I've been trying to figure out this clicking noise from the front, driver side. This is a 2011 RX 450H AWD with 112,000 miles. This noise has been present for a while.I replaced the struts, regreased the inner CV boot on the driver side, checked engine mounts. The noise occurs when car starts moving (in gear) or when I brake at low speeds (maybe I'm not hearing the noise at high speeds). It's not the brakes - if I shift to Neutral there is no clicking whether I brake or the car starts moving. In the video car is moving electrically, so the clicking is easier to hear, and it occurs twice at ~ 4sec and ~7 sec.

 

Had this issue, it was an axle nut that needed replacing.

 

Can you be more specific? I looked at several bolts/nuts around the suspension and didn't find anything loose :-(

 

I think he means that after you remove the wheel, there is a large nut in the center which is the axle nut. Look up the torque, get the proper torque wrench and check if it will get any tighter.
Do you have a torque wrench (250 pounds or more) or a socket large enough for the axle nut. The axle nut torque is 217 pounds.

I doubt that is your problem. These strange noises can be frustrating to diagnose and your best bet may be a good independent repair shop. This chassis is used in so many Toyota and Lexus vehicles (and has been for almost 20 years) that every shop is familiar with the mechanics. Use Google and Yelp to find some good shops nearby.

 

I appreciate your input. I also think that's not the culprit - that nut is locked in place, I would have to replace it rather than just tighten it. I'm starting to lean towards replacing the CV axle. I'm not very familiar with how the gears and the CV axle work together but since while in Neutral there's no clicking although the CV axle is spinning, and the clicking comes up only in gear when the CV axle is engaged with the transmission (thus under pressure) there must be something wrong with the bearings inside the boots ?! On the other hand the clicking sounds "external" - if it was coming from inside the boots it would have been more of a muffled clanking.

 

You said you re-greased the driver side inner CV boot. Why did it need grease? Usually that is only needed when the boot rips. What is the condition of the other boots? How are the ball joint and tie rod boots?

Have you inspected each brake caliper and all brake components such as the dust shields (they get bent) and that the caliper slide pins are greased and moving freely? That there is enough brake pad left for safety?

Have you changed the Hybrid Power Transfer Unit (a/k/a transmission) fluid? It is an easy 4 quarts drain and fill of Toyota WS or Idemitsu TLS LV ATF.

 

I re-greased the driver side inner CV boot because I noticed some grease splattered around that area; the boot was not compromised - I think grease was escaping at the boot end (maybe loose clamp); so I re-greased it and installed new clamps. All boots look intact.
I have not taken the brakes apart - I inspected them visually and manually (i.e. nothing is loose). I eliminated the brakes as a possible culprit because there's no clicking whatsoever when I'm in Neutral, no matter how I brake.
I have not changed the transmission fluid - the transmission shifts perfectly and I have great acceleration.
I lifted the front end and there is some play when I start turning the wheels - maybe that's normal. When the car starts moving (in gear) from a complete stop it's not a swift, tight start - I hear something "engaging" before the car starts moving.

 

The axle nut is behind the wheel cap, it may appear correctly torqued but they can slip. Its a very quick job, Lexus did it for free. I visited a series of garages before going to Lexus and they had no idea what I was talking about, I would take it to Lexus and ask them to check it. With mine there was no click in neutral but clicking when in gear accelerating and braking. Apparently this is a common issue with this model.

 

Hopefully you will soon figure out the source of the clicking noise, and I saw you also posted on the hybrid forum which provided a lot more responses than this side.

Regarding the power transfer unit, it is not a normal transmission, it has no gears, and is not a CVT, you can change the fluid anytime with no danger and it is recommended you do so every 50,000 miles. There is a very expensive pump inside that benefits from clean fluid. This fluid change is as simple as changing your engine oil. See this thread from the hybrid forum for more information.

https://www.clublexus.com/forums/hyb...nd-rear-2.html

 

I really appreciate all the input and suggestions. I will take a closer look at the axle nut first.

 

Let us know how it goes.

 

Lo and behold, it was indeed the axle nut. I had to purchase the right deep socket and a new OEM axle nut. After I put on the new nut I wasn't able to torque it properly because I wasn't able to get perpendicular leverage and I was afraid I might break something - I got it as tight as I could without overdoing it. (I did not lock the nut in place.) I drove around my neighborhood and the clicking noise was 80% gone. I went back and used an extender with the torque wrench, I pressed it perpendicular on the end of the axle and was able to get the torque wrench to click (at 217 ft/pound). I drove around the neighborhood again, no clicking, I then locked the axle nut in place and later drove on the highway - so far no more clicking whatsoever. So it appears that proper torque is critical! Thank you all who helped me diagnose this clicking noise!!!

 

Excellent news!

 

Well done.

 

@DracuGol , didnt you have to remove the axle to replace the cv boot clamp and regrease that cv joint? Or did you use an aftermarket universal kit for that? The OEM cv boot clamps don't open up iirc. Trying to figure how the axle nut loosened...I don't recall reading that these axle nuts back out by themselves.