Porpoising (Bucking) Fifth Wheel
Discovered quick, simple cure for porpoising, which reduces it to a minimum when you're using cruise control. Ride with your finger on the cruise control "cancel" and press it just as you hit the exp...
Forum Discussion
RCMAN46 wrote:MrVan wrote:
We too get the "porpoising" when going over bridge joints or a really rough road elevation change. Have over 2,500 lb pin weight. Have tried several things including changing rear shock absorbers. Nothing seems to make much difference. Pulling a near 14,000 lb 5th wheel when fully loaded. Have learned to live with it and have traveled the same roads enough now so know where to slow down to reduce the drama. First few times thought the rear wheels had lifted off the road. .
You have less than 18% pin weight. That is not enough for a 5th wheel to behave.
Raise your pin weight to 25% and I bet the problem will go away.
Here is something to imagine ,the porpoising is momentarily unloading the rear axle .
That is the formula for a jack knife.
Raise your pin weight
