How to Correct for Frequent 5th Wheel Trailer Tire Blowouts

Question:

Maybe you can help me. I have a 5th wheel 32foot trailer that according to the specs weighs about 12,000 lbs. plus when loaded with everything. I am constantly having blowouts. Not flats but explosion blowouts. My tires are always new because Im always buying them. I check air pressure before every trip and run them at the max cold of 80 psi. The only thing I have not tried is slowing down. I run about 70-75 mph on the open highway. I have flat beds, tandem trailers and livestock trailers and I have never had blowouts like I do with this trailer. Can I possibly change to a 16inch rim and run a heavier tire? I have about 4inch of clearance between the tires and from the top of the tire to the bottom of the trailer.

asked by: Stuart

Expert Reply:

You are correct that all trailer tires should always be inflated to the maximum psi rating as shown on the tire sidewall. This is important for trailer tires since they can handle their rated weight load only when inflated fully to this maximum psi. Under-inflated tires will run hotter than they should and this will lead to failure.

However, all trailer tires, unless they are specifically rated otherwise, will have a maximum speed rating of 65-mph. Few trailer tires are rated for higher speeds than this. Running a tire, even if inflated correctly, at 10-mph over its rated speed will lead to heat build-up. This is probably what is causing the sudden explosive blowouts you've experienced.

If you are using bias ply tires you might consider switching to radials. Radial trailer tires tend to run a bit cooler than bias ply types. For example, we offer Kenda 15-inch radial trailer tire in Load Range E, part # AM10303. This and other radial trailer tires will also provide better flex and more road contact. Making a change to a larger and higher-capacity tire will increase your load capacity but unless that tire carries an official speed rating higher than 65-mph it is not advisable to run them faster. You could still have the same issue with blowouts.

For example, Taskmaster ST225/75R15 Radial Trailer Tire # TTWTRTM2257515D is a load range D tire with an M speed rating, meaning speeds up to 81-mph. Such an M speed-rated tire would be better for your application. Their larger ST235/85R16 10-ply tires are actually tested to 105-mph according to my contact at Taskmaster.

Please let me know the tire size and load rating of the tires you are using and I will be glad to check with Taskmaster for a suitable tire rated for higher speeds than 65-mph. Of course, you should always observe posted speed limits.

expert reply by: Adam R