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View Full Version : Miata experts, chime in. Possible clutch issue



SajBT36
10-31-2011, 04:27 PM
Hey folks,

Just charting up my winter 'to-do' list on the Miata and one of the areas that is looking a little suspect at the moment is the clutch.

I got about 4 autocrosses in with it this year. At the second event I had a codriver, on a hot day when the clutch started slipping pretty bad at launch. Would be fine if we did granny starts though.

I figured "Meh, well, clutch is on it's way out", but when road driving, I tested it out but pressing the clutch at 60 kph, uphill, in 5th, revving it up and releasing sharply. It took it like a champ, no slip at all.

At subsequent autocrosses, I could do hard starts with no issue, until the final St. Lac event, when we were getting runs every 10 mins. The first couple of launches were fine, then I got clutch slipping again, at launch and on the shift to 2nd.

Also drove another NA at St. Lac realised my engagement point is pretty damn high in comparison.

Tracking at 'bogie and MIR wasn't an issue.

I'm wondering if:

a) I'm just overheating it at launch and I need to be a bit kinder.
b) If the clutch is maybe on it's last legs.
c) Something else may be at play like hydraulics, pedal adjustment etc that I need to look at before buying a new clutch.

Cheers,

Barry

elementZ
10-31-2011, 07:03 PM
check to see if your slave cylinder is leaking. that's normally a common problem.

SajBT36
11-01-2011, 04:12 PM
Thanks, will check that out Amaar. Also, looking yesterday, the clutch fluid looks like something that was drained out of Michael Moore's ears. Could be part of the problem!

Cavemanrjc
11-03-2011, 08:20 PM
hi guys sorry for the late input. the hydraulic portion of the clutch is only to release it. a leaking slave or master will cause premature engagement or clutch creep. sitting at a stop peddle fully on floor and clutch starts to engage. with the high engagement and slipping when abused i would think that the disc is just about done or the fingers on the pressure plate are worn or the plate is weak, also the valve covers tend to leak as with the distributor o ring. both cause oil to run down the bell housing. if the trans is not sealed fully to the engine it will cause contamination of the clutch. but engagement would be normal. a trick used on hondas is to use rtv silicone on the trans. they have a lot of coolant leaks right above the trans ;) as you are using the car in a sporting manner i would suggest a quality clutch kit including new disk, pressure plate and throug out barring. like o say a bully clutch. ;) get the flywheel machined and seal the trans to the engin when you reinstall it. when its apart if you see any oil from the main seal that's the time to change it. befor it contaminate the new disc. no i don't own a miata but i do see my fair share at work. hope this helps. also lube the input shaft of the trans with a high quality high heat lithium grease. not a petroleum based one.

kreutz73
11-04-2011, 09:16 PM
leaky slaves do cause weird things. the miata clutch pedal is also finiky, plus if your rear main seal is on it's way out then you will see it leak all over the clutch when it's running hot. put a new clutch in and replace the rear main when you are in there (do it carefully).

to test pedal engagement... put it in gear, car running and slowly let your foot off the clutch, the car should start to bog almost right away... the miata requires a long pedal throw, so if it doesn't engage near the floor you might want to adjust it. otherwise you might be riding the clutch even if your foot is off the pedal.

SajBT36
12-18-2011, 08:20 PM
Somehow missed you replies until now. Thanks for the input folks.

I'm starting to think rear main seal is more than likely. Have some engine oil coating the oil pan and transmission.

Just when I thought I was getting on well with my suspension job...

How much fun would the seal, clutch and flywheel be to replace for a shadetree mechanic like myself with basic hand tools?

kreutz73
12-21-2011, 12:11 AM

SajBT36
12-21-2011, 10:50 AM

kreutz73
12-22-2011, 08:08 PM

mikewolf
01-02-2012, 09:32 PM
Yeah. Who else but Tashko insists on only eating Greek food? So demanding.

SajBT36
01-02-2012, 09:53 PM
In that case, I'll only come if there's potatos and lucky charms.