Better ride when not towing?

[Gator398]

Is it possible, to make a dually truck not shake like an earthquake on expansion joint roads when the trailer is off???!!

I have read about the kelderman 4 link or whatever, is that our only option?

[Grit_dog]

Seriously, you have enough air in them tires to hold 10klbs.
Let almost half the air out of the back tires and go for a ride. See what you think.
Don’t over complicate this. Air is basically free and easy to change.

[Gator398]

I have a 4wd, last weighed trailer is 5840# and 1100 of that is tongue. This was before current setup though with bicycles on rear hitch rack, so that may have increased weight but decrease tongue a bit. I will cat scale weigh on return trip, last time I weighed I put tongue Jack on drive axle pad, unhooked and put truck on steer pad, leveled trailer. Next time I will measure exactly where hitch is hooked up before unhooking and return to that height to get most accurate tongue weight. Does anyone do this differently?

[wopachop]

Grit dog wrote:

Me Again wrote:

wopachop wrote:
Some people add sandbags during winter to get some weight over the rear tires to keep from spinning. Could do that during summer temps just to improve ride.

Loading air into and out of rear tires is easier that sand bags!!!!!

And both methods would work separate of each other or in conjunction as the 2 methods do 2 completely different things to the vehicle.
But in the context of this thread, it would take around 20 sandbags, lol, to make a noticeable effect on a duallys suspension. And a pain in the ____to deal with.

Or tools or toys. Ive never actually owned a car. Just trucks and a k5 blazer for a bit. Not a fan of how they feel with the bed unloaded. Couldnt think the last time i drove my truck with zero weight in the bed. I got toolboxes back there. If i didnt have tools then i would use sandbags or something. But i hear ya about the amount of weight needed for a 1 ton. My girlfriend drives a lifted f350 and that thing is stiff on the rare occation we drive it without the trailer hooked up. I remember taking it 4 hours to John Woods to do the tranny. That was a bouncey stiff ride.

[Grit_dog]

FWIW some states have recognized this effect and gone to random Control jt spacing on concrete roadways. NM changed their spec 20+ years ago from standard spacing to random or more accurately a “random pattern of different spacing.” Some still don’t understand this (WA).

[Cummins12V98]

Gator have you weighed your rig LOADED???

Is your DRW RAM 2 or 4wd?

The 30-35psi rear is for when you are NOT towing.

[Grit_dog]

PS, your theory about tire heat is valid “if” you’re running too low of pressure, but you’re incorrectly assuming what the right pressure is, I believe.

[Grit_dog]

Gator398 wrote:
Here's an update: front tires are at 65, rear duals are at 60, just took the TT on our first long haul 1200 mi total. I will weigh tomorrow when I fuel, the ride was awful most of the time until I passed OK state line, so this is a road problem. Only on Oklahoma highways so far have we driven in these concrete "expansion joint" highways I believe they are called, where every section is raised a bit and results in a constant "tha-thunk tha-thunk". So far the costly toll turnpike to Hugo was the worst and nothing but smooth roads (occasional rough patches as normal) since, we just crossed into Alabama tonight.

Edit: Also this is not a daily driver so I would appreciate advice on towing conditions only. 30psi in rear on stock size tires when towing, with road temps rising now, is asking for a blowout at 75mph. All valid points about lowering pressure to improve ride but don't forget while towing, this raises heat fast in summer causing tire failure if not pulling over frequently enough to let them cool.

The biggest issue with what you described is not tire pressure but concrete roadways with the control joints cut symmetrical. Concrete does “swell” eventually at exposed joints. More so on cut or cracked joints as that surface is more permeable.
If the joints are spaced evenly they can/do initiate a harmonic pattern in some vehicles.
Stiff suspension ( and tires but you’d have to run them pretty soft to overcome at highway speeds), wheelbase length and weight transfer off the front axle (like towing a trailer or loaded pickup bed) exaggerate this effect.
However, back to tire pressure, no one is suggesting 30 psi in your duals while towing, or are they? Load pressure chart for 235-80-17s gives you 6900lbs of capacity for 4 tires at 35 psi. What does your rear axle weigh? You pull a TT so not very heavy on the truck axle comparatively. If you had 4 large passengers, 1000lbs of gear in the bed and 1500lbs tongue weight, you still wouldn’t break out of the available load capacity of your rear tires at 35psi.
At a very small theoretical penalty in fuel mileage due to rolling friction, running the “proper” pressure for the load will always yield the best ride, general handling characteristics, traction and minimize tire wear. And you’re running 10klbs worth of air for presumably waaay less load than that. But icbw on you axle loads.

[Grit_dog]

Me Again wrote:

wopachop wrote:
Some people add sandbags during winter to get some weight over the rear tires to keep from spinning. Could do that during summer temps just to improve ride.

Loading air into and out of rear tires is easier that sand bags!!!!!

And both methods would work separate of each other or in conjunction as the 2 methods do 2 completely different things to the vehicle.
But in the context of this thread, it would take around 20 sandbags, lol, to make a noticeable effect on a duallys suspension. And a pain in the ____to deal with.

[Gator398]

Here's an update: front tires are at 65, rear duals are at 60, just took the TT on our first long haul 1200 mi total. I will weigh tomorrow when I fuel, the ride was awful most of the time until I passed OK state line, so this is a road problem. Only on Oklahoma highways so far have we driven in these concrete "expansion joint" highways I believe they are called, where every section is raised a bit and results in a constant "tha-thunk tha-thunk". So far the costly toll turnpike to Hugo was the worst and nothing but smooth roads (occasional rough patches as normal) since, we just crossed into Alabama tonight.

Edit: Also this is not a daily driver so I would appreciate advice on towing conditions only. 30psi in rear on stock size tires when towing, with road temps rising now, is asking for a blowout at 75mph. All valid points about lowering pressure to improve ride but don't forget while towing, this raises heat fast in summer causing tire failure if not pulling over frequently enough to let them cool.

[Me_Again]

wopachop wrote:
Some people add sandbags during winter to get some weight over the rear tires to keep from spinning. Could do that during summer temps just to improve ride.

Loading air into and out of rear tires is easier that sand bags!!!!!

[wopachop]

Some people add sandbags during winter to get some weight over the rear tires to keep from spinning. Could do that during summer temps just to improve ride.

[noteven]

The Bridgestone R250's x 6 on my toyhauler are MAX 99mph rated.

Now everything tires in RV Land has to be MAX... but as I've said before the old Dodge has quite a time getting that trailer up to MAX rated speed...

[Cummins12V98]

At 43k on my Michelins that have never been rotated with 43k they are just under 8/32" with lots of life left front and back. Also along with even tread wear.

[Cummins12V98]

Me Again wrote:

Grit dog wrote:
Well, I’m a man of my word! I got your $20 the next time I’m passing thru Oklahoma!
Or hit me up if you’re in Seattle. :C

But in the mean time, the right pressure is based on weight and you appear to be categorizing all 4 wheels the same.
Go outside, set your fronts at 50-55lbs (assuming stock ish size tires) and the rears to 35psi and take a quick test drive.
65 is acceptable but stiff up front and still rock hard on the back of an empty pickup.

You would want to air up a bit in the rear when hauling the TT but 65psi will handle the full tongue weight of a wavier trailer than yours AND a bed full of stuff.

50-55(2270 lbs - 2370 lbs) in the front of a dually is way underinflated if it is a diesel truck assuming 235/80R17Es. Front axle of my 2015 3500 SRW is 5120. Dually will be at that or more as most set nose down. The skinny tires on the front axle need almost the full side wall inflation of 80 PSI to handle the static weight of the front axle. I am surprised the Ron was not all over this???

Now for the rears, that tire at 35 PSI dual is rated at 1570 or 6280 for an empty axle that weighs in at 3-4,000. So at 35 PSI one could still throw a ton of stuff in the bed and not be under inflated. Chris

I run 80 fronts on my DRW all the time. Even with 6k pin the front weight increases less than 200#.