drive and sway

On the way home from a 4wheelin trip recently, I was getting some vibration at the rear of my XJ. I took it to Sears and had the tires rotated and balanced. No more vibration, BUT now I'm getting a sway from left to right to left going strait down the road. Kinda like there's a big tank with liquid in it strapped to my bumper with the liquid sloshing side to side. It's never done this before and I can't think of any logical reason for it to do it now. I've checked joints/bushings and all look good and are tight. Any ideas???? At first I thought it was the wind, but it was too rythmic. The only other change I've noticed is that they added air to all 4 tires. I was running 30 front/28 rear and they put 35 in all. I don't see how that could create this problem though.

Before I even finished reading the post I said "I bet they aired em up"

More air = rounder tire = smaller contact patch = less lateral stability

Pretty easy to check - Air em back down to where you had 'em, see if it goes away

Rob't

I'll give it a shot.
Thx

Make sure they tightened ALL the lug nuts!

check your sway bar links. maybe thats to obvious. ive seen many links rust away. dont know how old your jeep is but its worth a look.

Check for a bent rim. Jack the rear axle off the ground, put jack stands under it, start the engine and put it in gear. Stand directly behind each wheel and watch for "runout" (wobble). This can be caused by a bent rim, a defective tire or slipped belt in the tread, or a tire that slipped on the rim when aired down and didn't get the bead properly seated when you aired up.

Or by a bent axle (betcha didn't wanna hear that!)