Another WD Hitch Question

We added Bilsteins on our truck are they are a great improvement.

I would consider installing shocks on the trailer. I could be wrong, but I *think* porpoising (if that's what is actually happening) is affected by the spring rate in the truck and trailer springs, dampening by the shocks, the distance from the truck to the TT axles and spacing between steer and drive axles. The only variable you can easily change would be the shock rate, or lack of shocks.

We added shocks to our TT last year and they make a huge difference. We did not have porpoising issues, but it greatly improves handling and gives a much smoother ride in the truck. Our TT used to bounce up and down a LOT at the rear. What I hadn't expected is that with the shocks added, the coupler on the TT moves up & down a lot less which in turn doesn't transfer anywhere near as much motion to the truck. Doesn't matter how rough or bumpy roads are now, the truck and TT now stay very level.

We went with Monroe shocks, but if doing again, I would go with the LCI shock kit.

HydrogenCyanide wrote:
Preparing for a long trip and although adjusting the hitch more did help, it did not completely eliminate the problem.

Truck- 2014 Sierra SLT with 3.42
Trailer- cougar 28rbs. About 900 lbs hitch weight and 7500 total when loaded.
Hitch- Equalizer with 12k bars

If given the choice which would you choose. New Blistien 5100 shocks or airbags? I am leaning towards the shocks as they would improve things when not towing as well, but not sure?

Any advice?

I went with The Bilstein shocks that were custom valved for my 7" to 9" Cognito lift kit. Also went with 6" Deaver Springs instead of Blocks. Lift kit and shocks made a world of difference compared to the Joke Suspension that GM installs on a 4wd!!!!! I then installed bags only to keep my rear end from squatting too much, which caused headlights to blind oncoming traffic. 25 - 28 lbs before hitching trailer. I re-adjusted my WDH after installing the bags.

Never had that problem with or without a wdh. 50 wdh's will not help if you do not have enough tow vehicle to control the trailer.

Just to be clear, when you say "back and forth" do you mean the truck is bouncing up and down?
I would first check how much weight the WDH is returning to the front axle of the TV and adjust accordingly. There are some excellent articles on RV.NET that address WDH adjustment, and I am certainly not an expert. My WDH was adjusted to return the front end height of the TV to the same as unloaded, or slightly higher. That's not my advice... Just what I did.
Once the WDH adjustment is confirmed, shocks will definetly help dampening your ride. I installed Bilstein 5100's and discovered the 17k mile OEM shocks were totally shot. I also have airbags front and rear, but these will not help at all to prevent porpoising, and will probably make it worse.

Preparing for a long trip and although adjusting the hitch more did help, it did not completely eliminate the problem.

Truck- 2014 Sierra SLT with 3.42
Trailer- cougar 28rbs. About 900 lbs hitch weight and 7500 total when loaded.
Hitch- Equalizer with 12k bars

If given the choice which would you choose. New Blistien 5100 shocks or airbags? I am leaning towards the shocks as they would improve things when not towing as well, but not sure?

Any advice?

old guy wrote:
it's called porpoising. yes there is a lot to read up on that subject. type in on the web and or go to U tube and type it in.

So did a bunch of reading. Although shocks may help, this is a brand new truck. I think I might just need to distribute a little more weight. I think I might just add another washer and see if the helps.

If not, then in will look into the shocks

Need heavier shocks on the tow vehicle.

Install some Bilstein shocks. This was the only thing that completely eliminated the porpoising for us. I tried Rancho's first but the Bils have better rebound dampening.
They improve the ride too - you wont be sorry!

I would say you need a little more tension on the bars, or if you have airbags they may be overinflated.

We have a very similar TT, I would guess your tongue weight is higher than you think. With fill propane, water, and whe the batteries where on the tongue we where at 1250-1300lbs. Yours may be different, but 900 seems low.

it's called porpoising. yes there is a lot to read up on that subject. type in on the web and or go to U tube and type it in.