3500 continuous, rhythmic bounce on concrete highway

[AH64ID]

I've driven those Colorado highways many time and have had some luck in upgrading my truck. 1st) I removed my un-leveling kit that made a huge difference in reducing bounce, don't add a leveling kit, it really increases the bounce 2) lowered my f/r tire pressure to 65 when unloaded. 3) have a camper shell adding weight to the rear, 4) added sulastic shackles to my rear leafs (huge difference), 5) replaced factory dampers with bilstien. 6) switched tires. Now the truck rides better unloaded than loaded. rides great on concrete freeways no problems in the houston area which are all concrete practically and Colorado. In fact it rides so much better, that I find myself driving at 80+ on concrete roads as they barely disturb the truck. Which is a 3500 megacab as well. The biggest changes were adding the sulastic shackles, ditching the leveling kit, and lowering air pressure in that order. The shocks made the least difference. I'd suspect reducing unsprung weight would help, more advanced shocks that are frequency selective damping instead of singe valved, getting rid of solid axles....

That's still quite a bit of air pressure for unloaded, as you can run 6,170lbs on each axle (OEM sizes) at 65 psi.

 

[thecastle]

I don't disagree, I'm just saying that 65 was enough reduction for me to ride fine in conjunction with the other mods I've done. Lower won't make it worse!

 

[MarioM]

Is this kinda thing going to get better when towing decent weight? How is this not going to destroy a travel trailer?

Twoing weight does not fixes the issue, it is the same . I tow 10 to 20 thousand lbs regularly the bouncing and jumping does not goes away.

 

[Lord muta]

So I’ve had this problem in my Chevy 1500s and in my power wagon.

Some has to do with suspension stiffness and tire inflation etc. but what it comes down to is wheel base. I’m in Arizona (Phoenix) we have the 303 freeway. It’s got a huge portion that is concrete. I had 2 different chevys. One with the cab and a half so not 4 full doors.. it had no issues at all. My next Chevy had the 4 full doors just a few inches longer than my other Chevy. Better suspension and tires but I had the harmonic bouncing going on. Speed helps change where in the suspension rebound the sections of the road hit the truck. Faster was better. 80 rides nearly smooth 85 rides like my rebel did. Smooth as butter. Slow down and my power wagon bounces along like popcorn.

Don’t let it get you down. It’s just the way it is with a longer wheelbase or an HD truck

 

[AA0AC]

Hi Everyone-

I just traded up from my 1500 to a new 3500 6.4L SRW. On sections of highway or streets that are concrete, it starts this rhythmic, fast and continuous bouncing up and down. Feels like I’m going to bite my tongue off. The concrete itself looks smooth, but for some reason the truck gets into this bouncing rhythm immediately.

However, on asphalt highways and streets it rides great. A bit rough when hitting random bumps, but is what I expected with such a stiff suspension, and how it rode when test driving. After reading the forums I dropped the tire pressure down to 50 front, 45 rear, but it still didn’t seem to do much for the concrete driving.

What is going on here? Would adding steel bumpers front and rear help by adding weight? Billstein shocks up front? Air suspension?

Any help is appreciated

I am new to this forum, but I have had the same problem with my 2017 3500 SRW Crew Cab 8ft Box. I have had this truck since new, and the bounce has gotten worse over the last couple of years. It is always on concrete road surfaces but not on bridges or over passes. I have tried lowering tire pressure, adding up to 800 pounds in the box, changing tires, and none of it stops the bounce. When I add my 9'2" boss v-plow on the front of the truck it gets worst, my suspicion is with the weight transfer to the front axle it unloads the rear which increases the severity of the cab bounce.
I have reached out to a couple shock manufacturers to see if they have a recommendation. The truck is supposed to have a stiff suspension and ride, that is part of owning a 1 ton truck, to handle heavy loads.
Have you had any success on your end as of yet?

 

[Lord muta]

Hi Everyone-

I just traded up from my 1500 to a new 3500 6.4L SRW. On sections of highway or streets that are concrete, it starts this rhythmic, fast and continuous bouncing up and down. Feels like I’m going to bite my tongue off. The concrete itself looks smooth, but for some reason the truck gets into this bouncing rhythm immediately.

However, on asphalt highways and streets it rides great. A bit rough when hitting random bumps, but is what I expected with such a stiff suspension, and how it rode when test driving. After reading the forums I dropped the tire pressure down to 50 front, 45 rear, but it still didn’t seem to do much for the concrete driving.

What is going on here? Would adding steel bumpers front and rear help by adding weight? Billstein shocks up front? Air suspension?

Any help is appreciated

This is in part the suspension and the wheel base. I had a 1500 that bounced just like my 2500, My Rebel didn't bounce at all. Smooth as a baby's butt. My Power Wagon gives me an unintended 'message' while driving on some highways made of concrete. It is what it is. As you stated, a load will help reduce this but how much load is truck specific. Welcome to HD life my friend.