Help please. Truck & trailer rocking when braking

[Diamondisfat]

My 2018 Ram 3500 Diesel is in the shop. They can’t figure out why, when I tow a load, that the trailer & truck rock back & forth at a gradual stop.
It’s never done this before. It has 16,800 miles on it. They say it’s nothing to do with the brakes.
It doesn’t happen when I tow gooseneck or dump trailer empty. Only when loaded does it jerk & rock back & forth at a slow stop.
I’ve unplugged the trailers to see if it’s an issue with trailer brakes but it’s not.
Thank you for the help!

 

[bm02tj]

Does it do the same with an equal load in the box making the same amount of squat
If it does it could be driveshaft angles with the diff rolling down

 

[Diamondisfat]

I don’t think so because with the gooseneck the horse was in the front. With the dump trailer ( bumper pull) the load was in the back. But I will definitely ask the shop about the diff. Thank you!

 

[chri5k]

Had nearly the same problem. My gooseneck horse trailer stops fine regardless of load using Dexter drums and backing plate / hardware / shoes. My bumper pull rocks the truck when stopping when it had TruRyde backing plate / hardware / shoes and Dexter drums. Adding .5 - 1.0 to the gain setting reduced it a little bit. Tightening the brake shoe adjustment eliminated more of the rocking. Completely eliminated rocking by replacing the TruRyde backing plate / hardware /shoes with Dexter.

 

[Diamondisfat]

Thank you!! I’ll try to go over this with the shop. It’s over my head. Hopefully they will understand.

 

[Horsehappy]

Did you ever solve this? My 2018 2500 recently started the same thing, thought it was the horses at first, but it's definitely not!