tfbmiata

I know i've become a frequent poster here (sorry, newb to both working on my own car and track days). I bought an '02 6 speed LS about 3 months ago and have done 4 track days. After my first track day, I deduced the throwout bearing was dead and had a clutch job done $900 plus clutch equipment (OEM replacement). It was the correct deduction as the car wouldn't go into gear and screamed when pressing in the clutch pedal.

After my fourth track day, I've returned home and now upon starting the car and driving out of the driveway, I'm getting that telltale scream again. This time it doesn't seem 100% exactly the same, but it seems close. Sometimes when I'm highway driving, it seems to squeal a bit going from 4th to 5th, etc. The thing is, after my first track day, that being bad almost made sense as the squealing happened before the track day happened and the guy that I bought it from said he never did a clutch job, just the gear oil. That first track day, while i tried, I was doing a terrible job at rev matching, I'd give myself a 2 out of 10. However, I've gotten a TON better at that since and in the follow up track days, I'd rate myself at least a 6 or 7 out of 10 on it.

So, onto my questions. Are miata just throwout bearing killers? Am I rev matching wrong and that is causing it? Could not rev matching properly even cause throwout bearing death (obviously within reason of not doing crazy ****). I can't afford a $900 clutch job every 3 to 4 track days and I'm honestly now considering selling the car, but I can't imagine this is right. Could this be something else entirely I haven't thought of? The guy who had it before me said he did all the belts less than a year ago and they all look new.

One last thing to throw some confusion into the mix. At my last track day, the shifter got SUPER sloppy. After the track day, I pulled everything ready for a shifter rebuild, and noticed the turret housing was missing one bolt and the other 3 wear all loose. Not crazy loose, but enough that moving the shifter moved that top plate around and added to the slop. When getting under the car later to added some heat shielding (my *** is on fire from the cat being so close to the floor pan drop), I noticed everything seemed to be covered in a thin layer of oil. Best I could tell it was gear oil and not motor oil, but I'm not expert. I've of course cleared all that up as much as I could and did a shifter rebuild kit (omg, heaven), but I'm concerned that the gear oil is low in the trans and could that have also contributed to what seems like a possible throw out bearing issue?

Thanks everyone for the continued help. (If you are a miata.net forum member, sorry for cross posting, but weirdly they seem to lack a lot of response sometimes.)

joe morreale

In my opinion, you should start by draining your trans and filling it with a quality synthetic gl4 lube. Dont remove the plug from the passenger side of the trans! Put 2 quarts in through the turrent.
You say the clutch replacement kit was oem. Do you know what brand it actually is? Most on this forum have upgraded clutches, typically ACT or FM. I have heard of TO bearings not being greased properly, causing issues. If this is the case I would avoid the shop that charged you $900. Does this shop service miatas routinely? With a lift and air tools, I wouldn't think that its more than a 3 hour job. Just to question their competency, did they surface the flywheel? Sorry I can't answer your question, but I wish you luck. Keep posted with your results.

rascal

not in my experience.
My NB1 track car has just had a new clutch so new throwout bearing with that after 12years and 117 track days including the last 20 with F/I (240hp rotrex)

Unrelated. The throwout bearing lives in the (usually dry) bell housing, not in the gearbox internals with the oil so oil level is irrelevant.

tfbmiata

Yea so, it took them like 6 days. I brought them a new flywheel as well. I believe it was all "Exedy" which I'm sure is Chinese for cheap as ****, but I thought I had used them in the past when I was but a kid on a b16 civic I had and it worked out super well (though I didn't track it).


Thanks. I thought I had read that as far as them being separate, but couldn't find anything on it. This gives me hope!

tfbmiata

To finalize this topic, the grinding part of a bad throwout bearing never happened. My guess is that the scream is either oil getting on the belts or the ac compressor going bad.

curly

iTrader: (25)

Exedy is great for OE replacement clutches, fyi.

If you're resting your foot on the clutch pedal, even if you don't think you're pressing on it, you're pushing the throwout bearing on against the pressure plate springs. This causes the bearing to spin at engine RPMs constantly, it should only do this when you're shifting, and otherwise sit still. Ridding the clutch pedal wears out throw out bearings drastically faster. You can also adjust them to have too much preload, but it sounds like the previous owner didn't touch the car much, so unless you did, I wouldn't expect clutch adjustment to be the issue.

emilio700

iTrader: (3)

Release bearing is designed for intermittent use, as when engaging/disengaging clutch. If the driver either rests foot on pedal or there is no freeplay in pushrod, the bearing can quickly burn up.
A quality bearing will last many years. It should always be replaced when any clutch service is performed.

When in doubt, set clutch pedal according to OEM service manual. The exception would be any clutch that has proprietary pedal adjustment specs.