When I got my 93 (32x11.5.15) it had 32psi and rode very rough as you described. I'm running 25psi right now and the ride is much smoother. Max according to the tire is 55psi - but remember this is the MAX. Just guessing I'd say the 35psi you are running is still too much.
I arrived at 25psi by doing the "chalk test". Make a straight line across the tread of the tires from one side to the other and drive around a little so that the chalk can wear off. If the chalk wears off the tire evenly you have arrived at the proper air pressure. If it wears off in the middle of the tread but not on the outside then the pressure is too high. I'm not sure this is an exact science - some people swear by it and others say it doesn't work - but it worked for me.
Door sticker is for stock size tires, which being smaller, require more air. MAX on the tire is the most you should ever have in them..... Far too much for as light weight vehicle as a Wrangler is...
Buddah is right, chalk test is pretty good method. Keep the edges off the pavement for the best ride and to keep from under inflating them. The ride quality and handling will be your best guides. Depending on the load range of your tires and wheel width you will probably find somewhere between 26-33 psi is your best bet....
The chalk test is an old method used for decades, but take into consideration wheel width as this will effect the test. Trial and error will get you there. Seat of the pants feel it out. I run 34 psi in 33's. Seems best to me....
I have BFG KM2; 265/75-16. The weight on my front axle is 2200 lbs and 2500 lbs on my rear axle. I run 22psi on the front and 25 psi on the rear, per the load infaltion chart for my tire, I'm 16% over inflated for the road.
Good info here. I never heard about the chalk test. I have 35's the max is 65 I had it at 50 psi. After reading this thread I dropped it down to 30 psi much better ride. I couldn't do the chalk test because it rained today.
Call me lazy, a slacker, a loser but the truth is I was born to take it easy.