1st real tow w/ my '17 F350 dually

You don't say what air pressure you are running the rears at, but having the correct amount for your load may help.

Jerry

I'm pretty sure you're feeling the overload leaf engage. When you are unloaded, it'll never touch the spring pads. If you have a really heavy load, it stays engaged and you also don't feel the jolt of it smacking the spring pads. Moderate loads are kinda the sore spot where you have just enough gap the overloads aren't engaged, but they smack the pads over bumps.

2 solutions (if this is what's happening): 1) Remove the overloads. This is a good solution if you'll never be loaded much heavier. 2) Install Stabil-Loads so the overloads are fully engaged.

https://www.torklift.com/rv/stableload

MFL wrote:
You don't say what air pressure you are running the rears at, but having the correct amount for your load may help.

Jerry

\

X2

Most of the duallies only need 65 inflation in the rear for full axle load(Ford RGAWR 9650). Empty, 35-40 will greatly increase the ride quality.

No free lunch here. For years the Ford's have needed air bags because of the soft springs if hauling heavy. Sounds like the soft springs are gone. So correct inflation for the load may be the only way out without messing with the suspension.

Here is the inflation info for LT245/75R17E in DUAL application.

PSI Load rating
35 1610
40 1770
45 1920
50 2040
55 2210
60 2350
65 2535
70 2615
75 2750
80 2910

Sorry if I mislead you, but I do not have air bags. Was just saying that the ultimate set up would be a truck w/ just 2 airbags like semis have.

I want to say that carringb may have hit the nail on the head. Although I haven't weighed this truck/RV combo yet, last year the RV pin was 3700 lbs (same RV, diff truck then). I had the upper and lower Stabil-Loads and ended up removing the uppers and just going w/ the lowers and had very good results. Using both was a BUCKBOARD ride. If I read carringb's post right, should I install the uppers so the aux spring is engaged all the time? Won't that make for a harsh ride unloaded? If I do re-install the uppers, not sure how well they will work so to speak as I cut them down substantially on last truck so they weren't hitting all the time unloaded. OR on the other hand, they may "take up" enough of the gap to lesson the "bang" upon rebound?

In regards the Ford having too soft of springs, I'd agree w/ that on their 250's, but their 350's seem pretty snug.

ACZL wrote:
Sorry if I mislead you, but I do not have air bags. Was just saying that the ultimate set up would be a truck w/ just 2 airbags like semis have.

In regards the Ford having too soft of springs, I'd agree w/ that on their 250's, but their 350's seem pretty snug.

I have a F250 LB CC and it rides very well. Having said that, I was going to buy an F450 next year, but now I think I'll wait for the 2020 model that should have the 10 speed transmission.

Normally I use my truck for my DD, but if the F450 proves to be too rough I may have to buy a little rice rocket of some sort for daily use.

Bill

Yup, take a peek under there when you're hitched up and ready to roll. If the overload springs aren't touching the frame brackets, you're suffering from what I call "overload slap." Happens on mine with just the camper in back. Hitch up the trailer, and it goes away.

We found that towing with our 2015 350 DRW was a much harsher ride than our new 2017. We've never towed this trailer with a SRW so I can't speak to that difference. That being said, filling up the water tank in the trailer even halfway seems to make a big difference in smoothness as well.

Not cheap, but our Trailer Saver BD3 hitch really smooths out the ride. It pretty much isolates the movement of the trailer from the truck. I had air bags on a previous truck and they do help some. I posted on the other post you made about shocks the model numbers of the Rancho's I put on mine. Really pleased with them.

This trip we took was just the DW and myself, fresh tank full (dry camping). Have noticed that the aux springs have made contact w/ the brackets, but never associated the gap as to what could be my problem. Next trip isn't for another week or so, but if my pea size brain recalls right, I don't think there was contact (enough weight) for brackets to sit on springs sitting still. Truck only squats about 2" or so.

Thanks for the replies gang. New world of duallies sure is an eye opener.