Recommended Fix for Triple-Axle 5th Wheel Toy Hauler Surging & Bouncing

Question:

I have a 2011 Chevy 2500HD and pulling my Forrest River 395Amp XLR 5th wheel camper Im getting a lot of surging/bouncing, even over the smallest bump will cause it to start. I have measured the ride height and got it with in the specs that Reece recommended but still getting this bouncing. Do you think that the EZ Flex would help? Also the set up of my leaf spring and shackles are different than what is shown in the video for the EZ Flex. My Axle spacing center to center is 33inch I have attached a couple pictures for you to see my set up. Any help you can provide will be greatly appreciated.

asked by: Terry S

Expert Reply:

The 15,172-lb unloaded weight of the Forest River triple-axle toy hauler 395AMP is potentially getting pretty close to your Silverado 2500's towing limit by the time the trailer is loaded up, so the first thing I suggest is making sure the trailer is loaded in such a way that you have enough pin weight. Too little pin weight can lead to handling issues like sway and bounce.

5th wheel pin weight should be 20-25% of the gross trailer weight. When transporting several 4-wheelers, for example, it can take some creative loading to keep your pin weight where it needs to be. This trailer's unloaded/dry hitch weight is 2932-lbs according to the Forest River website specs. They do not specify a GVWR for this particular model but the 385AMP has a 21K GVWR.

For a loaded trailer that weighs in the range of 20,000-lbs your pin weight needs to be in the range of 4500-lbs. If not, try alternate loading to see if you can get the pin weight up and see how that affects handling. If your trailer pin weight is already where it needs to be then please disregard the above - just trying to save you some money if possible.

The first trailer modification I recommend, before cushioned equalizers like the EZ Flex # K71-657-00, is a replacement cushioned pin box such as a 5th Airborne like # 5AB-E1621-610. The linked article will help you determine if we have a cushioned pin box to replace your OEM unit. These items are replacements for specific OEM models; the unit I referenced bolts on in place of a Lippert 1621, 1621HD and other pin boxes noted on its page.

The benefit of a cushioned pin box over a quartet of cushioned equalizers is that the cushioned pin box will isolate the truck from the trailer. Cushioned equalizers do not.

expert reply by: Adam R