I think I solved Porpoising Problem
Being new to towing a TT ( hadna 5th wheel), the porpoising of my GMC HD 2500 was driving me crazy. Trailer weighs 8000 pounds and with the WDH set up by the dealer, the whole rig rode like crap.
It was strongly suggested that I add air bags, so I spent $400 on a set of airlift bags, and then the truck rides like a basketball....less porpoising but really bouncy ride an less stable. I tried several settings from 20 psi to 60 psi, and nothing worked. Either the truck porpoised badly or truck bounced....the wife got seasick on the last ride home.
A guy at the last campground said I absolutely should not be having these issues with a 3/4 ton truck. He said NOT to rely on the dealer set up, and he helped me review the whole set up. The dealer had set the WD hitch chains on the last link, and he told me to go to the next link on the chains. So, I was able to adjust the chains by tightening up one more link. It sure made the ride a lot better....minimal porpoising now. When I go over a bigger bump it begins to porpoise but settles down quickly...
I did measure the truck fender height at the top of the wheel well both unloaded and hitched up....based on what I have read, I think it is dialed in pretty well
Front unloaded 39 7/8" Hitched 39 3/4"
Rear unloaded 41 3/4" Hitched 40 1/2"
The front stays almost level, and the rear only drops an inch..from what I have read on this forum, and with the help of they guy at the campground, I this all is well now.
We drove it home with no psi in the airbags, just to see how it would ride without them. Anyone want to buy a new set of slightly used airlift bags? Haha
Lesson learned...don't totally rely on the dealer's set up as every truck and trailer combination is certainly unique....
It was strongly suggested that I add air bags, so I spent $400 on a set of airlift bags, and then the truck rides like a basketball....less porpoising but really bouncy ride an less stable. I tried several settings from 20 psi to 60 psi, and nothing worked. Either the truck porpoised badly or truck bounced....the wife got seasick on the last ride home.
A guy at the last campground said I absolutely should not be having these issues with a 3/4 ton truck. He said NOT to rely on the dealer set up, and he helped me review the whole set up. The dealer had set the WD hitch chains on the last link, and he told me to go to the next link on the chains. So, I was able to adjust the chains by tightening up one more link. It sure made the ride a lot better....minimal porpoising now. When I go over a bigger bump it begins to porpoise but settles down quickly...
I did measure the truck fender height at the top of the wheel well both unloaded and hitched up....based on what I have read, I think it is dialed in pretty well
Front unloaded 39 7/8" Hitched 39 3/4"
Rear unloaded 41 3/4" Hitched 40 1/2"
The front stays almost level, and the rear only drops an inch..from what I have read on this forum, and with the help of they guy at the campground, I this all is well now.
We drove it home with no psi in the airbags, just to see how it would ride without them. Anyone want to buy a new set of slightly used airlift bags? Haha
Lesson learned...don't totally rely on the dealer's set up as every truck and trailer combination is certainly unique....
