Front end bounces horribly when going over 55 mph
Hello everyone,
I have gone through most of the posts for cab over bouncing and I can't seem to find a solution that fits my current set up.
I have a 2015 GMC Sierra 1500 5.3 L V8 4X4 Crew Cab.
The slide in camper is a sun lite pop up but I am not sure of the model number or exact weight. Unfortunately the guy I bought it from didn't have any info on it. He said he though it weighed roughly 1000 lbs.
What I do know is the camper only sticks out a few inches past the tail gate so it's roughly 6ft long inside the bed. My bed is the 5.5 ft (the shortest bed they have in a 1500). I have the Happijac camper tie downs installed in between the cab and bed and tie downs mounted to the back bumper. I used a regular set of turnbuckles off of amazon. They are Brophy Machine Works brand and have a tensile strength of 2100 lbs.
The issue I am having is that when I get up to 55 mph or higher the front end of my truck starts to bounces uncontrollably. I have tried adjusting tire pressure and tightening the turnbuckles but neither of those things helped at all. Any other pointers? is the camper to heavy for my truck? Is it a WD problem?
Here's a pic:
Not likely the issue at all.
I feel like I asked a couple few questions you haven’t answered. As have others.
what’s under it for suspension?what you got for tires and pressure?
what kind of road, asphalt or concrete?
how long how far how many roads and miles have you driven it? Or any other heavily loaded truck?
I can get an almost empty truck bouncing pretty good at the right speed on the wrong concrete highway. Yet never had even a severely overloaded pickup bounce like that on smooth asphalt. Concrete panels create ridges at each panel joint where they’re saw cut, when the edges swell or curl. Sounds like what you’re experiencing, but until you provide more insight, can’t tell.
Concrete panels as in the road surface. Many highways are poured concrete, which have an expansion joint, or a cut line, at regular intervals to control cracking and expansion.
These regularly-spaced seams in the concrete can set up a harmonic bouncing in your vehicle at certain speeds and/or weights. Asphalt over concrete will do the same thing because the seams are still there under the asphalt.
Now that you know what to look for you can seek out a smooth paved road that isn't asphalt over concrete, where you can go 55 or faster, to see if it's the truck or the road.
You don't have to be overweight or dangerously light on the front of the truck to have this problem. You just have to be balanced wrong. Hence why I still think it's a weight transfer issue. In a nutshell: The weight of the 1000lb+ camper sitting at 2-3' behind the axle has lifted just enough weight off the front of the truck to make it sensitive to road seams...
One other thing that I don't think we've touched on: Is the bouncing uncontrollable or is the truck uncontrollable?
