Feels mushy while towing

[Mjewell5]

Hello all. I have a 2016 Quad Cab 1500 4x4, 5.7 Hemi and 3.21. gears. The front end is leveled with Bilstein shocks all the way up, and I have air bags in the rear. I tow an 8000 lb (approx) travel trailer with an Equalizer weight distributing hitch. The hitch setup seems to be spot on: truck and trailer are both level, and the truck is about 1/2" lower with the trailer on. I just put 10 PR tires on as well - 275/60-20. My problem is that when I tow, it feels like the truck is coming loose in three different directions! It kind of feels like the axle is loose and the rear of the truck seems to rock back and forth excessively. The best description I can give is that it feels like the tires are filled with mashed potatoes! I don't know where to turn next. I've looked underneath at the track bars thinking the bolts were worn out, but didn't see any obvious problems. I've noticed that it seems to have these problems whether the trailer is on or not, but it's worse with the trailer on. Any ideas where to look and what to look for? Thanks for any help!

 

[csuder99]

Too much of everything . Getting the truck level is last millennium when trucks had leaf springs in the rear. Typical "Front Axle Load Restoration" (FALR) numbers are around 50% (that's what SAEJ2807 specifies IIRC). The rear axle is likely not able to follow the road well.
You have to experiment a bit (assuming the tongue weight is about 12-15% otherwise fix that first). Start with minimum pressure in the airbags and set the WDH so that you have a little more sag in the rear (it's gonna look bad because the truck is leveled). You can approximate the 50% starting point by measuring the truck height at the front wheel, hook up the trailer without spring bars, measure again and then split the different with the bar tension. See if it feels better, and then play with airbag pressure next.

 

[clifford15]

What air pressure are you running?
My ‘96 was real “mushy” feeling when I put a set of P tires on it. The worn LT tire were way better. You mention 10 ply tires which I assume are LT rated?

 

[crash68]

The truck being level doesn't mean much, where you have the weight loaded does. Being your pushing the upper weight of 1500 towing it's a good idea to set up the WDH using actual weight, find a local semi truck CAT scale.
You'll want to weigh the just the truck then the truck and trailer with WDH, you'll want every loaded like your head out camping. Using the axle weights from both weight slips you'll be able to calculate how much tongue weight you have and see how much the WDH needs to be adjusted. It's a good idea to put all the front axle weight back as long as the rear axle weighs more than the front.
As for setting the airbags, I'll usually put enough air in them to take up about half of the amount of rear end sag before setting the WDH.

 

[Daw14]

Might check your rear control arm bushings,if they’re worn it will drive similarly.

 

[2003F350]

The truck being level doesn't mean much, where you have the weight loaded does. Being your pushing the upper weight of 1500 towing it's a good idea to set up the WDH using actual weight, find a local semi truck CAT scale.
You'll want to weigh the just the truck then the truck and trailer with WDH, you'll want every loaded like your head out camping. Using the axle weights from both weight slips you'll be able to calculate how much tongue weight you have and see how much the WDH needs to be adjusted. It's a good idea to put all the front axle weight back as long as the rear axle weighs more than the front.
As for setting the airbags, I'll usually put enough air in them to take up about half of the amount of rear end sag before setting the WDH.

This is by far the best and most accurate way to get it done. It is also helpful to have the trailer level behind the truck, even if your truck is squatting in the rear.

I have never had to make a trip to the scales to set everything up, BUT I also have years of experience setting up a LOT of different trailers. At this point I have enough experience I can eye-ball it, and on the first drive I usually know if it is right or not, and what changes to make.

 

[VernDiesel]

Crash nailed it. Get your unloaded slip. Then get the loaded with trailer slip. Between the steer, drive, & TT axle weights see actual tongue weight you find your problem and what you need to do to find true north.

 

[Daw14]

Might take a look at your track bar bushings,

 

[tron67j]

Echo the statement about Crash's statement. Since your truck has around 1600 lbs payload, take away 600lbs for people, hitch set up, and stuff in the truck, that leaves about 1000lbs for trailer weight on hitch. Your bags are masking the problem visually by not showing true sag; you are probably a good amount over your rear carrying capacity which both pushes down on rear and makes it squirrelly as well as takes a lot of down pressure off your front wheels and diminishes steering and stopping capacity. And if you are loading more weight in back of trailer to try and reduce hitch weight, it increases sway. Get all your weights at scale while loaded with everything you travel with. Think your solution is going to be reduce gear and supplies in trailer and truck. Good luck.

 

[Firebird]

Lots of excellent info on here! But to me, it sure seems like a situation of too much trailer and not enough truck?

 

[dhay13]

Yep, you are likely over your legal payload and pushing the limits of a 1500. Your payload is probably closer to 1300-1400 and that 8000lb camper alone is probably about 1000lbs of tongue weight. Air bags are a feel good thing, they don't increase and limits.

But as was said, get your weights so you know where you are at.

 

[mtofell]

Too much trailer for that truck.

 

[GsRAM]

Perhaps too much trailer, but without actual, loaded, ready to camp weights it's just a guess. As crash 68 so perfectly outlined above.

You can tow heavy with a half ton, I've done it many years, but when you push the upper limits, everything has to be spot on with set up or you'll have your hands full.

If that was mine, I'd ditch that level and go back to stock. Lifted trucks are no good for heavy work. The factory rake is there for a reason.

I think your either way heavier than you think you are, or the wdh is not adjusted property and you don't have the steer axle weight returned to its unhitched weight.

Possibly some worn suspension components. One things for sure. When you load heavy and work something hard, the weak points show themselves pretty quick.

Good luck

 

[Mjewell5]

Thanks for all your help. I think I've decided to just go to a bigger, more appropriate truck. Looking now at 3500's, because I see a fifth wheel in our future. Again, thank you all for your help!

 

[Firebird]

Thanks for all your help. I think I've decided to just go to a bigger, more appropriate truck. Looking now at 3500's, because I see a fifth wheel in our future. Again, thank you all for your help!

Good decision!

 

[JayLeonard]

I also had a 1500 cc and was overloaded with my 7500 lb TT.
just drove tis baby home wednesday night.2500 Bighorn cc with the Cummins

 

[Bldrinker]

I had a 1500 with a 7,000-7500lb trailer.

you are experiencing the limits of that truck period.

 

[RLJ10X]

He's maxed out with those 3.21s. 3.92s, he had a little wiggle room. My Standard Reply: Lower Rear End Gears!

 

[Bldrinker]

View attachment 236567 He's maxed out with those 3.21s. 3.92s, he had a little wiggle room. My Standard Reply: Lower Rear End Gears!

Can you please explain how gears will fix the complaint of the rear end feeling “loose”

 

[GsRAM]

I also had a 1500 cc and was overloaded with my 7500 lb TT.
just drove tis baby home wednesday night.2500 Bighorn cc with the CumminsView attachment 236460

Very nice! Congrats! Good decision Sir.