Bouncy issue

[D-C-Johnson]

Input needed, I have a 2018 Kodiak 331bhsl
WEIGHTS
Average Shipping Weight (lbs.) 7,256
Dry Hitch Weight (lbs.) 880
Cargo Capacity (lbs.) 2,424
MEASUREMENTS
Height 11' 2''
Length 37' 3''
My wdh is a blue ox swaypro 2 1200lb bars
TV 2005 Silverado 2500hd duramax CC 4x4
w/ Toyo open country rt 295/55r20 10 ply with 65psi

The issue I have isn't sway it's porpoising when I encounter multiple dips and or humps I get alot of bouncing. I have tweaked weight front to back and back to front with minimal noticeable difference, any input on this to improve my tow is greatly appreciated.

[lawrosa]

D-C-Johnson wrote:
Input needed, I have a 2018 Kodiak 331bhsl
WEIGHTS
Average Shipping Weight (lbs.) 7,256
Dry Hitch Weight (lbs.) 880
Cargo Capacity (lbs.) 2,424
MEASUREMENTS
Height 11' 2''
Length 37' 3''
My wdh is a blue ox swaypro 2 1200lb bars
TV 2005 Silverado 2500hd duramax CC 4x4
w/ Toyo open country rt 295/55r20 10 ply with 65psi

The issue I have isn't sway it's porpoising when I encounter multiple dips and or humps I get alot of bouncing. I have tweaked weight front to back and back to front with minimal noticeable difference, any input on this to improve my tow is greatly appreciated.

Its the hitch on the truck. Its most likely attached to bumper like mine was at two points. This causes the WD hitch to flex and not distribute the weight.

It has those two bolts on the bumper because they've cheapened the receiver. It no longer is strong enough by itself to do the weight distribution from the hitch to the frame rails.



Needs to transfer that force to the bumper. The bumper is designed to take a hit from different direction, so will bend in the direction the receiver pushes.



Then the bumper will try to transfer that loading to the brackets holding the bumper to the frame rails.



This "food chain" will bend the bumper and brackets so that not enough of the WD from the hitch is transfered. Why many can't drop their TV's front end wtih a WD hitch and WD bars...no matter how heave a bar and how many links tightened.



For those who still don't believe, take a 2 inch square bar about 6 feet long. Shove it into a NBS receiver and lift. Note that the receiver tube will bend towards the bumper, the bumper will move up and bend. It's brackets are behind so can't see them, but they will move before transfering enough load to the frame rails.



Also look at other NBS receivers that have been used to tow heavy. Most all I've seen in parking lots are bent either downwards or upwards.

I replaced my hitch and bilsteins and that porpoising bunking bronco ride went away

Read here

https://www.gm-trucks.com/forums/topic/28680-receiver-hitch-failure/

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29612580/srt/pa/pging/1/page/1.cfm

[SidecarFlip]

bartlettj wrote:
I think you need new shocks on the truck first of all. That's a pretty long trailer for an older 2500hd.

+2..

Time for new HD shocks.

[bartlettj]

I think you need new shocks on the truck first of all. That's a pretty long trailer for an older 2500hd.

[ScottG]

I've had that issue in the past!
Having too stiff of spring bars ( I dont think that's your issue), having them adjusted too tightly or having the front of the trailer nose high aggravates it the most in my experience.
One of the biggest improvements you can make is to install some Bilstein shocks on the back (and front for improved ride). They have the best rebound dampening I have found and that will control porpoising. I can actually feel them hold the back down when it wants to bounce.