op says wrote:
It's possible that when the one tire went and I put on the spare that we overloaded the other side. That tire blew out, I heard it go. My tires are E rated buy my spare was D rated. When I bought new tires I had them use the best of my old ones (an older D rated Towmax) as my spare. I guess that could have shifted weight over to the other side
A couple of misconceptions here.
A flat tire on one end of a axle or a different size tire (smaller) does't overload the tire at the other end of the axle. It can cause the tire behind or in front to take a bit more load.
The flat tire is still carry a share of the load. If its ran long enough the tire shreds till its gone then starts rolling on the wheel.
I've seen beautiful spark show at nite from my steel wheels when I pulled equipment/flatdeck/enclosed trailers for a living.
I thought I should be at 70psi, but I looked and it seems they should be around 85 (although I've been driving at 70 for a long time).
Assuming your talking about the Maxxis ST8008 trailer tire.
I've found its best to run any tire on a trailer at max sidewall pressures which lets the tire operate at its coolest especially when we get into heavier/thicker sidewalls D or E rated class tires.
Also ST tires are rated up to 65 mph max. Running at 70 mph creates more heat.
Flex from low pressures plus running at speed greater than the tire is rated/rough roads can and had has led many folks including myself to premature tire failure especially using ST tires.
If your wanting to travel at those speeds and eliminate those type issues the LT tire would be a better choice.
The forum can help you if your going that direction.
