Supermoto65

So I installed a new Supermiata sprung puck sport clutch, lightweight flywheel and a new clutch slave cylinder on my NB. I have an MKTurbo kit with a mild tune so I am sure it's not overpowering the clutch. Worked well for 200 or so miles ( I don't drive the car a lot). Drove it a little harder and was fine.

Decided to teach my 14 year old Son how to drive a stick ... he was actually the one that got me interested in Miatas but anyways. Most of the time he was letting the clutch out too quickly and stalling or lurching the car a lot. Might have slipped it a few times but not badly. Probably 50 or so attempts in total. Yes, he did finally get it and was stoked to drive the car!

Now I have two issues:

1. A slight whirring noise when idling that goes away as soon as clutch pedal is depressed. Maybe pilot or throwout bearing? They were replaced with kit from SM.
2. More worrying - Sometimes a chattering or low squealing noise as I let the pedal out on 1st gear starts. No noticeable vibration. Hard to describe and it doesn't happen all the time .. maybe 30%. Doesn't matter if I am being aggressive off the line or just casual.

Any ideas? Did I make a big mistake letting him abuse the clutch that way? Not looking forward to pulling the trans again but I guess I will probably have to?

x_25

Both of those symptoms say bearing to me.

HarryB

+1 on the bearing diagnosis. The squeal may go away if you lube the slave cylinder rod.

tehzack

I've had a spec stage 2+, factory replacement exedy from Mazda, and now run a 949 sprung 4 puck.

Both the spec and the 949 occasionally squeal like you mention when taking off. Both chatter to some degree.

On EVERY clutch iteration i've had in the car, after a few hundred miles the TOB starts squealing lightly at idle until the clutch pedal is depressed. I've probably put 5 or 6 throw out bearings (sourced from Mazda, 949, and Rock Auto at different iterations) in the car over the years with both 5 and 6 speed transmissions and they all squeal. I've just come to accept that I'm inherently flawed at tob installation, it will always be this way, and there is no victory to be had in this department.

I'd say you're fine. Just keep driving it.

Supermoto65

Yeah .. I get some chatter off the line depending on how lazy I am on the clutch but the squeal only started after the lessons. I'll try a little lube on the slave cylinder ... don't remember if I did that on install. Then just gonna send it!
Thanks for the replies!

curly

iTrader: (25)

Once the throw out bearing gets hot, it looses a lot of it's grease, and you can be left with a chirping bearing as it barely sits on the clutch fingers. You could try adjusting the clutch, the most important thing is to not drive around with your foot on the clutch pedal what so ever.

FM has a heavy duty TOB for their FM2 clutch, I'm not sure if it's available separately however.

msmola2002

They used to, because I bought one last year. Catalogue number on my purchase was W08-16912, listed as HEAVY DUTY CLUTCH RELEASE BEARING, NA/NB and was 79.99 but searching that number and those key words brings up no hits when I search the website.

Looks like it is hidden in the level 2 bearing kit, new pilot, install tool and HD TOB
https://www.flyinmiata.com/clutch-ac...r-level-2.html

codrus

Call them and ask?

AIUI, when new and inexperienced drivers damage clutches they generally do it by slipping them for too long, with too much power going through them and they overheat things. Too little slippage just stalls the car and is not likely to damage the clutch.

--ian

Bronson M

iTrader: (1)

My SM puck clutch will squawk off the line under certain conditions. I've heard ACT and spec pucks do the same thing, just the nature of the beast.

Supermoto65

Yeah ... I keep my foot off the clutch pedal while driving.

That's what I thought as well. We will see. Not gonna worry about it. Thanks again to all for the replies.

turbofan

iTrader: (1)

To echo the others, an occasional noise or chatter is normal from a puck clutch.

I'd just monitor it and see if any of the noises get worse.

Joe Perez

iTrader: (8)

To echo Turbofan, yes, puck clutches make noise.

And I'll also chime in that both of my last two Miatas (both with OEM-style release bearings) also make the slight whining noise at idle untill the clutch is depressed. (I assume that they also make this noise when in gear, but it gets drowned out.) I fretted about it for quite a while, before realizing that my clutch wasn't explosively failing as a consequence of it.