So last night I broke the third freakin' clutch in 6 months...

[Rinmax]

Sounds like a good theory.

If you want to try a stock flywheel I have a spare you can borrow.

PS. Love the pic so much it is now my desktop wallpaper.

[Celica RA45]

i always use loctite on the f/wheel bolts so nothing comes a drift

[LeeRoy]

Is it breaking all the straps on every side of the clutch or just the straps in 1 spot?

- LeeRoy

[TA-022]

yeah its just something about 'cast' and 'machining' tells me they should never be in the same sentence

[twentyEight]

Is it breaking all the straps on every side of the clutch or just the straps in 1 spot?

- LeeRoy

Just one spot... The others crinkle because they then have all the load and don't have the third strap to hold the whole thing in place properly...

[lexsmaz]

Do these motors have just a solid steel front crank pulley or a proper harmonic balancer setup, ie ; a rubberised outer ring etc ... if its the harmonic style rubber outer ring the rubber might be slipping on the pulley a hence not dampening out the harmonics ... Just a thought ....
Also makes me wonder when they balance up the pressure plate assembly, do they balance all the individual components, ie; cover, pressure plate cast ring, etc, or do they do it as a completed unit only .. I wonder if the cast ring ( clamping drive ring ) is actually out of balance quite badly & they only balance up the complete unit, so when you depress the clutch the main clamping area has a massive wobble especially at high revs causing the strapping issues ? ...

[allencr]

"Just one spot", so now it's obvious that it's 3 for 3 in the same place where you've center punched the flywheel, not that the marks do anything, and that it should've & would've been random if it was a pressure plate problem, or the flywheel was symmetrical.

It happens at high RPM with no load, compresses/kinks 2 of the 3 and tensions/stretches/breaks the 3rd strap.

I don't understand why it doesn't vibrate in the extreme!!

[The Real Roadrunner]

a twin plate would fix it but its an expensive option. something is certainly wrong with your setup.
ive seen bands on clutch plates snap due to misalignment but never this.
missing a gear shouldnt make two shits of difference (just like having a large ratio spread) unless the box is out of balance but that wont cause a prob for the input shaft balance as they run to the layshaft first and your box would vibrate.

does the fly wheel run true to the back of the crank as this may cause it to break at the same point and loosen the flywheel bolts or shear them.

id run a lightened alloy/steel fly/upgraded clutch as i believe this would get rid of the prob area. if cost is a prob think of all the R/R you've been doing and the tows you've probably paid for and its cost would be minimal.

im voting for the oldschool 2T theres just something tough about them you wont get with a beams.

[abently]

Just to be sure, get a generic extra long Bolt and turn it into the Crankshaft with the Flywheel. Mark it once its all the way in and then pull it out and make sure you've got 3-4 turns of full thread left in the Crankshaft itself when comparing it to the original Flywheel Bolts. This won't fix the 'breaking straps issue' but it should resolve the shearing Flywheel bolts.

[LeeRoy]

Just one spot... The others crinkle because they then have all the load and don't have the third strap to hold the whole thing in place properly...

I'm curious (not bi curious ) as to whether it is actually breaking them in the same spot relative to the crank. If this is the case then clearly it is not a clutch issue but sounds more like a balance issue. What i would suggest is if your going to put another clutch in then mark the flywheel in relation to the crank and put the clutch back on and then in relation to the crank have a look at what position it is breaking the straps.

- LeeRoy

[twentyEight]

Fair coincidence if he's put a clutch on three times in the exact same position...