I have a 99 RX 300 and when the car is full I hear what seems like undercarriage noise and squeaking when going over bumpy roads as if the shocks are gone. It's great on the highway. Any suggestions?

 

I have a few locations I will show where I have encountered noise on mine. Only once did I have to replace shocks (the fronts) after damaging one racing in a rally up a mountain.

First place you can start is to look at the lower rubber supports on the shocks. You can place WD-40 on these (though I recommend going through a car wash first and then spraying).

Replacing these can be a major PITA as it requires removing the springs, that without special equipment means you have to be Superman. My uncle and cousins and I have done it though.

 

On the top of the shock tower for the front shocks, open the hood and you will find this on both sides. There are 3 holes (one of which you can see to the upper left of the nut) where you want to spray in WD40. For the rear shocks there are plastic covers inside your RX in the cargo area space that you need to take off (very to find and do) to get to be able to spray in those areas.

 

Just below the lower rubber supports on the shock mount you will find this. You want to spray here and tighten this nut.

 

Another look at that same area.

 

These bushings can go on either side (front of the vehicle) and I have had to replace the entire piece. Could not get the bushing off. Tightening the screw rarely helps. If worn, this are can also affect your steering.

 

One last source of noise and aggravation that I have to deal with is this piece. You want to spray with WD-40 and also tighten the nut to the left.