Rubbing Crunchy Noise From Front Wheels

[jvmitche]

Whenever my '99 RX (105K) is in motion and I execute a turn, no matter if it's sharp or soft, left or right, I hear this rhythmic rubbing crunchy noise from the front wheels.

It does not occur if I'm going straight ONLY when turning, left or right, soft or hard. The intensity of the sound does not seem to get worse/better with speed, it's fairly consistent. It seems to be coming from both wheels, but it could obviously be originating from one wheel -- as it's a little hard to tell. I've already been driving around the neighborhood with my head out the window too much as it is and unless my wife volunteers to be strapped to the hood I can't know for sure.

It almost sounds metallic, but it's definitely NOT a metallic screeching noise. It's more grindy and static-ky. I have to believe it has something to do with the wheels (and not a pump, etc) because it is rhythmic and the wheels are obviously spinning while in motion and the noise does not occur while stopped.

Any thoughts would be appreciated. I had the car Lexus dealer checked (when it was purchased) about 10,000 miles ago and again when I did the big 95K maintenace. At those times I was told the wheels, struts, CV, etc looked excellent for the age and I had about 15K left before it was time to replace the brakes. I've budgeted for a a full brake job late this summer, I'd just like to know what the heck this is and if it might even be dangerous (like a bearing). Thoughts?

[RX in NC]

My initial guess would be your wheel bearings but it could be a number of things. Have you upsized your tires lately?

[wwest]

Sorry, I don't have to guess, your CV joint(s) are due for replacement.

[RX in NC]

Yep, wwest is probably correct. I should have caught that as well since I remember losing a set of CV joints on a 1989 Acura Legend many years ago. When your rubber CV boots crack and split, most of your lubricant escapes and allows dirt and grime to enter and build up on the joints. The classic symptom is when you execute a hard turn or drive in a circle, and the metal-on-metal joints begin to make a rhythmic clacking or popping sound. That sound usually increases in intensity as you pick up speed while leaving your steering wheel cut hard to one side.

It's best to replace these as a set - left front and right front. This is a common job that's routinely performed by many independent shops, so check around thoroughly before you commit. Be aware that you'll come close to paying a Lexus dealership twice what a good front-end shop will charge you for the job.

[jvmitche]

I think what you're saying makes sense. I'm guessing winter kicked the crud outta those CV boots. However, shouldn't they make noise when the car is motionless too or manuvering slowly, say in a parking lot? Also, given the summer season is upon us, how long until serious damage is done to those CV joints? I'd venture the guess the sooner the boots are replaced the better for them....

[wwest]

The boots haven't necessarily failed, although that is a very distinct possibility. CV joints aren't under much "stress" when you moving straight.

It's the ball bearings inside the CV joint that are failing and making nthe noise when you turn. I woild have them checked right away as a sudden potential wheel lockup might result otherwise.

[RX in NC]

90% of the time when it's a CV joint problem, the rubber boots crack and split, your lubrication gets away, and metal-on-metal damage is done. You have to replace your CV joints as well as have new boots installed, so your problem isn't fixed by simply getting new boots. Sometimes the most cost-effective fix is simply to replace the entire assembly with a remanufactured axle. That's what most independent shops do these days for CV failures.

Get your vehicle checked out so you'll know what you're dealing with. Many chain shops will inspect your situation at no charge, including places like Midas Car Care. I'd start there and then do some calling around after you determine what the appropriate fix is.

[jvmitche]

Thanks for the info, I have a maintenance visit scheduled for this week. I will post back what the results were so anyone searching in the future will get some useful info...