Cracked brake rotor?

Custom_V6_Limited_SE · March 25th, 2006, 4:34 pm

I have had a problem ever since I got my car. This problem is that, when I make a very hard left going foward or backward, there is a grinding noise. Would anyone agree with me that this is, in fact, being caused by a cracked rotor? If so, would it be the left one or right one?

neutral · Post by **neutral** » March 25th, 2006, 4:58 pm

I'd first suspect a bearing going bad and second, a worn CV joint.

Custom_V6_Limited_SE · March 25th, 2006, 5:04 pm

It's not the CVs because those were replaced and it still did it. I don't think it's the wheel bearings because the wheels sound fine at all other times and the grinding sounds more like the brakes grinding than anything else.

lakersfan1 · Post by **lakersfan1** » March 25th, 2006, 5:14 pm

Try prying the heat shield away from the rotor some. My wife's 626 had the same sound on hard cornering. I suspected the heat shield on the brake rotor, and that's what it was. You don't havea cracked rotor.

neutral · Post by **neutral** » March 25th, 2006, 5:17 pm

Well you can pull the wheels and do a pretty quick ck of the rotors. With the car lifted, and wheels still on, you can do a prelim check for bearing wear by grabbing the tire at top and bottom and wiggle it to see if there is any play. Reason I said bearings is because, esp as one first starts to go bad, a rumbly or grinding noise is often apparent under only certain specific conditions. I'm replacing the front bearings on my '90 MX-6 and the pass-side bearing that went bad only made a racket when I made a fairly sharp left-hand turn under a certain acceleration force. Anyway, ck for wheel play if you're gonna raise the car to pull the wheels for a rotor inspection anyway. One other thing, a front bearing going bad will often also cause wheel chatter when applying the brakes. Can appear to be a warped rotor but is really the slop/play in the worn bearing. Ya doin't mention if your rotors are cross drilled. I'd be surprised to find one cracked if they're not x-drilled but s'pose anything is possible. g/l

Vanished · Post by **Vanished** » March 25th, 2006, 5:25 pm

does the grinding slows down when the car slows down or speed up when the car speeds up? If its a cracked it woudln't make a steady griding sound....it woudl be more of a beat, like "shrp...shrp...shrp..." if its a "srgrrgrgrgrgrgrrrrgrrgrrrrrrrp" then its most likely your CV join. Also, does it grind when you have the wheel turned as far as it goes, or just a couple rotations?

Custom_V6_Limited_SE · March 25th, 2006, 10:15 pm

I guess the heat shield is starting to sound more plausible than a cracked rotor. They aren't cross drilled. It is a constant grinding that sounds "faster" the faster I go. I'll jack it up and bend back the heat shields. By the way, How important are the heat shields? Would it be bad to completely remove them?

Custom_V6_Limited_SE · March 25th, 2006, 10:50 pm

OK, I just jacked it up and bent back the heat shields; however, it is still making the grinding sound. Either I didn't do enough to the heat shields or maybe it is, in fact, my front right wheel bearings (that's where the noise is coming from). So, my next question is how much does a wheel bearing run?

Cy · Post by Cy » March 25th, 2006, 11:55 pm

Custom_V6_Limited_SE wrote:OK, I just jacked it up and bent back the heat shields; however, it is still making the grinding sound. Either I didn't do enough to the heat shields or maybe it is, in fact, my front right wheel bearings (that's where the noise is coming from). So, my next question is how much does a wheel bearing run?

i cut off my heat shields.. there restricting airflow around the disc.. that's worst then warming up your lower ball joint..(although it might melt the ball joint boot if you get them red hot)...

neutral · Post by **neutral** » March 26th, 2006, 8:39 am

Custom_V6_Limited_SE wrote:OK, I just jacked it up and bent back the heat shields; however, it is still making the grinding sound. Either I didn't do enough to the heat shields or maybe it is, in fact, my front right wheel bearings (that's where the noise is coming from). So, my next question is how much does a wheel bearing run?

Didja see any play when you shook the wheel? Anyway, for parts, replacement bearings run ~$35 USD each. Not absolutely necessary to replace both front ones if only one is bad but usually a good idea to replace the pair since they have been wearing together. In my area, (Maryland) total cost for a shop repair of both bearings is ~$400-450USD. Mostly labor cost and includes having the old ones hydraulically pressed out and new ones pressed in. DIY cost, if you have the tools already, is ~$100USD and that includes having a machine shop press out the old and press in the new bearings. Remember, some auto parts chains have tool loaner programs that cost you nothing to borrow while they hold your deposit - returned when you bring back their tools. If you want to know more about parts sources and what you'd face for a DIY repair, ck this thread and the online manual. Can be a PITA but worth the effort IMO to save the bucks, + you'll get an up-close look at the condition of the rest of the front suspension components and feel good to have done the job yourself.

http://www.mx-3.com/phpbb2/viewtopic.ph ... 8dba7dad5c

Custom_V6_Limited_SE · March 26th, 2006, 6:58 pm

There wasn't any play in the wheels in any direction (except for spinning of course).