I bought a set of Dunlop Radial Rover RV XT 265/75R16E at Sears and placed them on my stock 2001 Ford Super Duty 3/4 ton 4x4. The truck had the stock Firestone Steeltex tires prior to installing the Dunlop RV XT's. It handled fine with the old steeltex. But the new Dunlop's immediately made it tough to keep the truck going straight down the rode. The best way I can explain the symtoms is since installing the new tires, the truck is slow to respond to steering corrections. For example when going through a gradual left turn at higway speeds, I will turn the steering to the left for the curve. I feel a pressure build up on the steering wheel from my correctionto the left and by the time the truck responds it is darting to far to the left and I have to pull it back to the right. Then I'm going to far to the right and I have to try to bring it back to the left and it becomes a battle to keep it in my lane. The truck doesn't pull to one side or another like it would if the alignment was off. Sears automotive checked the front end and steering linkage and it is fine. Sears rotated, rebalanced the tires, and lowered the air pressure to 60 psi. But the truck is still difficult to handle.
What could be the problem?
Note: I noticed a couple of the new tires took much more wheel weights to balance than the previous old steeltex tires.