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D-C-Johnson's avatar
D-C-Johnson
Explorer
Jun 20, 2018

Bouncy issue

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.
  • D-C-Johnson wrote:
    I don't know exacts, but loaded weight should be roughly between 9000-9500lbs and my tongue weight around 1000lbs. The TT does not have shocks just leaf springs. I am running my WDH(blue ox swaypro2) on the 9th link as my dealer said that was recommended and the truck only sags at most one inch and the TT runs level. I didn't have this issue with my previous TT which was 32ft and 7000lbs loaded with at most 900lbs tongue weight.


    1. You should get some actual scale weights. They might surprise you.

    2. The number of chain links varies with every truck / trailer combo. There is no standard number of links. I installed my BlueOx Swaypro 1500, and from what I remember of the installation manual, it said start with link 7, then adjust up or down as necessary. Link 9 sounds a bit weak on weight distribution. Without accurate weights or using fender well measurements, your just guessing on WDH adjustments. Note: Tongue weight is not a constant number. It goes up and down during every trip. Adjust your WDH to support your highest tongue weight.

    3. Is your bouncy ride with or without water on board? I noticed in the specs, your grey water capacity is 78 gallons. That suggests more than one grey tank. Mine does, and my on board water levels can change my tongue weight by as much as 250 lbs. My fresh tank is behind the axles and takes weight off the tongue, my black and grey tanks are directly above the axles and have little to no effect on tongue weight, and my galley tank is way up front, where it adds a lot of tongue weight. My loaded weight is 7400 lbs and my tongue weight can be anywhere between 975 and 1225 lbs.

    Your bouncy ride could be caused by a combination of several things. Springs, hitch adjustment (ball height, chain links), shocks, tire inflation, trailer loading, bad roads, etc.
  • It's probably hitch flex. I assume you have the factory GM hitch receiver? It is not stiff enough to properly transfer the loads from a good WD hitch, so as if flexes, you feel it as bouncing.
  • 37' and 7256 lbs is not much weight for that long of a TT. I'm guessing the OP's getting some flex at the tongue. This is what happens when you combine Ultra Lite and ultra long.
  • goducks10 wrote:
    37' and 7256 lbs is not much weight for that long of a TT. I'm guessing the OP's getting some flex at the tongue. This is what happens when you combine Ultra Lite and ultra long.


    I hope that isn't going to be a just deal with it issue goducks10. I am going to start with changing rear shocks on the truck and move some weight forward, I hope that fixes most of it, also probably going to replace the factory hitch with a class V, looking at https://www.realtruck.com/curt-class-v-trailer-hitch/15300.html?utm_campaign=product_ads&utm_source=google&utm_medium=cpc&utm_content=867667&gclid=EAIaIQobChMIgbLOh4_j2wIVArXACh1PHAXvEAQYCCABEgIIuPD_BwE more for a comfort after reading up on the factory hitch issue even tho mine looks good with no signs of the issue.
  • My rig is almost identical to yours. You’ll probably never get all of the porpoising out of it but you can eliminate most of it. First, get top notch shocks. Big difference. I added an inexpensive gizmo called StalbleLoad. It fits on the spring pack to engage the overload spring. It can be disengaged when not towing and is pretty effective.
    And the last that really gets poo pooed on this forum is a Gen-Y hitch. It comes on it’s own stinger and your wdh head bolts right to it. What it does is isolate the trailer from the tv. It’s a rubber torsion device that gives instead of transferring the bounce to the truck. I don’t know how to explain the physics but I do know it works. A bit pricey at 5 bills and kinda heavy but soooo worth it. Not only has most of the porpoisin gone away, but on small to moderate size road bumps I don’t feel anything after the truck goes over the bump. I can also tell a difference in the trailer. Things are not jostled around so much. The company claims it’s also easier on the tranny because it doesn’t jerk it back and forth so much. Check it out, it’s worth a google search.
  • D-C-Johnson wrote:
    goducks10 wrote:
    37' and 7256 lbs is not much weight for that long of a TT. I'm guessing the OP's getting some flex at the tongue. This is what happens when you combine Ultra Lite and ultra long.


    I hope that isn't going to be a just deal with it issue goducks10. I am going to start with changing rear shocks on the truck and move some weight forward, I hope that fixes most of it, also probably going to replace the factory hitch with a class V, looking at https://www.realtruck.com/curt-class-v-trailer-hitch/15300.html?utm_campaign=product_ads&utm_source=google&utm_medium=cpc&utm_content=867667&gclid=EAIaIQobChMIgbLOh4_j2wIVArXACh1PHAXvEAQYCCABEgIIuPD_BwE more for a comfort after reading up on the factory hitch issue even tho mine looks good with no signs of the issue.


    Yup thats the hitch I got. Why did I overkill so much for my 1500 silverado? Because it was cheaper then the lower grade model.

    I did the shocks first. The porpoising improved but not all. When I changed the hitch it all went away.

    Im on 9th link myself. I have head tilted as far back as it can go with all 7 or 8 washers in there. 740 tongue weight.

    Its hard to get all the weight restored to front of truck on the GM's with the torsion bar front suspension. So dont try to over chain the wd bars.

    Scale it when done. get 3 passes as outlined here.

    The only goal with wd hitch is to get the front close to truck alone weights..

    http://towingplanner.com/ActualWeights/TravelTrailerCatScales
  • I’m going to agree with gritdog that it’s the weight distribution of the trailer. Even with proper tongue weight if you have a lot of weight forward and aft instead of centralized this is what you get. I did 20k towing miles with a 06 2500 Silverado and factory hitch wth 1200lbs of tongue weight without porpoising and bounce. Most of that was with a standard round bar WD and no sway control.

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