thumping noise on uneven pavements or speed bumps from rear or trunk

[micalexs]

I am driving an 08 RX 400H. and this noise we are worrying about is making me worry if something falls off my car and becomes a road hazard to others... it sounds like the spare tire is loose, but we checked it and it is secure.. can anyone help me to figure out what that noise could be? thanks!

[carlover_rx]

hi,

you may check below :

1) Rear balance & stabilizer bars whether their is any play between joints , screws or broken rubber bus.

- Inorder to check this you need to jack the vehicle from the chassis, leaving all 4 wheels free without any load.   otherwise you wont be able to diagnose with the vehicle load on these joints.

2) Check rear suspension. You may check whether suspension bolts & screws are tightened enough. Inorder to check this you have to remove two plastic lids from the in-cabin boot compartment. Located on the rear mudguard.

2) Check Silencer bushes

3) Check whether you have placed your spare tire on correct side. Avoid any metal to metal contracts between tire RIM & tire rack.

hope this helps.

[zieke]

Joan, U don't say how many miles on your vehicle, but it could also be a rear strut. As previously stated the car needs to be on a hoist to get checked correctly, but the cost is usually reasonable to have that done. Good luck

[micalexs]

I have a high mileage on it, 138K... the cover for the spare tire moves,is that normal?

[jetfixer01]

Yes, the inner circle of the cover moves, but should lock when turned clockwise. What has been said by other folks here is correct. My guess is that it is time for new rear struts. Mine is doing the same thing. One way to check is to jack the car from the side until the rear wheel is just off the ground. Then put a long pry bar under the tire and lever the tire up & down. There should be smooth resistance. Mine has a "dead" spot before I get resistance. That is the worn out strut and the noise of it not being able to take the bumps smoothly anymore.

[gwgang]

It's the rear struts.  Struts fail gradually, and there are different sized valves inside the strut.  The small ones control small up and downs, and they fail first.  Your tires are slapping the ground too hard, thus the thumping noise.

[Robert S]

RX350 2007. I have the same problem. Loud thumping in rear when going over bumps or when turning. Suspension checks out ok. Spare tire ok. Any thoughts?