What is the Best Way to Determine How Much Weight is On 5th Wheel Trailer Axles

Published 10/02/2014

Question:

We have a 2010 Jayco 39foot 5th wheel, dual axle with a GVWR of 14,950 lbs. We recently had our RV weighed fully loaded prior to traveling, and it weighed 14,620. How much weight would you deduct to compensate for hitch weight when hooked up to our tow vehicle 2012 Dodge Ram 2500 diesel 4x4 Big Horn. Jaycos formula was a hitch distribution percentage equaling 3,464 lbs.23.17 of GVWR. Also, when the RV is unhooked from the truck and supported/leveled by front landing gear structs and rear footers or jacks does this equal about the same reduction in weight off of the tires as hitch weight? The RV when manufactured came with 235/85R 16 8 ply Load Range D tires that we had problems with when 2 blew and caused damage to RV. We upgraded to same size in Load range G trailer tires just 2 years ago and in June, only one day from home we blew one tire and the next day another and a third that had cracks in the sidewall ready to blow, with damages to our RV. The tire company wont honor the warranty because we didnt carry all 4 tires back home even though we had no place to carry them and they also disagree with Jaycos formula of hitch weight. So in searching for what to do next, truck tires versus trailer tires, we came across your site and one of your experts recommended to a 5th wheel owner that your Load Range F tires are stronger than G tires and not to buy truck tires. What do you recommend?

asked by: Marty S

Expert Reply:

The most accurate way you are going to determine how much weight is on the axles of your trailer would be to go to a weigh station and have just the trailer put on the scale. This will tell you exactly how much weight is on the tires and wheels. You would want to have the trailer hitched up to your trailer and only the trailer axles on the scale.

Trailer tires should be used on your trailer. Truck tires don't have the same sidewall construction and due to this can fail.

Common things that cause trailer tires to fail are, exceeding speed rating (65 miles per hour is the rating for most trailer tires), overloading, and underinflation.

You always want to inflate the trailer tires to the max psi rating that is listed on the side of the tire otherwise the load capacity of the tire is diminished.

I attached an FAQ on trailer tires to the right that you might find informative as well.

expert reply by: Jameson C