Bouncing on Concrete Roads

[dozment]

We just finished our fourth trip with our new trailer. Been camping for years with a smaller trailer, but just moved to a 31'.

I have a situation that I need to figure out when we are on roads that are concrete with expansion joints. It doesn't happen on asphalt paved roads. On the roads with expansion joints every few feet if I'm driving at more than about 50 MPH the tow vehicle starts bouncing.

The trailer doesn't seem to sway. It just goes from a smooth ride on asphalt to bouncing so hard we can't hold a conversation until I get it under control by slowing down.

It feels very dangerous. I had a about 20 miles on it on this trip. Part of the time I was doing 50 and traffic around me was doing 80. That seems dangerous, too.

Tow vehicle is a 2018 Chevy Silverado 1500 with the max trailering package. Tow capacity is supposed to be 11,000 pounds. My trailer weighs 7,300 pounds.

Any suggestions as to how to deal with this? The max trailering package is supposed to have a stiffer suspension. Would stiffening the suspension even more help with something like this?

Thanks for any advice.
Dan


I just realized I posted this in Toy Haulers. My trailer isn't a toy hauler. Just made a mistake, and I don't know how to move the post!

[hvac]

deltabravo wrote:

dozment wrote:
So, is my pin weight the difference in those two?

This would be Tongue Weight.

PIN weight is a term used for 5th wheel trailers, not bumper pull trailers.

The person that mentioned the term originally has now confused the issue.

I see it now!cool. I might get one. Really tough to justify on current set up. Air suspension on the ram on all 4 corners really give a cushioned ride. But, it would be best to isolate the coach.

[deltabravo]

dozment wrote:
So, is my pin weight the difference in those two?

This would be Tongue Weight.

PIN weight is a term used for 5th wheel trailers, not bumper pull trailers.

The person that mentioned the term originally has now confused the issue.

[campigloo]

hvac wrote:

campigloo wrote:

hvac wrote:
I don't think the gen y hitch would work with the Andersen system. Appears you would not have any sway control.

It should work just fine with Anderson. His bounce is up and down motion. Sway is side to side motion. One has nothing to do with the other.
To op, you could also try adding StableLoads to your truck. It essentially adds an additional leaf to your rear suspension. It worked nicely on mine.

Ok, but sway with Andersen is in the ball and friction material inside the hitch. Wouldn't sway be lost?

It shouldn’t have any affect because the Gen y mounts between the receiver tube and the hitch head and has no side to side movement. I’m not good at attaching links but if you go to their web site it’ll quickly make way more sense than I can explain.

[hvac]

campigloo wrote:

hvac wrote:
I don't think the gen y hitch would work with the Andersen system. Appears you would not have any sway control.

It should work just fine with Anderson. His bounce is up and down motion. Sway is side to side motion. One has nothing to do with the other.
To op, you could also try adding StableLoads to your truck. It essentially adds an additional leaf to your rear suspension. It worked nicely on mine.

Ok, but sway with Andersen is in the ball and friction material inside the hitch. Wouldn't sway be lost?

[dozment]

Charles, the road that's giving me trouble is 575/515 from around Canton to Elijay. It clears up near Elijay and comes back between Blue Ridge and Blairsville.

My alternate route is 411 to Fairmount and then 53 and 136 to Talking Rock. Not a bad drive at all. I just need to find a way around more of it.

[CharlesinGA]

I encountered this on one section of highway in my Sprinter chassis motor home. On a fairly newly poured section of Nebraska highway 2, near Nebraska City. Basically the last 10 miles before you left the state. It is four lane, divided, and looks GREAT. Eastbound on the outside lane, up hill sections, the motor home would start crow hopping badly. There was no traffic so I would switch to the inside lane where it was barely noticeable.

My thinking is that the concrete on the upslopes slumped enough during its pour to create an invisible washboard that coincided with the 158 inch wheelbase of the motor home. Probably all that was needed to fix it is grinding that lane with a pavement/concrete grinder. Grinding is rather common practice now on newly poured sections of interstate here in Georgia, as this eliminates the small ripples, raised edges between slabs, etc that occur during the pour.

Charles

[campigloo]

hvac wrote:
I don't think the gen y hitch would work with the Andersen system. Appears you would not have any sway control.

It should work just fine with Anderson. His bounce is up and down motion. Sway is side to side motion. One has nothing to do with the other.
To op, you could also try adding StableLoads to your truck. It essentially adds an additional leaf to your rear suspension. It worked nicely on mine.

[myredracer]

dozment wrote:
So, the front is sitting about the same height, and the back drops about 1 1/2". Does that sound reasonable?

We're taking another trip in a couple of weeks, and this one will take us by a place with scales. So, I'll get loaded measurements of the weight while we're out.

Sag of 1-1/2" is normal and not an issue. You want the TT to sit level to slightly nose down when the WDH is hooked up.

It's always a good idea to go to a scale and get all the weights. If you can at the particular scale, it can also be good to get side-side weights on the TT because they can be heavier on one side due to a slide(s) and what's in it.

[dozment]

Thanks again for all of the good info. I think my approach for now as I learn more about this is going to be to control it with speed and routing.

I'm driving a brand new TV, and it's a new TT. The TV handles the TT well except for these stretches of road. I think I will just avoid most of it and slow down for the unavoidable.

I checked out my Equalizer hitch yesterday. Without listing all of the measurements the differences for the front of the TV seemed minimal to me (the uneducated). When I dropped the trailer on with no WD the front fender went up by 1/2". Adding the WD bars dropped it back 1/4".

The rear fenders dropped about two inches with no WD and came up about 1/2" from there with the WD bars.

I added a washer to the hitch to tilt the ball back slightly, and see no changes in the measurements.

So, the front is sitting about the same height, and the back drops about 1 1/2". Does that sound reasonable?

We're taking another trip in a couple of weeks, and this one will take us by a place with scales. So, I'll get loaded measurements of the weight while we're out.

[BenK]

Add that trailers follow a smaller radius than the TV, so they often strike stuff the TV missed...

Those strikes can setup weakened innards to fail later when they contribute to heating and/or finally break a cord...

[myredracer]

Things you can do: ensure WDH is properly adjusted and spring bars are the correct rating, shocks on TV, shocks on TT, run TT tires at max sidewall psi, run TV tires at or near max psi. We have Bilsteins on the truck and shocks on our 29' TT plus Dexter equalizers, and run tires at max. psi on TT and truck rears and never any issues with bouncing under any conditions.

However, I would consider the chances of damaging the cords inside the tires from the repetitive thump, thump, thump if the height difference between joints is large enough. Has happened to me in the past in NorCal years ago before they fixed the interstate, two on our car on the same trip and one on our new truck - the cords snapped inside. If I ever come across bad expansion joints with our TT, I'm gonna either slow way down or take a detour.

Also, the repetitive expansion joints could cause the tires to heat up inside which is a major factor in killing ST tires, leading to blowouts.

Internal damage is cumulative and one day you may have a blowout for no apparent reason (TTs do suffer blowouts from time to time). Personally, based on what we've been through, I'd be concerned about excessive bouncing and flexing of the frame and what that can do.

[hvac]

I don't think the gen y hitch would work with the Andersen system. Appears you would not have any sway control.

[campigloo]

New shocks, heavier suspension both help. Your TV may be a little light as well. The only way to eliminate the porpoises is to isolate the trailer from the truck. No amount of torsion bar tightening is going to help and may make it worse. Check out the Gen-Y hitch. It’s a little pricey and weighs about 80 lbs but what a relief! It works with almost any WD hitch. It took probably 80% of it out of mine. Suspension upgrades did the rest.

[mkirsch]

JBarca wrote:

mkirsch wrote:

WNYBob wrote:
I have the same issue on I90 near Syracuse, NY (the stretch was done with new concrete a few years ago). I notice the bounce in the pickup with or without the trailer, just more pronounced with the trailer.

Between exit 39 and 40. I know that stretch well.

Pretty much any vehicle will gallop down that stretch of road. Slowing down or speeding up are the only choices, to break the harmonic.

H'mm, Odd my rig does not act up on that stretch of road. However the same interstate between exit 55 (the Lackawanna exit outside Buffalo) and the toll booths heading west will set my truck off on anything above 50mph.

There is obviously differences in the truck wheel base, weights, truck suspensions and camper setup that make some worse than others.

You 2 folks have issues between exit 39 & 40 and mine does not. But at exit 55, for sure I do have a problem there. Same road just different location.

That's odd because I've traveled 39-40 and 40-39 dozens of times since the new concrete has been in, in several different vehicles with different wheelbases ranging from compact cars to extended cab trucks, and they ALL gallop to some degree, loaded or unloaded.

The worst has been my DRW regular cab truck. It just kept bouncing harder and harder until I dropped down to 50MPH. At one point I think the wheels were coming off the ground.