16 ply vs 14 ply on steers

I run 275/70 18 ply on the trailer. I run them at 135. That seems to be where I get the best wear out of them.

 

Lowboy?

 

Yeah

 

I run 18 ply on mine, as well. When they start showing some wear, I use them on my dump trucks tag axles.

 

I had for two and a half years 14 ply my weight on the front was 10,500 and I got from Michelin 185,000 MI
Now I change them to 16 ply because the rating on the truck it says 13.2 and I have a big problem the front start shaking I move the fifth wheel more to the front and the weight now it's 11.500 nothing has changed still shaking bad I lower the pressure from 120 to 110 nothing still shaking the alignment is perfect I don't know what's the problem I spent so much money on the 16th place I want to go back and change them for 14 price but I can't so now I'm stuck please help me I don't know what's the problem.

 

sounds like one is out of round, try having them balanced