rear end sway

[Karl23]

Have a 05 dodge 2500 couple weeks ago put new tires on about three days later going around a long curve the rear end felt like it was rolling to far to the right so ive changed the front sway bar bolts and ive checked everything put new bushings in the control arm any ideas i was thinking of changing shocks next

 

[AH64ID]

How many miles on the new tires? How much air pressure?

Some tires are squirmy the first couple hundred miles.

 

[Karl23]

i put about 500 miles on them and they said to run 70psi so that's what i put them at

 

[AH64ID]

Set the pressure for your load, not just a blind number.

They shouldn't squirm after that many miles, but if you are empty and at 70 psi in the rear they won't ever really get warm enough to "break-in". If you are empty I would drop the pressure to the light load numbers on the door.

 

[Karl23]

well my tires say 80 psi and on the door it says front to be 60 and back says to be 45 psi without a load whats your thoughts on that my first thought was that was a big gap there the tera grappler 2 10 ply

 

[AH64ID]

The gap is there because there is a direct correlation to weight carried and air pressure. The tires are rated for, guessing, 3195lbs @ 80 psi. That means at 40 psi they can hold roughly 1600 lbs, and at 45 that works out to 360 0lbs on the rear axle which is plenty of air for an empty truck.

Too much pressure for the weight only decreases ride, increases wear, increases susceptibility to road hazards, and decreases traction.

One my LRE 3195@80 psi tires I run 60/45 empty and 70/80 loaded for towing. On my LRG 4540@110psi tires I run 70/70 empty and 80/95 loaded, 70 is the lowest I can run them for the bead per Toyo.

 

[Karl23]

well im going to lower them down to that for a few hundred miles and put shocks on to

 

[Prairie Dog]

Go with Bilstein shocks, they're the best I've tried.

 

[seafish]

Yup, I used to run that size unloaded at 48 psi front and back just to get even tire wear on them.

 

[MMeier]

Tires are not ride control devices, air them to max on the sidewall and be done ! How many miles on the rig ?

 

[seafish]

Tires are not ride control devices, air them to max on the sidewall and be done ! How many miles on the rig ?

You are right, but they are LOAD control devices and tire manufactureres provide psi load charts for a reason.

 

[Hoefler]

On all my dually's, I have run 80 in the front and 45 in the rear for light/no load conditions. When loaded, 80 all around. I have done this on 4 Ram dually's over 10 years, improved tire wear, traction, and ride comfort.

 

[AH64ID]

Tires are not ride control devices, air them to max on the sidewall and be done ! How many miles on the rig ?

There isn't a single tire manufacturer that would agree with max pressure and be done. It's nothing more than a lazy way to control tire pressure, the only benefit is you don't have to adjust.

Load Inflation tables exist for a reason.

 

[NIsaacs]

There isn't a single tire manufacturer that would agree with max pressure and be done. It's nothing more than a lazy way to control tire pressure, the only benefit is you don't have to adjust.

Load Inflation tables exist for a reason.

I think this can depend on what/how you use your truck. If you are hauling one way and empty on the return (dedicated hauling) it is not convenient to mess with your air pressure. I never know when or where I am going to be hauling or if air is available. I run full air all the time. If all you haul is an RV, 2 or 3 times a year, then air up and down is fine.

Nick

 

[lpennock]

I think this can depend on what/how you use your truck. If you are hauling one way and empty on the return (dedicated hauling) it is not convenient to mess with your air pressure. I never know when or where I am going to be hauling or if air is available. I run full air all the time. If all you haul is an RV, 2 or 3 times a year, then air up and down is fine.

Nick

In that case you use the load table to set the pressures correct for your loaded conditions. Maybe even add 10psi for temperature variations. I would be willing to bet you will find 80psi is higher than you need on all the tires.

 

[cerberusiam]

Given the suspension is good the only difference you should see in tire pressure differences is ride and tire wear.

An E rated tire with stiff enough sidewalls will not change handling from 50 psi to 80 psi on the rear, the front is another story. Depending on the tire, less than 70 psi puts a wallow into the steering at times. The fronts should be aired to acocmodate at least 3/4 of max load all the time or they just don't feel right due to the weight of the engine.

Using the lighter weight rated tires can introduce sway and handling problems UNLESS they are all close to max inflation. The sidewalls on a lot of E rated tires are simply not enough to control the roll from weight of the truck without more air pressure. Inflation tables simply do not take into account the actual vehicle characteristics, not a one size fits all. That and most of these tires are built for Toyotas and 1/2 ton GM's as the target, do not work well on a heavy diesel truck.

 

[AH64ID]

I think this can depend on what/how you use your truck. If you are hauling one way and empty on the return (dedicated hauling) it is not convenient to mess with your air pressure. I never know when or where I am going to be hauling or if air is available. I run full air all the time. If all you haul is an RV, 2 or 3 times a year, then air up and down is fine.

Nick

That may be your technique, but that doesn't mean it's suggested by the tire manufacturer.

Given the suspension is good the only difference you should see in tire pressure differences is ride and tire wear.

An E rated tire with stiff enough sidewalls will not change handling from 50 psi to 80 psi on the rear, the front is another story. Depending on the tire, less than 70 psi puts a wallow into the steering at times. The fronts should be aired to acocmodate at least 3/4 of max load all the time or they just don't feel right due to the weight of the engine.

Using the lighter weight rated tires can introduce sway and handling problems UNLESS they are all close to max inflation. The sidewalls on a lot of E rated tires are simply not enough to control the roll from weight of the truck without more air pressure. Inflation tables simply do not take into account the actual vehicle characteristics, not a one size fits all. That and most of these tires are built for Toyotas and 1/2 ton GM's as the target, do not work well on a heavy diesel truck.

But if the tires are new and have been over-inflated they won't heat cycle and break in as quickly, which can create a squishy feeling.

Weight is weight, 1/2 ton or 1 ton with enough air to support 5K lbs the tires should be fine. A little extra air on a hot day or lots of high speed travel is a given.

 

[NIsaacs]

I would be willing to bet you will find 80psi is higher than you need on all the tires.

Maybe, but like I said I never know what I am going to haul. I would rather have too much than not enough. Fuel mileage/tire temp is important to me, I drive fast and heavy, on and off highway and don't always have air handy. Here are a couple pictures of very different loads, they always vary.

Nick

 

[lpennock]

Maybe, but like I said I never know what I am going to haul. I would rather have too much than not enough. Fuel mileage/tire temp is important to me, I drive fast and heavy, on and off highway and don't always have air handy. Here are a couple pictures of very different loads, they always vary.

Nick

I agree with you on the rear. My SRW needs the full 80psi on the rear with my Cabover camper (70pai actually and I add 10 psi for temperature changes). On the front I see less than 10psi difference loaded to unloaded and both numbers are in the 50s. With a dually 80 psi rear is way overkill (assuming you are staying anywhere close to axle GWR).

 

[Karl23]

i do haul a camper or trailer every weekend during summer i was just putting new shoe's on it and getting it ready for summer i do drive it most everyday i just cant figure how it can have so much sway from the rear i went to pass a car on the way home and the *** end made me feel like i was going to roll it when i went back to my own lane i had this thing on the lift about every day looking for something wrong im not finding anything i had everybody i know look at it and there opinions today i will change the shocks