Intermittent noise from front wheel

[Stanley]

Made a right turn, slowed down, went over a bump in the parking lot, and after about 50 feet a fairly loud, metallic ta-ta-ta-ta-ta noise started coming from the left front wheel (or maybe suspension). Was going slow and opened the door so I'm sure it's left front. The noise continued until I parked. Jacked it up and spun the wheel both ways - nothing. Didn't see anything wrong under the car. Took a short drive, all ok and couldn't repeat the noise.

 

About two months ago I had the front and rear brakes done (front left was grinding) by a shop that has done good work for me before. (I'd done the front brakes myself about 15000 miles ago with new rotors and calipers from MSA.) They put new pads (whatever the parts store had) and machined the rotors. Everything ok. 

 

Two weeks ago, after hearing some occasional noises under the car I took it to the shop to lube it and check; they replaced control arm bushings that looked bad.

 

No time to work on the car until next week, wondering what to look for when I take the wheel off.

[siteunseen]

Hopefully it's loose pads, cheap loose pads.  That spring like thing that goes under the pins could've come loose?

 

[jfa.series1]

Check your wheel bearings also.

[siteunseen]

Check your wheel bearings also.

That's a good point, Jim.  I replaced my front bearings and didn't torque the big nut down to spec, which is very little, I just tightened it until the rotor was solid and spun freely.  After a couple of trips I heard a bumping noise, took the wheels off and sure enough the rotors were wobbly.  Torqued them down then, lesson learned for future brake jobs.  Another instance I used the FSM for specs. 

[Stanley]

It was the wheel bearings. When I did my front brakes in 2008, I replaced the outer bearings, but just greased the inners, since it seemed like too much work. So they were toast. Glad I didn't try to do it myself. All better now.

[siteunseen]

Good deal.  Getting the race in there was a little tricky without a press.  

[Stanley]

It's not fixed. After not driving a few days (out of town) took a trip for groceries, same ratcheting sound occurred briefly, didn't repeat. Shot wheel bearings were coincidence. If not brakes or wheel bearings then what?  

[bartsscooterservice]

Good chance it's the wheel bearings, but to be sure you have to check it

[rossiz]

[Stanley]

Yes, card on the wheel is the sound.

[Zed Head]

Is the frequency of the sound a clue?  There are some things that would have a consistent frequency; the four bolts to the hub, the four scallops if you have an early 240Z, four lug nuts, spokes on a mag wheel, the ribs on a vented rotor, etc  Don't even know what kind of wheels you have or how fast you were going so it's hard to guess.

 

Also, no offense, but how did the brakes start grinding after just 15,000 miles and what was grinding?  Might be a clue.

 

I found that one of my rotors had the inner dust shield (the actual formed in and machined ridge on the rotor) completely worn off from a pebble or some hard object that had been stuck there.  Either that or the PO had ground it off for some reason.  Must have made some noise.

[Zed Head]

One more thing - people have just posted recently about having their bearing seats wallowed out.  If that happens the bearings will still be loose even after you follow the factory torque and loosen procedure.  Try grabbing the top of the wheel with the car on the ground and shaking back and forth.  If they're loose you'll hear it at the bearing.  I have a worn one and my new procedure is to tighten until the shake test sounds right.  The Nissan procedure doesn't work anymore.