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-   -   Sanity check before I replace a clutch on my MSM (https://www.miataturbo.net/suspension-brakes-drivetrain-49/sanity-check-before-i-replace-clutch-my-msm-99811/)

delturcious 04-10-2019 11:45 AM

Sanity check before I replace a clutch on my MSM
 
Pretty sure I have a bad pressure plate (I've read about springs breaking?), but I'm hoping to get a sanity check before I buy a new clutch/flywheel combo. Leaning toward the SM 1.8 organic disc and 13.9# flywheel since there seem to be a lot of complaints about shuddering on the FM happy meal.

Car:
  • 2004 MSM with ~142k miles
  • FM intake
  • ARTech exhaust
  • Stock boost level
Symptoms:
  • Can't shift in or out of gear at medium (~4k) RPM; worse at higher loads
  • With engine running, car in neutral, rolling backward into my garage, transmission grinds when attempting to shift into reverse
  • Clutch is NOT slipping

Things I've replaced/installed with no effect:


  • Engine mounts (were trashed anyway)
  • Upper/lower shifter boots (also trashed)
  • Shifter end bushing (you guessed it, toast)
  • Stainless clutch line
  • Exedy clutch slave (figured might as well for $6 while replacing the line... no effect)
  • Rear subframe brace (feels great at low RPM, but no effect at medium/high)
  • Clutch pedal adjustment (dialed a little free play out of it, but no effect)
I took a video of the clutch slave/fork movement if it would help to post it, but it looks normal to me. Normally I'd guess a bad hydraulic system with these symptoms, but all that seems fine.

At this point I'm guessing it's either the clutch or the trans. Any other ideas? Thanks in advance!

EDIT: Disc has chunks broken off around the springs, and pilot bearing fell out. Pics in the posts below.
EDIT 2: Even before break-in period is complete, new clutch and flywheel fixed everything.

curly 04-10-2019 01:32 PM

I think the grinding into reverse may be normal. Can you shift without a clutch smoothly? If not, it sounds like a transmission issue, not clutch.

delturcious 04-10-2019 02:18 PM


Originally Posted by curly (Post 1530403)
I think the grinding into reverse may be normal. Can you shift without a clutch smoothly? If not, it sounds like a transmission issue, not clutch.

I haven't tried totally without the clutch (I actually haven't driven it in months), but if I rev match at low RPM & low load I can shift as smoothly as a 6-speed can. I'd rather swap a 5-speed in, but the consensus seems to be third gear WILL eventually fail on those.

It's an original clutch, so it probably needs to go anyway, but is there anything I can check/replace on the transmission while it's out?

Also forgot: changed out the Redline fluid that had been in ~30k miles for synthetic Motorcraft.

tyhackman15 04-11-2019 11:25 AM

At this point, you're pretty much going to have to take the trans off regardless, I'd order a clutch either way at 142k miles.

Find a very slight incline, stop, put the car in first and keep the clutch depressed, does the car roll backwards or hold itself? Easy to tell if you're getting proper disengagement that way, in my experience.

sixshooter 04-11-2019 12:04 PM

Fluid that is too slick can keep synchros from doing their job well and can make the gears grind sometimes. How in the world did you keep a stock clutch for 142,000 miles?

MetalMuffins 04-11-2019 02:18 PM


Originally Posted by sixshooter (Post 1530563)
Fluid that is too slick can keep synchros from doing their job well and can make the gears grind sometimes. How in the world did you keep a stock clutch for 142,000 miles?

150K miles on stock clutch checking in. :ugh2:

sixshooter 04-11-2019 02:23 PM


Originally Posted by MetalMuffins (Post 1530600)
150K miles on stock clutch checking in. :ugh2:

You must have a very gentle touch sir.

x_25 04-11-2019 02:32 PM

Duno how it compares to Miatas, but my co-worker has 198k on the stock clutch in his 05 Civic Si.

cpierr03 04-11-2019 02:57 PM

Your symptoms sound similar to a buddy of mine that broke a pressure plate tang off an ACT plate.

I don't see master cylinder in the list of replaced parts - its a maintenance item that should be replaced with the slave IMHO, they're fairly cheap anyway.

FWIW SPM Organic clutch w/12 lb flywheel has been the most pleasurable clutch experience I've had in any car to date.

delturcious 04-11-2019 03:44 PM


Originally Posted by tyhackman15 (Post 1530553)
At this point, you're pretty much going to have to take the trans off regardless, I'd order a clutch either way at 142k miles.

Yep, I've resigned myself to that. I'll grab a trans jack from HF this weekend and will hopefully have time to yank everything apart Sunday.


Originally Posted by sixshooter (Post 1530563)
Fluid that is too slick can keep synchros from doing their job well and can make the gears grind sometimes. How in the world did you keep a stock clutch for 142,000 miles?

Redline and Motorcraft both seem to be highly recommended, but swapping fluids didn't do a blasted thing. My 94 had ~222k on the original clutch (bought at 208k; PO didn't drive hard at all). I've had this one since 108k (34k miles in 7 years), though it's only been on a track twice with me :dunno:


Originally Posted by cpierr03 (Post 1530606)
Your symptoms sound similar to a buddy of mine that broke a pressure plate tang off an ACT plate.
I don't see master cylinder in the list of replaced parts - its a maintenance item that should be replaced with the slave IMHO, they're fairly cheap anyway.
FWIW SPM Organic clutch w/12 lb flywheel has been the most pleasurable clutch experience I've had in any car to date.

I've read about a few broken tangs, so I may have some interesting photos to post in a few days. I haven't bothered with the master, though it's not leaking (yet)... you're right though. Thanks for another vote of confidence on the SPM organic... still waffling on the flywheel, but I'd probably regret just resurfacing the OEM one.

cpierr03 04-11-2019 03:51 PM


Originally Posted by delturcious (Post 1530616)
haven't bothered with the master, though it's not leaking (yet).

Clutch master usually doesn't visibly leak - just blows fluid past the seals and doesn't build sufficient pressure.

delturcious 04-11-2019 03:59 PM


Originally Posted by cpierr03 (Post 1530618)
Clutch master usually doesn't visibly leak - just blows fluid past the seals and doesn't build sufficient pressure.

Oh. Does this look normal?

curly 04-11-2019 11:55 PM

Yes. You can pull the boot back and look for leaks, but a leak really only affects you at a stop with the clutch in. It’ll eventually bleed down and release the clutch. A shift at speed should require little to no clutch disengagement.

borka 04-12-2019 08:06 AM


Originally Posted by sixshooter (Post 1530563)
Fluid that is too slick can keep synchros from doing their job well and can make the gears grind sometimes. How in the world did you keep a stock clutch for 142,000 miles?

Years ago I owned a 2001 nissan maxima 5spd. Bought the car at 90k miles with original clutch.
Drove that car till it died at 230k miles. Still on a perfectly working original clutch.

delturcious 04-14-2019 02:39 PM

I'm fairly confident the problem here has been identified. In addition to the broken pieces around the springs, the pilot bearing fell out before I even pulled the flywheel off. Guess that makes my decision for me on a new flywheel too.

https://cimg3.ibsrv.net/gimg/www.mia...c96b67436d.jpg
https://cimg9.ibsrv.net/gimg/www.mia...637ece28ab.jpg
https://cimg2.ibsrv.net/gimg/www.mia...fd73b0fc79.jpg
https://cimg6.ibsrv.net/gimg/www.mia...4f03b27e1c.jpg


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