Clutch - Flywheel vibrations
 

I have just under 10K on my RX-8 and I believe that something is wrong with my clutch or flywheel or some other part in that vicinity. Here is basically what is going on.

Starting from about 3,000 miles on my car, I began to feel a slight vibration on the clutch pedal, just before engagement. This would occur no matter if I precisely rev-matched or released the clutch in the general vicinity of the new RPMs. Now this would happen maybe once every two weeks or so for the duration of the trip. After the car was restarted a few hours later, the vibrations would go away. I just assumed some parts were wearing in or something like that.

Now with just under 10K miles on my car, this vibration is always there. Now, I have to admit that I did take the car to the track for 3 days just before this happened and put about 250 track miles on it. Very intense driving, but I believe I was pretty good on the clutch (always letting the RPM drop naturally and heel-toeing). I did not sense a problem on the track, but on the following day, the vibration came back and has not left. I did mess up once on the track by dropping the car in 2nd gear instead of 4th going 85 MPH. But I would not expect this to screw with the clutch.

I can always induce the vibration by barely (and I mean barely), pushing down on the clutch pedal while cruising. In all situations, the vibration is very very slight. There is no car shaking or noise. This occurs for all gears. I can only feel it through the clutch pedal. The car still accelerates as normal and I have no problem driving hard at high RPMs. The only thing that I could observe is that it seems that the car is more forgiving when I start releasing the clutch at slightly incorrect RPMs. Before the car would jerk a bit, but now, the transmission syncs up with the engine more smoothly. But I think that this is more due to me being more smooth on my shifts.

Can anyone please tell me if they have/had similar experiences or if they have some idea of what might be going on? If my clutch is starting to go bad, are there some test I can perform?

wouldn't a bad clutch make the gear shifts more grabby/ quick to engage? what you're describing doesn't sound like its so much a bad clutch as just a quirk. I've felt some minor vibrations through the clutch pedal from time to time but the car still shifts fine and there's no other signs of issues other than the supposedly normal noisy transmission in these cars. So i wouldn't borrow trouble if I was you.

The pressure plate has come loose or has gone bad.

when you say, "pressure plate has come loose or has gone bad," do you mean that its not letting the clutch off of the flywheel? Or that its not pushing the clutch hard enough against the flywheel?

I will get that date a little later tonight. But after doing some online research I guess my symptoms would most closely resemble: "PEDAL PULSATION," as described on the following page: http://www.fanshawec.on.ca/disabilit.../chapter33.htm. But the pulsation is so rapid, that its more like a mild vibration.

It's called "Clutch Shudder". It's a common problem with clutches some more likely than others (extremely common on the Mazda6). If you had made a complaint before and got it noted in your service file you might be alright, but at 10K miles Mazda is very likely to claim it's "Abuse" and not cover it. Take it up with the dealer immediately and be prepared to take it to your regional manager.

Even if I did abuse it, isn't the clutch assembly under a 12 month warrenty? "Abuse" is such a vague term, especially when mazda endorses track days and has the folllowing quotes on their website:

"Such is the smoothness that Mazda has provided an audible "beep" when redline is reached to remind you to shift. Listen for it, as it is easy to reach redline sooner than you expect."

The clutch is under a 12000 mile warranty, yes, but not if its' abused. Abuse isn't covered period. And, yeah, it's vague that makes it harder for you to make their case. Your argument is that "there's no way a clutch should go in 12000 miles", Mazda's argument will be that "the only way a clutch could go in 12000 miles is if it was abused". Most dealers will anyhow.

is clutch shudder actually bad for the transmission, or is it one of those quirks that won't cause major problems.

Hop on it now man. The dealer will be able to tell if the clutch was "abused" or not when the tranny is dropped. I had an issue with one of the clutch hub rivets breaking and releasing a hub spring. It was right at the limits of warranty, but the dealer went to bat for me stating to Mazda that the clutch looked almost brand new with not hot spots and/or signs of any abuse. The thing just broke. It happens. I'm thrilled with the dealer (jim ellis- Atlanta) and the extra steps they went to for me. Most Mazda service centers go out of their way to help the 8 folks (most really, really like the car). Just get it taken care of soon.

Well, I took it in and they said it was nothing to worry about. They didn't take anything apart. They simply checked some hoses and drove it around a bit. At least now its on record that I complained. Hopefully this trully is nothing.