I have a 98' 4runner with ~117,000 miles. The vehicle has 1 inch lowering springs (from the previous owner) and relatively new Bilstein shocks. Recently, the vehicle has demonstrated body sway on the freeway at speeds above 65+ mph. This is especially noticable if there is wind. The sway is like a rocking motion. I have also noticed that the rear end feels soft during freeway turns (i.e. offramps etc.) I wonder if the springs are wearing out with 100,000+ miles but I thought springs basically lasted forever. I also considered adding sway bars (ft and rear) to combat the swaying problem (I primarily drive on streets and occassional gravel roads), but am unsure if this will address the stability issue. If the problem is the springs, I will likely replace with the stock springs; do the Bilsteins shocks work well with the stock springs? Any thoughts on these issues would be greatly appreciated!

 

How's you tire inflation? Also I have a '98 as well with oem sway bars allready. Is it possible you have them but are broken or disconnected?

 

I thought tire pressue may be an issue as well but they measured 34 PSI in all 4 tires. I previously inspected the OEM sway bars/bushings and they looked to be in decent shape.

 

It's possible to have a bad shock as well. Also, are you carrying any more weight in the back. IE: tools, amps, speakers etc? Or perhaps a car top carrier? Springs will sag over time as well.

 

Thank you for the suggestions. Unfortunately, I do not carry any additional weight in back. However, the previous owner had a heavy speaker box for the first 70k of the vehicle's life; I wonder if that could have shortened the springs useful life? The springs do not appear to be sagging as the front seems level with the rear....