<p></p><p>FTFY&nbsp;<img alt="Giggle" src="https://www.miataturbo.net/images/smilies/gay.gif" style="height:21px; width:15px" title="Giggle" /></p>

Also true.

I can't prove anything but I speculate that very light flywheels and unsprung discs contribute to Bundy's collection of broken 6 speeds. He probably needs much stronger than normal springs in the discs to operate properly, but I think most cars should use them to reduce mechanical shock. The guy building the disc needs to put springs in his that are designed for 400ft/lbs. and might not be. It may not be THE answer but for my 2 cents I think it could help.

But math can. I 100% agree with you. It can be shown to be true with math.

I run a stock 18lb flywheel and a sprung organic clutch, sold my 10lb flywheel.

Someone posted in my thread I made about this topic with good info from aircraft applications where this is well accepted.

Someone sure did
https://www.miataturbo.net/suspensio...trength-83376/

Hey it was you! Nice. You have my respect.

:likecat:

ACT throw out bearing ok? Or do i need to spring for the pimpy FM deal as well?

I just used the one that came with the kit. I dont see a reason not to.

One of the things a flywheel does is store energy to be released when power is not being added by the engine. It was discussed in the other thread that the peaks on the graph would not be as high, which is true, but the valleys where the crank is slowing down would not be as low. It reduces the peaks and raises the valleys to create a more linear power application. I'm contemplating going to a stock flywheel with the 6 speed and 3.63 gears to see if the trans will last at higher power outputs.

<p>Do it for science</p>

It must be a really lightweight 1.6 flywheel, given that both Happy Meal flywheel options are lighter than the OEM 1.6.

......

Not sure if trolling.

Not a good day. Clutch install itself went great. Going to like the clutch i think, seems super easy to drive when i'm not fighting other issues. (Read below.)

Noticed after a whopping 2000 miles, the fluid in my master cylinder reservoir was black and silty-looking. Threw enough fluid through it to clear it up and re-bled.

Pedal is super inconsistent and no matter how high up i adjust it, the clutch refuses to disengage completely 85% of the time. 15% of the time it works perfectly. 85% of the time i have to put waaaaaay more force than should be necessary to get the car into 1st or reverse, and it shifts like garbage otherwise.

So i replace the slave and bleed the helllll out of the clutch. Slave cylinder was bad (Is 2000 miles all i can expect out of the slave 949 sells?) Ran the entire system dry, then started over. Bled until no bubbles, then did 10 more cycles.

Re-adjusted clutch. The fact that it DID need re-adjusting, again, tells me that something was amiss.

Same exact thing is still happening. Going to replace clutch master cylinder tomorrow on the offchance that it too is bad within 2000 miles. Replaced both from 949 Racing at the same time.

No matter how i adjust the clutch, whether it's engaging right off the floor, or around my ears, it still won't consistently disengage. Anywhere between right off the floor and around my ears results in no change in how "badly" it fails to disengage.


Details:
2000 Miata
Slave cylinder replaced 2000 miles ago with 949Racing unit
Master cylinder replaced 2000 miles ago with 949Racing unit
Slave cylinder replaced again 60 miles ago with Duralast unit (today)
ACT HDR4 clutch (Installed today) 1.6 flavor
Ebay lightweight flywheel (Installed today) 1.6 flavor
949Racing stainless braided extended clutch line 2000 miles ago
Amsoil Dot4 fluid
Clutch and flywheel bolts torqued to spec and triple checked.

At a loss here. Don't have another vehicle to drive at the moment.

I think my 99 miata takes DOT3 fluid. Not sure if your setup is designed for that fluid?

Do you have any leaks?

Your description sounds like air or moisture in the system. The dirty fluid part sounds like it needs to be flushed. Both easy to fix. I would remove and bench bleed* the master, flush the lines between it and the slave cylinder. Then reinstall everything and bleed it correctly**.

* If you didn't bench bleed it when you replaced it, you gotta do that with a new master cylinder or any time the resevior allows it to suck air.
**Have to bleed it correctly or pedal will still suck as you describe.

How are you bleeding it? If you are one-man bleeding it, I highly recommend hooking a hose from the bleed screw that goes into a little bottle, hose end all the way in the bottle. As you bleed it, the fluid level will go above the bottom of the hose, so when you let off the pedal, it can suck in old fluid, but it can't suck in AIR. Same method for brakes too allows you to bleed/flush brakes by yourself too.

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<br />I bet monk is on top jamming the rod into the cylinder.

Monk smash.

I don't understand?

No.

Like i said, i did. Fluid was FAR dirtier than it should have been for the miles.

Did it.

I bench bled it when i replaced it, worked fine with the old clutch. Or at least seemed to. Hard to tell with a worn out clutch, but at least it would disengage properly.

2 man, and there's a speed bleeder installed. I've replaced hydraulics on a few of my cars, including 4 Miatas. ;)

Though... i'm starting to think that maybe i'm doing something wrong. I had chronic disengagement issues on my 95 turbo car with FM1 clutch, but the pedal was at least always consistent.


The amount of crap in the fluid was what i normally see with a bad seal somewhere. My theory is that one of the cylinders died, and the resulting debris took out the other one. Just ordered a replacement Exedy set, will be here tomorrow. Nothing like having 2.5 sets of hydraulics on your car in 2000 miles, right?


Nah, that'll be Friday.

Actually no, was busy responding to non-existant house fires because people don't know the difference between a fully involved structure fire and smoke coming out of a chimney.

If I were, I would have bench bled.

You are having shitty luck with all your expensive parts.
Obvious solution is to only buy cheap things.

My guess is you are doing something wrong too. My guess is you got air or moisture in the system. Does it work fine when cold, but goes to shit after 20-30min of driving? If so, moisture. If shit all the time, air.

How interesting.

When I parked the car the clutch worked fine, every bit of it. After the ACT install, the clutch just wouldnt bleed, or build pressure; it was sucking air past the seal in the master.

I always replace both at once. And fwiw, I only got about 5k with duralast parts.

Also, installed both entirely dry, had the clutch bled in about 3 minutes, within maybe 10 cycles with the wife in the drivers seat and me under the car.

So... What fluid did you use?

Pat. Read up on brake fluid. It's hard to take you seriously between your refusal to read what was posted and your apparent ignorance of brake fluid.

As long as he didn't use motor oil or silicone based (dot5?) he is fine. I used O'Reilly mega awesome dot4

DOT3 and DOT4 are completely cross-compatible.

Have you blamed the clutch yet? They often act weird while they're being broken in. How nice have you been to it when you have driven it?

lol, sorry for wasting your time trying to help you troubleshoot your problem

The only fluids that aren't compatible are the silicone-based.

I haven't blamed the clutch yet, but i haven't noticed this behavior in any other clutches i've installed. At least not the inconsistent part. When they refuse to disengage entirely, they typically do so consistently and can be adjusted out.

I've been pretty nice to it. I've run it up the RPMs, but i haven't been banging gears hard or doing clutch drops or anything.

I mean, i appreciate you trying to help, but your two main points are a non-issue and something i specifically said i did in the first post when i described the issue and what i did about it.


Anyways, i'll replace both cylinders again after work today and re-bleed, see if i can't get some love out of this. Still had to drive it to work this morning, my poor transmission. Loving the clutch/flywheel combo otherwise. Definitely added some NVH but this car already had that in spades, so whatever. Revs stupid fast and made a noticeable difference in "pull" in the first couple gears.

Have you ever thought of swapping in a nice 1.6 motor? I hear they rev amazingly and nothing is better.

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<br /><br />
<br />This has amused me to great end this whole thread.

It's because the parts are smaller, and therefor lighter, right?


That's really the thing that frustrates me about all this. The Miatas have been the one car historically that i haven't cheaped out on. Barring the Escort, i've also had the most problems with them. The MX6 is NOTHING but hackjobs but never gave me 25% the problems i've had with Miatas. :giggle:

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<br /><br />
<br />Its because there are fucktards in this world and they reside on m.net.

Replaced hydraulics. Bench bled. Used the correct fluid that my system was designed for. Bled the hell out of it.

No change.

I'm at a loss at this point. Any ideas? Car shifts like garbage (Which is especially vexing because i bought a $400 shifter/knob setup to make it feel perfect, and it did on the last clutch) because i'm fighting synchros, refuses to go into 1st or reverse from a stop.

I hate to say it, but youve kinda ruled everything out but the clutch.

Adjusted the pedal correctly?<br />
<br /><br />TOB installed backwards? Clutch fork bent. Idk throwing out silly ideas.

Yeahhh. This sucks. Now that i've run through $55 in hydraulics and probably $40 worth of brake fluid.

I don't have time to do this again. Guess i'm going to have to get a rental and farm it out.

Yep. I've moved engagement point anywhere from right off the floor to up around my ears. Has zero bearing on the issue.

I've probably replaced 100 clutches in my life time, and I've only had one do this exact thing. It was a stock replacement sachs that had a fucked up pp diaphram. When we went to remove it, it was clear as all the fingers were at a slightly different angle.

This displeases me. The other theory that might make sense is that the flywheel maybe has a small amount of runout and i should have checked it?

Is it possible to install a TOB backwards?

Local buddy says he's seen a bunch of Mazdas in general with bent forks, but i hadn't heard of that before. Any way to check without dropping trans again?

Did you not resurface it? Even then i don't think so, it would shutter and squawk, but it would still release properly i would think.

I did not. There was extremely minimal hotspotting and was in generally very clean condition with no glazing. Brake cleaner and a quick pass by hand with a scotchbrite pad.

I forgot to drop it at the machine shop and took a gamble, figuring i could live with some shuddering and noise if i had to for a couple months before tearing the car down this winter again. THIS wasn't something i would have expected though.

Can't the clutch disc go on backwards? I seem to remember someone doing that once.

It can.

It's not LIKELY that i did such a thing, having done a clutch or dozen before and never made this mistake, largely due to the large stickers clutch manufacturers put on them that say "THIS SIDE TOWARDS FLYWHEEL," but it's a possibility. I did not double check this, as it's been something that i haven't had an issue with.

But hey, if that's the case, i'll definitely let you guys know i did that and you can all point and laugh at my expensive and time consuming mistake. Looks like i'm dumping another $40 of trans fluid on Friday.

why not just drain it into a clean bottle and reuse?

or get/make a tailshaft plug and no need to loose any trans fluid. I could send you mine to borrow if time wasnt an issue, offer stands either way.

<p>What he said. Tailshaft plug. No use wasting trans fluid.</p>

I have a shitload of spare fluid that i bought for the Jeep that i never got to use because it got totaled. Not the biggest deal in the world. And i'm a weakling so the idea of chest pressing this transmission with even a pound more weight in it from fluid sounds awful.

<p>Put some weight on and learn to bench bro</p>

I don't even lift bro.

Trying to lose more weight so my n/a Miata is faster. I think 135-140lbs should be nice.

<p>I'm seeing how much I can gain without not being able to sit in my seat anymore.</p><p>I tried staying skinny for rowing. I like ice cream too much for that bullshit.</p>

I still eat ice cream 3-4x a week. But i'm down over 20lbs this year already. I don't have time to nourish and maintain a big buff bear body.

<p></p><p>I prefer every day.</p><p>I don't cook so i just eat large quantities of whatever my gf makes for me.</p>

I cook, so my wife eats large quantities of whatever i make for her.

I'll see if I can bring my bear body down to help.

We might actually have a lift available for a hundo or so of my dollhairs. If so, we're talking a 2 hour job, plus whatever it takes to get the flywheel resurfaced. I don't want to spend money, but i also don't feel like doing this job on my back in my driveway and wouldn't want to subject you to that. If we can knock this out quick, then we have better chance of knocking out rollbar.

A step forward towards closure: The clutch disc is defective because my luck is super awesome.

All four pads thicker than spec. 3 of them slightly, 1 of them big time.

ACT sending me a new disc, but might not be here until Tuesday, which is not so awesome, considering i leave Wednesday morning.

I would want a new PP too, seeing how its been partially broken in on uneven frictions.

At least it wasnt your fault and youve found the issue.

oh, and have the FW checked this time if not at least surfaced for good measure.