How do you fix a bounce?

Beachnut · 12-31-2010, 08:27 PM

I have recently purchased a Outback 230RS and LOVE it! However, when I tow it with my 2005 Chevy Silverado 1500 4x4 Z71, with a reese load leveling hitch with 1000 # bars I often get this bounce. The best description I can give for this bounce is the hitch goes down, as the front of the truck, and back of the trailer is kind of moving up, then visa versa, then this cycles back and forth where the hitch goes down again, and ends go up. It is not a radical bounce, just noticeable, especially if you look in the side mirror and see the trailer going slightly up and down. It does level out after a few ups and downs and stops bouncing, but any bumps, or slight dip starts the cycle all over again for a bit.

Would stiffing up the back suspension on the truck with air bags stop this "bounce"? (Any paticular brand of air lift bag any better than others for this problem?) The truck really does not drop down that much with the trailer load added to it, it obviously can go much lower as seen in the real large bump / bounce effect. I tried maxing out the truck tires to 80 PSI all around but it did not help much, (Goodyear AT LT tires).

Any thoughts on how to fix this would be great!

Beachnut

Festus2 · 12-31-2010, 09:12 PM

I think that if you are travelling down any concrete/cement freeway, you are bound (sorry, no pun intended) to get some "bounce". Every time you go over one of those dividers/separators, it may feel like you have a flat tire. The bounce seems to be magnified by the time it gets to the TV ; and, as you described, one end goes up and the other comes down. I find the bounce is increased when you are driving in the far right-hand truck lane and less as you move out to the left-hand lanes.
Not sure whether or not air-bags or other suspension aids will totally eliminate this bounce but they may help reduce it to various degrees.

tocools · 12-31-2010, 10:02 PM

try going up one more link on your WD chain it may make a big differance.

campingcpl · 01-03-2011, 05:07 AM

Like Festus said you will get it no matter what you do. I added load adjusting shocks to our 1/2 ton and also adjusted the leveling bars and that reduced the bounce a little but didn't eliminate it. In the spring I will be upgrading the suspension on the trailer with the Dexter EZ-Flex system which I have heard from several people that it will also help.

Seann · 01-06-2011, 09:28 AM

It is called porpoising Keep tightening up your weight bars till it stops.

campingcpl · 01-07-2011, 07:04 AM

Quote:

Originally Posted by Seann

It is called porpoising Keep tightening up your weight bars till it stops.

The problem with that is there is the potential of overloading one of the axles on the trailer and possibly causing tire failure. I've worked in the RV industry a long time and have seen this happen. The leveing bars are desinged to distribute the weight evenly between the trailer and tow vehical. Tightening the bars up to much puts additional weight on the rear axle of the trailer and additional weight on the front wheels of the tow vehical. Not having the bars tight enough will cause to much weight on the front axle of the trailer and more weight on the rear tires of the tow vehical and will give you that light front end feeling or feeling that the steering is not very responsive. In my personal expreriences of working in the RV buisness, I have seen people blow out tires and even bust mounting bolts on the hitch from having the bars to tight. That's just my 2cents worth.

Beachnut · 01-08-2011, 11:04 AM

Thank you ALL for the great input! Now I know what i am experiencing is something some what "normal", and is called "porpoising"! We just got back from 19 days in the Mojave desert, (where it rained for 6 straight days). I DID notice that on the asphalt roads over there and back that i did not have hardly any porpoising. It is most noticeable on concrete freeways with the many concrete seams, not on asphalt Hwy's.

On the leveling bars.... How do you know what is too tight, or loose?

The dealer that set the load leveling hitch up when we bought the Outback said to leave one link hanging, so I am hooked up to the 2nd link from the end. It does require using the bar to lock the chain / bar into position so there is a fair amount of tension on the bar, but not a whole lot of tension. If I tried to go to 2 links hanging, or hooked up to the 3rd link down, now that would be quite a bit of tension, and some good "umph" to hook it up.

Beachnut

campingcpl · 01-10-2011, 08:32 AM

Quote:

Originally Posted by Beachnut

Thank you ALL for the great input! Now I know what i am experiencing is something some what "normal", and is called "porpoising"! We just got back from 19 days in the Mojave desert, (where it rained for 6 straight days). I DID notice that on the asphalt roads over there and back that i did not have hardly any porpoising. It is most noticeable on concrete freeways with the many concrete seams, not on asphalt Hwy's.

On the leveling bars.... How do you know what is too tight, or loose?

The dealer that set the load leveling hitch up when we bought the Outback said to leave one link hanging, so I am hooked up to the 2nd link from the end. It does require using the bar to lock the chain / bar into position so there is a fair amount of tension on the bar, but not a whole lot of tension. If I tried to go to 2 links hanging, or hooked up to the 3rd link down, now that would be quite a bit of tension, and some good "umph" to hook it up.

Beachnut

There are several different ways to tell if you have to much or to little tension on your bars. The easiest but not the most accurate is by measuring your TV. Park it on level ground unhooked from the trailer and measure the front (measrue to the top center of the wheel wells) and then measure the rear. Then connect the trailer (with bars) to the TV and remeasure the TV again. The front measurment should be the same or slightly less then your first measurment. The rear measurment should be close to the front measurment or slightly higher and your trailer should be setting level. This is the most common way and the way a "good" dealer or hitch shop will explain how to set up your trailer. When doing this you also need to make sure you have your trailer load just like you would for a trip. The extras you put into it can change your set up slightly. The other way and that is a lot more accurate but not as practical is to take the truck and trailer to some place that has a set of scales and weigh each tire of the TV and trailer. The load should be spread evenly over all the tires. A lot of your big truck scales can give you per axle weights whitch will work too.

I know when the dealer set up our new hitch when we bought the bigger trailer they did not set it up correctly. They didn't put any pitch in the hitch and did not have the bars adjusted correctly. I said something to them about it and they said that was the way they always set it up. Well I worked in a hitch shop for 5 years and I never seen a hitch set up the way they did mine. So after I got home I took the hitch back apart and set it up using the starting point in the "directions" for the hitch and then made a few adjustments from there and it was a much better ride.

As for trying to get the bars on with out having to be a strongman, do you hook up the TV and trailer then raise the tounge up to hook up your bars? I have the Equal-i-zer brand hitch and I very rarely have to use my helper bar to get my leveling bars on after raising the tounge jack. By raising the tounge and the back of the truck you reduce the angle at whitch your hitch head is set at thus bringing the end of the bars up to the a-frame of the trailer. If you haven't tried this it would be worth trying.

Here is a link to show how to set up a weight distributing hitch from start to finish step by step. I hope this helps you out.

http://www.etrailer.com/tv-weight_di..._ford_van.aspx

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