 tires.



. . Preston. .

 

[Pit Bull]

55 front. 40 rears (unloaded). Seems like everyone is doing about the same thing based on the weight in the truck. I noticed the 55 front for mine makes it track better, and it is wearing evenly.