Hello,

I've been a lurker for a few years and am finally posting for the first time. I appreciate the vast amount of info this forum provides.

The wifes DD is a 2000 RX300. We currently have a little over 160k on it and it is still going strong. However, being in the rust belt is slowly starting to take its toll on the exterior.

I noticed this part dangling underneath it yesterday. I am not exactly sure what it is. It is like a bushing of some sort that mounts to the exhaust on the opposite side of the rear 02 sensor next to the drive shaft. Does anyone know what it is? If my pic doesn't show up due to lack of posts I will describe it.

It has a hockey puck shaped bushing that attaches to a bracket that mounts to the exhaust. The bracket being what rusted through leading to it falling off. Once I touch it and moved it a little it came loose. I'm glad I found it before it fell off. Anybody know by chance?

 

If I had to guess I'd say that it is either a redundant muffler hangar OR, if the end is a big piece of rubber, then it is probably a tuned mass damper. Auto companies use these more frequently now days to tune out the natural rattles and hums of a vehicle. The mass is sized to exactly absorb the frequency of a specific rattle that may be problematic or annoying. The RX300 has a few of them to make it an ultra quiet ride.

 

Yeah that end piece is rubber but it is heavy so it might have a chunk of metal in it. Thanks!

 

Same thing happened on my 2002 RX with 88,000 miles on it.
I too noticed the "tuned mass damper" dangling form the bottom of my RX.
I drove to my local Toyota dealer and they removed it, Looking at the damper I was lucky it just didn't fall out on the street. The mounting bracket was so rusted that it just gave way, I am carrying it around with the intent of next time the vehicle is up in the air I can see if there is some way of re-attaching it (even if we have to fab a new bracket).
I have not noticed any additional noise or vibration in the vehicle since the damper was removed.

 

Yeah if it fell off at speed on a highway it could easily become a dangerous object. Anyways, unless the change is fairly noticeable I suppose we'll just leave it be.

 

It is attached to the exhaust to elimate harmonic vibrations and prevent noise in the cabin....

 

I had my dampers off even when my modified exhaust was much quieter and didn't really hear any difference before or after.

 

The harmonic damper is to cut down the vibration (we all agree on this).

Caution .. boring stuff

The vibration (frequency and mutiples) can produce sound/noise [if it is audible or not]. The vibes can travel by air and since the exhaust is mechanically coupled to the RX, they can travel through the body .. depending on the frequency can be felt or heard or vibrate something else (which can then produce audible sound ... example stuff in the glove box typically vibrates due to engine idle).

The other aspect that no one mentioned is the physical stress on the object due to vibration (standing waves).

Final note The damper location and mass are calculated (tuned). A retro fit (adapted fit) may not be a precise solution. If you put in a different exhaust then again OEM version may or may not work.

Now the vehicles are old but they are part of warranty.

Salim

 

I just looked under my car, because i've had an increase in vibration throughout the car, and it's still there. It is a lot bigger than your picture makes it look. It's a big chunk of metal.

 

Mine fell off years ago. It could kill someone if it hit them.

 

Where under the car should it be? I'm curious, as I want to look under my RX to see if I still have it.

 

Just follow the exhaust, it is an appendage .. hard not to miss, unless it has fallen off <- due to corrosion.

Salim

 

Ok, thanks. I'll check it out tomorrow during the day.

 

Borrowed from other threads.

 

Get under the car on the passenger side and it should be right there on the exhaust.