Trailer Tires on a 4-Horse Trailer Keep Blowing

Question:

I had my 2nd tire blow today on a 4 horse trailer. We are towing at 65-70 mph, with a large diesel RV. The trailer was put into service 4/11 and the RV I tow it with has about 38000 miles, so the trailer has about 30,000miles on it. The trailer loaded is about 10,000 lbs. is it time to rrplace these tires? What is the most heavy duty tire I can buy?

asked by: Katrin T

Expert Reply:

First we need to determine why the tires are blowing. Trailer tires are particularly susceptible to heat. This is because trailer tires are built with a thicker sidewall than passenger vehicle tires to handle more vertical load. If under inflated, the thicker sidewall will generate excessive heat and can fail. Always make sure the tires are inflated to the maximum psi as indicated on the tire.

Speed can also be a factor. Most trailer tires are not rated for such high speeds. The tires we carry max out at 65 miles per hour. Other trailer tires are well below even that. More speed does increase the heat: the mortal enemy of tires.

And it is also possible the tires are overloaded if they are not the proper load range. To determine the best tire options for your trailer I will need to know the size. The page you came from is for a 4.80/4.00-8 Bias Trailer Tire and wheel combo # AM30020. These seems very small to me for a 4-horse trailer since horses are heavy depending on age and breed, some heavier than others.

If you can verify the tire size I can make some recommendations. You will also want to check the capacity of the trailer (should be on a sticker or plate somewhere on the frame or tongue) so you can be sure you are not exceeding it. Adding higher capacity tires will not increase the trailer capacity. The trailer capacity is set by the axle and trailer construction.

expert reply by: Michael H