When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yet another “unidentified sound coming from the rear of the vehicle” thread…
The last few weeks I’ve been hearing a rattle/thumping/knocking in the left rear of my 2013 RX350 (62k miles, AWD, does not have air suspension). The rattle occurs at low to moderate speeds on roads when going over small bumps that the suspension mostly absorbs (i.e., barely felt in cabin). Not as noticeable at higher speeds, but that may be due to higher road/wind noise.
It’s not the rear hatch, sunroof, or anything under to cargo floor cover -- I pulled out everything in the cargo area at one point, including the plastic molded tubs. The spare tire is bolted down tight.
Yesterday I rode in the back while my wife drove around the neighborhood, and I believe I’ve isolated the location to the upper area of the left (driver’s) rear wheel well, maybe slightly ahead of and below the gas door, but certainly not inside the cargo area. It doesn’t appear to be the rear door latch as someone else here found -- I put tape on the latch and pressed on the door while driving and sound continued.
I don’t think it’s the sway bar links. I’ve dealt with those before in two previous vehicles and the both the sound and situation are different. In both of those cases I was able to recreate the “clunk” sound by lifting up on the fender, or pulling into the driveway while turning. This is different.
Not sure how old the shocks are but they are not original. The vehicle has 62k miles (I bought at 46k from CarMax), and the Monroe OESpectrum shocks were installed at some point prior to my purchase, so probably 25k-30k on the replacements.
I’ve pulled the wheel off and looked at the shocks, etc. No obvious issue there, but I’m not a mechanic so I could easily be missing something. I need to get under the vehicle and look at the bushings on the rear trailing control arm.
So, what does that leave? Shocks possibly, control arms, worn bushings on the stabilizer bar, what else? How can I definitively identify the problem? I know I may have to take it to a garage or suspension shop and have them inspect it, but I’d like to have a fairly good idea of what the cause actually is before going to them for verification.
Control arm bushings could indeed be suspect. But so could the sway bar link bushings. I would not rule them out until I had a good look at them. On some vehicles you can disconnect the sway bar links and then drive around to see if the offending noise disappears. Not sure if the RX350 falls into that category though.
Control arm bushings could indeed be suspect. But so could the sway bar link bushings. I would not rule them out until I had a good look at them. On some vehicles you can disconnect the sway bar links and then drive around to see if the offending noise disappears. Not sure if the RX350 falls into that category though.
Yeah, I was going to look more closely at the link when I checked out the stabilizer bushings. And I may have been too quick to discount that as the problem -- just because I've heard it sound one way in one situation doesn't mean it might not sound different in another. It'd actually be nice if that was the problem since it's a relatively cheap & easy fix.
It is probably the infamous rear trailing arm bushings. There are a few threads on this causing a clunk. You cannot just replace the bushing, but must replace the entire trailing arm. However, now aftermarket parts are available for much less money than OEM. Mevotech makes them.
Just before I changed my rear shocks, I was hearing a similar sound on the driver side rear. It turned out to be the rubber bushing on the upper shock bolt was worn/damaged and causing a noise. I couldn't see the damage until the bolt was out of the shock. Worth a look, but most likely the very well documented issue clutchess mentions above, since your shocks are fairly new.
Just before I changed my rear shocks, I was hearing a similar sound on the driver side rear. It turned out to be the rubber bushing on the upper shock bolt was worn/damaged and causing a noise. I couldn't see the damage until the bolt was out of the shock. Worth a look, but most likely the very well documented issue clutchess mentions above, since your shocks are fairly new.
If I find nothing else, no harm in trying that. Thanks for the idea!
It is probably the infamous rear trailing arm bushings. There are a few threads on this causing a clunk. You cannot just replace the bushing, but must replace the entire trailing arm. However, now aftermarket parts are available for much less money than OEM. Mevotech makes them.
Update:Jacked up the vehicle, checked the suspension, pulled the wheel off and checked some more. The sway bar links (both sides) seem good with no rattle/looseness and the boots look intact. There is some cracking in the trailing control arm bushing when it's not under compression (see photo), but I don' know how much, if any, is normal. Shocks look a bit rusty but not leaky as far as I can tell. I didn't pull the shock on that side off, but from what I could tell it looked like the bushings were still in good shape.
Outside, on jack stand Inside, on jack stand Outside, under compression
Could it be coming from inside the cabin by chance? Just curious. My rear seat sometimes offers an interesting noise or two if folded down or has recently been moved....seriously spit balling now though.
Could it be coming from inside the cabin by chance? Just curious. My rear seat sometimes offers an interesting noise or two if folded down or has recently been moved....seriously spit balling now though.
Pretty certain it's not. I laid down in the cargo area and on the rear seat back and was able to isolate the sound to somewhere in the wheel well area.
Well, we can rule out the stabilizer link as the source of the noise. I decided to take the one on the left (driver's) side off and see if the noise went away while driving around the neighborhood. Having replaced about a half dozen links before (but usually much older) I knew there was a good chance I wouldn't be able to take it off without tearing it up, and I was right. This one was being a *real* pain in the ***, and I eventually just cut it off with a sawzall and replaced it with a Moog link. The old one appeared to be in good shape on both ends until I cut off the boots and let the grease out.
So, new link, and noise is still there. Stabilizer bar and bushings looked good, and I *think* the replacement shocks are OK -- they shouldn't have more than 25k-30k miles on them, probably less
I think I've read where dealers have put some kind of audio sensors on the suspension and are able to isolate the source of the noise. Is it worth it? I guess that's really up to me to answer, but I'm always reluctant to pay someone for something I can do myself. However, I'm running out of ideas to solve this problem, and I want a definitive answer before replacing the trailing control arms or anything else that runs into some real money.
check the 3 bolts on the upper shock mount, and maybe also the lower mount too? Just torque them down to spec. If you're really bored, you could always switch the shocks around and test drive to confirm its not them. It is a squeak and not a hum, correct? Just want to make sure it's not a wheel bearing or something. Sorry you're still dealing with it!
It is probably the infamous rear trailing arm bushings. There are a few threads on this causing a clunk. You cannot just replace the bushing, but must replace the entire trailing arm. However, now aftermarket parts are available for much less money than OEM. Mevotech makes them.
This is what I had. I had squeaks on both sides and a thump on one side when going over large bumps. They put some lubricant on the rear trailing arms and that stopped the squeaking. Then on the 2nd test drive they finally heard the bump and replaced one of them. That fixed it.
check the 3 bolts on the upper shock mount, and maybe also the lower mount too? Just torque them down to spec. If you're really bored, you could always switch the shocks around and test drive to confirm its not them. It is a squeak and not a hum, correct? Just want to make sure it's not a wheel bearing or something. Sorry you're still dealing with it!
-
I'd thought about replacing the shocks, but maybe taking another look at them (or swapping them) might give me some information. Thanks!
BTW it's neither a squeak or a hum -- it's a clunking/thumping/rattle in the rear quarter, somewhere in or above the wheel well.
This is what I had. I had squeaks on both sides and a thump on one side when going over large bumps. They put some lubricant on the rear trailing arms and that stopped the squeaking. Then on the 2nd test drive they finally heard the bump and replaced one of them. That fixed it.
Was it fixed under warranty or did you pay for it? And how much was it, if you don't mind my asking?
I think I can replace the trailing control arms if I need to -- it's looks like a little bit of a pain since I'd have to remove the brake caliper and rotor.
I can hear mine thump/rattle when going over small bumps, like when I drive down a slightly rough road or parking lot at 20-30 MPH.
03-03-19, 12:04 PM
Yet another “unidentified sound coming from the rear of the vehicle” thread…
