2011 Montana 5th Wheel Trailer Keeps Blowing Tires on Passenger Side

Question:

I have a 2011 Montana fifth wheel, total weight loaded is 14300 lb. The RV came with Goodyear Marathon 235/80 R16 E, max load is 3420 lb at 80 psi. Ive replaced the Goodyear tire with Freestar ST 235/80 R16 E, max load 3520 lb at 80 psi. I check the tires before each trip, run the tires at 75 psi and do 65 mph. I have had 5 blown tires all on the same side, passenger side. I still have rubber valve stems. Please help

asked by: Chris P

Expert Reply:

Trailer tires should always be inflated to the maximum psi indicated on the tire. If the ones you have now are rated for 80 psi then you will need to put 80 psi in them. This is because trailer tires are built with a thicker sidewall than passenger vehicle tires. If under inflated that thicker sidewall causes excessive heat build up and failure.

The valve stem material does not matter as long as the valve stem is rated high enough. For example, valve stem # AM20907 is rated for up to 100 psi.

Going to a higher capacity tire can also help. An ST235/85-16 load range F tire, # AM10501, is rated for 3,960 pounds at 110 psi. For it you would need valve stem # AM20906 rated for over 100 psi.

expert reply by: Michael H