PAIRdoc

Happy Thanksgiving all.

I have a 2009 RX 350 with about 75K miles on it. Last Saturday, I changed the rear brake pads and rotors without any problems. The pads were at 4/32 and I added a bit of brake fluid to the master cylinder to bring the level to the proper height. I also put my Blizzak tires on for the season (pre-mounted on rims) and changed the oil.

Yesterday, while on a road trip, I noticed a faint, rhythmic knocking sound coming from what sounds like the driver side front wheel. Over the ensuing 150 miles, it appears to be a bit louder and more noticeable. The noise is best described as a knocking or clunking sound, and seems to correlate with the rotation of the wheel. That is, the tempo of the sound increases as the vehicle speed increases. I also notice that the sound is most dramatic when I turn the steering wheel towards the left, even just a tad; the noise lessens (or maybe disappears) when I turn the wheel away from the left (i.e., straight or towards the right). The noise also seems to disappear when I apply the brakes, even just a bit. I have no brake judder at all.

The tires are in great shape as are the front brake pads and rotors (changed about 6 months ago), though I didn't take the wheel off to see everything clearly. I visually inspected the CV joint boots of all wheels and I see no cracks or leaks. I'm not sure if this is something related to the brakes, CV joints, axle, bearings, steering linkage, or suspension.

I am very concerned about this noise, especially about safety. Everything is closed today for Thanksgiving, and I have to work tomorrow. I have an appt with Lexus on Sat morning for routine inspection, and I am hoping that I can drive the car to/from work tomorrow without any problems and without exacerbating the issue (about 80 mile round trip).

Any input from those on this site who might have an idea what this problem is would be greatly appreciated.

Thanks!

alchemist

iTrader: (1)

This sounds like bearing to me but normally they squeak and then grind when you turn the wheel.

Any noise or clunks over bumps?

Does your car drift or pull while at highway speeds

shikbas

Did you check the new brakes on the rear? It happened to me before that the hardware was loose/bad.

HtownBlue

Jack up wheel and rotate tire. If you can jack up entire front of car where both front wheels can spin freely and rotate and listen for sound. Try to see if noise goes away in neutral. See if noise is only on acceleration.

jfelbab

Sure it's not a tire issue? I'd try putting the regular tires back on and see if the noise is still present. If so, maybe its a wheel bearing problem? If it points to the tire(s) it could be a belt separation or flat spot. How were the snows stored?

PAIRdoc

Thanks for all of the responses. Sorry for my delay, but I've had my hands a bit full.

I finally figured out what the issue was, which I'll explain as I finish the rest of the story I started above.

Let me first say that while I change my wheels for snow tires once a year around Thanksgiving and change them back again around Easter by myself, I have never changed brakes myself, so I had an experienced friend do it while I assisted so I could learn the process. At the same time we changed the rear brakes, we changed all 4 tires for the winter ones. My friend is quite knowledgeable, and has a fairly well-equipped home garage, and does this stuff quite regularly.

After I returned from my trip on Thursday morning, I told my wife about the noise and asked if she could help me identify the wheel it was coming from (I was pretty sure it was the driver front). Of course, she was getting ready for Thanksgiving (we were going to her cousin's), so she couldn't (or wouldn't). MIssed opportunity #1. I was going to jack up the car and check things out myself, but found I could see pretty well upside down on the ground, and didn't see anything wrong, including the axle boots. Missed opportunity #2. I called my friend and explained the noise to him, and he was puzzled, too, and thought it might be the CV joint. Missed opportunity #3. I called every gas station and Midas, etc. within 5 miles, and of course, none was open. Missed opportunity #4. My wife wanted to take her car to her cousin's, but I convinced her to take mine, since the noise wasn't that bad, and I wanted her to hear it for herself. I also told her I drove over 150 miles earlier in the day without any issue but the noise. This turned out to be a lucky break for me, as you'll read later.

So, we loaded our car with food my wife cooked, and drove to her cousin's about 5 miles away. She heard the noise, and thought it sounded very abnormal (so did I, since it was a bit worse). I showed her how breaking a bit stopped it, though, and thought it was something with the brakes, perhaps. At my cousin's, I explained to one of my relatives who does custom motorcycle and some car restorations about it and he said it could be loose lug nuts, which I dismissed, since a pneumatic wrench was used to remove and retighten them, the CV joint, or a wheel bearing. I told him I was going to have it looked at on Saturday. I could have asked him to look and listen with me, but didn't, since it was cold and dark out. Missed opportunity #5.

After dinner, around 7:30pm, my wife and I drove back home. Halfway back, the noise suddenly got much worse, with significant knocking and vibration of the car, this time whether the wheel was turned left OR right. But still, it stopped when I gently applied the brake. My wife thought I had a flat. I stopped the car in a store parking lot and inspected all wheels and tires. Everything looked OK. All lug nuts were on and nothing looked suspicious.

We decided to drive the remaining 2 miles to our house, and the vibration was even worse as we turned left onto the street entering our development. I would have stopped again, but we were literally about 100 feet from our driveway and thought we'd just get it there. Unfortunately, on the last left turn in the development leading to our house, the problem manifest itself in its entirety while driving only about 5-7 mph. The left front wheel came off and rolled about 12 feet until it hit the opposite curb while the car slid on the front rotor about 10 feet. The car was now stopped and we were both in shock. I tried to open my door and couldn't and exited via the passenger door. I inspected the damage and saw that three studs were snapped off completely with only two remaining. I found one lug nut five feet back and the threads were badly stripped. I also noted the in the process of coming off, the tire must have hit the rear part of the tire well, causing moderate buckling of the fender, which was preventing my door from opening.

Apparently, I neglected to consider the obvious here - that the lug nuts were insufficiently tightened. Whenever I have changed my tires over the past 2 1/2 years, I have always used a torque wrench to ensure that I was tightening properly (not too much and not too little) and never had an issue. My friend used a pneumatic wrench, which has 4 settings, and he told me he always used setting #3. We actually tested one of the lug nuts by securing it with his wrench and then using my torque wrench to see how many ft-lbs it required to loosen it, and it seemed good at about 80 ft-lbs, so I was satisfied. I didn't check any others after that. Missed opportunity #6. When I inspected the car when at home and when we stopped on the way home from my cousins, I noted that all lug nuts were present, but didn't check to see if they were loose. Missed opportunity #7.

I called AAA, who towed the car to my dealer's lot (couldn't leave it in the street and didn't know where else to tow it). I called my insurance company to file a claim, but, of course the call center told my they wouldn't be back until Monday due to the holiday.

I tried to get a rental car the next day (Friday), but all local rental offices were closed, too. On Friday, the dealer told me that they would need to have it towed to their collision center for repairs, and I was told it would be 2-3 weeks due to their backlog.

I rented a car on Monday (today) and spoke with the insurance company, who told me that my claim will likely not be covered, as it was not a collision, but rather a mechanical failure, and that the policy excludes these.

So now, I am out the cost of whatever this repair will be, plus the cost of a rental car for a few weeks, and feel like I was so close to possibly picking this up before this disaster occurred. I feel like the biggest moron around, and am only posting this because (1) I need to vent a bit, (2) I'm looking for consolation from anyone willing to give it, and most importantly, (3) to let everyone learn from my experience that it won't ever happen to them or someone they know.

The only silver lining here is this. If I did not insist on taking my car to my cousin's on Thursday night, I would have taken in the next morning to work, which means driving at about 75-80 mph (yes, I know it's speeding) on the PA turnpike, where the wheel would most certainly have come off. G-d only knows what the outcome could have been. So, my wife and I are counting our blessings that nobody was physically injured, and hopefully all will be back to where it was in a few weeks (less a few thousand bucks, I estimate).

Anyhow, that's my story, and I will proudly accept the Idiot of the Year Award for 2013.

Thanks for listening and for your feedback.

P.S. We did have a nice Thanksgiving meal.

tkoband

You just saved me!!!! Heard the same noise, how it stopped with brake application , how it was getting worse over the past few days!

Checked my lug nuts and sure enough! One was loose!

I hope nothing else was screwed up by the delay (about a week) in fixing the problem.

And by hoping nothing else else us screwed up I mean I hope the stress on the other lug bolts doesnt cause them to snap off any time soon!

kcknebel

I've done this, too! Check and recheck those lug nuts with a torque wrench, if possible.