Trailer bounce

nwhouston · 06-26-2018, 04:02 PM

We tow our 3124KS with a 1/2 ton pickup. Originally we towed without a WDH as the tongue weight (trailer loaded with gear in the back of the pickup) was / is still under the 600 lb allowable for my truck. Trailer towed smoothly and the truck was level. About two years ago I succumbed to internet traffic and bought / installed a WDH. Since then our trailer has been experiencing significant bounce damage. An example is the trim on the oven literally comes unscrewed. I do not have the bars set too tight (aka they are level when attached).

So we are embarking on a long trip from Texas to Virginia next week, and I am considering abandoning the WDH. That beast alone weighs over 60 lbs including the bars. And there is always the risk of the odd bite when unhooking.

Does anyone else using a WDH see similar trailer bounce effects? Anyone tried the WDH and then left it home? Appreciate your views.

Larry

**ShrimpBurrito** · 06-26-2018, 05:47 PM

My understanding is that the WDH bars should be set such that there is roughly the same amount of weight added to both the front and rear axles of the TV. I don't think it has anything to do with the level of the WDH bars. So that's one thing to check.

Second, what tire pressure are you running on the TM? And what tires (size, and load rating)?

Dave

nwhouston · 06-26-2018, 07:12 PM

When the bar tension is right they should be essentially level, at least with my BlueOx WDH design. May vary with others, but ours are right where the manual specifies, so I doubt that is the issue. Plus, the truck is correct in terms of measurements at the wheel wells both before hookup and after loading the tension bars. Even so, I have thought about letting off one chain link so there is a little less tension.

Tires run at 65 psi (D's). When hot they can get up to 70 psi, in which case I usually let the cold (aka morning) pressure drop down to about 58 psi so I stay close to 65 psi once we are warmed up down the road. I do know that too much air can definitely add to this problem. And I know that the road you are on is a big factor. So I don't know if the WDH is the prime driver of this bounce issue or not. My limited web search on the topic certainly did not find a clear confirmation, though some have suspected the same thing.

Thanks for the input. Larry

**Larryjb** · 06-26-2018, 07:16 PM

I was taught to set the WDH bars so that the TV is level, not to make the bars level. After replacing my 17 year old shocks, I think I needed to add chain link into the bars to reduce the lift. Whatever the case, it is much easier to pry up on my lift bars. Before, with the old shocks, I was having to lift the truck up a couple of inches.

Also check your tire pressure. If you have load D or E this and pumping them up to the max, you will shake the trails apart. A few members have experienced that.

**ShrimpBurrito** · 06-27-2018, 03:05 PM

The road can be a big factor. There is a section of I-405 out here that is absolutely awful for any trailer. Our trailer, as well as every other one I see on the road, bounce on this section, whereas cars are able to absorb the ripple to the point where it not noticeable.

Where pressure are you running in the TV tires?

I don't know anything about the Blue Ox....

Dave

nwhouston · 06-27-2018, 03:38 PM

Dave, I generally run at 65 psi (see my previous post above). I know the road is always a factor; and certainly overpressured tires!

I am trying to determine if using the WDH with its stiff linkage between trailer and truck is aggravating the situation. All WDH setups work on the same principle so the brand itself is not the issue. One can over or under transfer the tongue weight, and hence my comments previously about trying to get right in the sweet spot of the BlueOx lashup.

Right now I am either going to leave the heavy beast home (40% probability if I find some evidence from others that WDH's do in fact aggravate this issue) or drop the stiffness down one chain link and see what happens (60% likely as the search hits are not producing much verifiable info).

Thanks for your input. Larry

Shane826 · 06-27-2018, 05:47 PM

65psi seems really high. Imagine putting LT tires on your Chevy Malibu and airing them up to 65-70psi. It would bounce your teeth out. Also what weight are your spring bars rated for? If you’re using overly stiff bars that will cause bounce, too...

gonzo628 · 06-28-2018, 02:03 AM

Quote:

Originally Posted by nwhouston

We tow our 3124KS with a 1/2 ton pickup. Originally we towed without a WDH as the tongue weight (trailer loaded with gear in the back of the pickup) was / is still under the 600 lb allowable for my truck. Trailer towed smoothly and the truck was level. About two years ago I succumbed to internet traffic and bought / installed a WDH. Since then our trailer has been experiencing significant bounce damage. An example is the trim on the oven literally comes unscrewed. I do not have the bars set too tight (aka they are level when attached).

So we are embarking on a long trip from Texas to Virginia next week, and I am considering abandoning the WDH. That beast alone weighs over 60 lbs including the bars. And there is always the risk of the odd bite when unhooking.

Does anyone else using a WDH see similar trailer bounce effects? Anyone tried the WDH and then left it home? Appreciate your views.

Larry

Hi Larry,

I had come to the forum with that very problem a while back. My trailer was getting beat up on every trip (usually less than 200mi one way). I thought my WDH bars (1k) were the issue and tried towing without. While the perceived outcome was that it was a touch less harsh, the reality was that my trailer was still getting beat up pretty badly. I took the trailer to the local tire place to have the wheels balanced (not normally needed on a trailer, but I had to rule it out (for my own sanity). The tire shop was unable to balance the tires and advised that my wheels were non-concentric. They explained that steel wheels sometimes get stamped outside of true dead center. their recommended fix was Alloy wheels which are less susceptible to the issue given their manufacturing process.

After our most recent trip had half of our interior hinges work themselves loose, and the oven door came off (among other things). We decided to pull the trigger on the alloy wheels and new tires. I took the trailer on a quick 20-mile jaunt and (it may be subjective) but I feel like the difference is night and day. It no longer feels like my trailer is shaking apart.

-Ronnie

nwhouston · 06-28-2018, 07:44 AM

Thanks for the great input overnight! Good ideas to pursue.

First the BlueOx and its 1000 lb bars. As one of Bill's old posts says, a fully loaded 3124KS has a tongue weight at or north of 700 lbs. Hence the 1000 lb bars. But I may be pulling them up more than needed. My comment about horizontal was not literal, but they do need to be pulled up so they are stiff and causing the truck to be level. At that point they are close to level (got this from calling BlueOx when I was first setting it up). But dropping back one link will not create a 'soft' lash up, so right now that is my plan. (I have thought about getting a 750 lb set to try, but the cost is enough to drive me to look at other things first. I am reweighing after load out this trip to see if something has changed).

I take my rims to Discount Tire to mount tires (two sets so far) and have had no comments on the rims. But maybe that is the right step when we replace the tires again next year. I go three years and change regardless of mileage.

We take off Tuesday, so for now I think the 'one-link' less tension is my best plan. If we find oven door parts on the floor again after day one, I may drop the WDH into the truck bed and pull with the conventional receiver hitch.

Thanks for input. Larry

**Bill** · 06-28-2018, 09:36 AM

Quote:

Originally Posted by nwhouston

[The tires on my 3124] run at 65 psi (D's). When hot they can get up to 70 psi, in which case I usually let the cold (aka morning) pressure drop down to about 58 psi so I stay close to 65 psi once we are warmed up down the road. I do know that too much air can definitely add to this problem.

Tire manufacturers specifically tell you not to de-air the tires to compensate for the warming effect. The pressure rating on the sidewall, and in the load inflation tables, is the manufacturer's specified COLD PRESSURE, and the tire design takes into account the warming effect. The manufacturer is careful to say that COLD does not mean "refrigerated". It just means "not yet driven on today". Remember that by deflating from 65 psi cold to 58 psi cold, the tire's load rating for a 15-inch Goodyear Marathon drops by two hundred pounds per side.

Quote:

And I know that the road you are on is a big factor.

That's for sure. On our recent trip from Arizona to Maine, we traveled on 50 miles of old concrete road in Colorado - the kind of road where they poured a series of concrete slabs on the ground, separated by narrow expansion joints, and the concrete settled unevenly as it cured. The result is a POUND POUND POUND as you traverse the joints. It did quite a bit of damage to our TM. The real point I'm making, though, is that we have towed our TMs for somewhere around 100,000 miles, always with a WDH, and although we've had some screws shake out over the years, the pounding problem never really showed up until we hit this long stretch of bad road.

Our experience suggests that the WDH is not a culprit in the pounding. I have always felt that a lot of the problem is due to the fact that the TM doesn't have shock absorbers like your tow vehicle does. This, combined with the pounding road, is what does the damage.

Bill