Rattle from rear wheels
 

Hey All,

Did some searching on this one and couldn't come up with anything. Any time I hit a sharp bump (with windows down) I can hear a "metal-on-metal" rattling sound coming from my rear wheel area. However, when I apply the brakes and hit sharp bumps (i.e. raised reflectors), there is no rattling sound. I removed the rear wheel and took a look around and banged on different areas to try and reproduce the rattle but to no avail.

Because the rattle is absent under braking, I assume it's somehow related to a component of the brake system.

After searching google, I read a thread stating that rattling was occurring from where the parking brake hooks near the caliper. Upon checking mine, there was indeed a little play. I didn't see a way to adjust how much slack there was down there, so I adjusted the parking brake from the console inside the car. However, after tightening the parking brake down, the rattle still remains.

Is it possible that adjusting the parking brake from the interior console wouldn't take the slack out near the rear calipers?

I'm running out of ideas on what could be the cause of this rattle. Any additional input would be much appreciated!

How much pad do you have left in the rear? Are the clips and shims in them? If not, it might just be the pads rattling in the caliper.

i agree with Fuztupnz... ive seen brake pads causing a knocking rattle noise over bumps. check to see if you can easily move them fore and aft. if so replace the pads and hardware.

Check ur TPMS sensors, jack the wheels up and roll the rear tires with ur hands. LOL. Mine came off at the left rear side and made nasty glass/metal like rattling

Thanks for the responses.

The pads/rotors were replaced about 3,000 miles ago. Plenty of life left in pads. I'll check to see if they're loose.

Lol, I did check to see if the wheels were the source of the sound. Took the wheel off and bounced it up and down with no sounds =)

i have the same exact problem. but i only hear it when the car is warming up. after about 5mins of driving is disappears. i haven't investigated the source of the sound yet, but if you happen to find it, please let me know what was making noise in your car and hopefully it's the same in mine.

I have that rotational "clunk" on my front left wheel when I replaced my pads, it clunks as the car is driven and disappears once the brakes are applied, I'll have the rotors replaced or resurfaced on my next pad change.

does the wheel shake when you brake? if so, rotors are warped.... yes it can happen, i work for a brake shop and it happens more often than not and esp with brake happy vehicles

If it is brakes, you need to use Goop silicone on the back of the pads.

A nosie can come from anywhere. Loose heat shield or muffler clamp, anything.

I suggest riding in the trunk with a friend driving the car.

Take an auto shop class.

Ask your dad for help.

Yep... not entirely the wheel nor the car, but I could feel the brake pedal slightly wobble as my car approaches to a slow stop.

The clutch pedal wobbles as you are stopping the car? ?

That's the vracket.

What the hell are doing looking at your feet when you stopping the car?

This is a long shot, but do you have the optional spare tire kit? I had a rattle from that area. Turned out the bolt holding up the spare wasn't fully tightened.

Thanks for the input. No spare tire kit. Here's what I found searching on Google:

http://www.2carpros.com/forum/2006-m...-vt460830.html

A "anit-rattle clip" that could have been installed incorrectly or not at all?

The dealership installed my rear brakes so I'm going to take it to them to fix. Of course I'll push for no charge =)

I'll update everyone on the findings.

I found out what's wrong with mine, it's not the bracket; there are two rods that bolts on to secure the caliper, the upper rod is completely loose. I have to rebuild it as it appears that the rubber boot came off and dust/dirt dried out the grease inside.

Wow, good find. I'll double check mine to make sure I'm not having the same problem.

I took a look at my rear brakes to replace the pads, it's rear brackets are not equipped with rods as the fronts do.

your brake pad kit should have come with grease. Those bolts if I think its the ones your talking bout allow the caliper to freely flow on the bracket. If thats the one that came out I would suggest you use brake cleaner to get it incredibly clean. Properly re-grease them, and since your going to have the caliper apart already I would remove all of your clips. Steel wool them and parts cleaner them clean. Make the clips look brand new if your going to be taking it apart anyways.

UPDATE:

When the delaer (Long Beach Mazda) replaced my rear brake + rotors, they did not install a shim kit which has been causing the rattle. When I inquired why a shim kit was not installed, they said that on the RX8, shims were not standard with the brake pads. To get the shims, I would have to pay for parts ($48 for both rear shims) but they would waive labor fees for the inconvenience of the extra trips I had to make to the dealer.

A little confused, I thought shims were always standard with brake pads, at least on OEM pads. I called Mazda North America and told them about my situation and told them it didn't seem right for me to pay for the shims, because I was under the impression that I had paid for them already when I got the brake pads replaced.

After a couple of days, I returned to the dealership and they informed me that Mazda North America had contacted them and they'd be willing to give me half price on the shims. I'm satisfied with the results.

Interesting note. Mazda Long Beach is a independent dealership and the Mazda North America Rep told me they had little influence on over the dealership.

Is that the one near the Airport, on Cherry Ave and E Wardlow Road? I was just there today to buy OEM Plugs from a guy named "Jim". BTW, I'll go ahead and tackle the front-left brake caliper since I'm replacing the plugs at the same time.

I have always just cleaned mine up and put them back since hawk doesn't send you clips. But thats the parts I was telling you about checking, the clips/shim go in the caliper bracket and on the back of the pad.

Yeap, that's the one! Cool, I was chilling chilling in the lounge from ~0930 - 1200.