What Causes a Trailer to Bounce/Porpoise on Highway

Published 12/18/2019

Question:

I have a 2016 Yukon with a HD Tow Package and an Air Leveling Kit. I tow a 28 ft trailer and I am getting some bounce down the highway. Not sway but bounce. Would a rear Timbren System help to eliminate some of this bounce, and could I install this system with a Air Leveling system.

asked by: Joe L

Expert Reply:

Porpoising (bouncing like you described) and sway are both commonly caused by the same thing when towing and that is not enough tongue weight for the trailer relative to the total amount of weight the trailer weighs. You need the tongue weight to be between 10 and 15 percent of the total trailer weight for the porpoising to stop.

Suspension enhancement would actually cause the bounce to be more severe so I would not recommend going that route. I'd get the tongue weight checked and also make sure the trailer is sitting perfectly level when towing and you'll have the problem taken care of.

I also attached a link to a page that shows how to pick out the correct rise/drop ball mount as well.

expert reply by: Jameson C