clutch help, i keep breaking pressure plates

[di_rosa]

i keep breaking pressure plates (refer to pic below), and i'm fucking tired of doing clutch jobs every week. i've gone through 3 pressure plates, and every time, before it blows, everything is working perfectly, engages smooth, no shuddering/chattering, holds fine, no slipping, clutch pedal feels normal, and then on a 1st or 2nd gear pull (around 4.5k) boom, it breaks, engine starts wobbling (due to unbalance), and it's hard to shift into gears (due to pp not releasing because it is bent/broken).

the pressure plate is from a clutch shop that rebuilds pp's and makes them stronger via dual diaphrams, stronger springs, etc, etc. every time it has broken, they have replaced the rivets, bands, and checked it all out. i don't think it's the pressure plate as other people have the same pressure plate with no problems.

tranny is stock r154 from 86.5, however, my friend had it sitting outside under a tarp for a bit, and when i got it, water came out, but like i said, car drives mint before the pp goes.

slave cylinder is from a jdm soarer if it matters, master cylinder is brand new, using dot3 hydraulic fluid.

flywheel is from 1jz, and has all he dowel pins on there. bell housing is from soarer r154.

it's almost like the 2nd part of the pp (friction material part) is twisting away from the other part of the pressure plate.

thank you for any suggestions you may have. i am going to try one more time with a stock pressure plate, and see what happens, but i fear it may not happen again because the stock pp is slipping.

 

[IJ.]

About all they can do is add more drive straps and replace the rivets with grade 8 hardware minimum.

The rivets are just plain crap mild steel and are taking the entire load from the motor x the leverage from being so far out from the centreline.

 

[MDCmotorsports]

Either as Ian has stated, go with some grade 8 hardware or try the following:

-Stainless rivets. Stainless will acutally give a little before breaking
-D2 tool steel unhardend. Again, very strong material. Not brittle if un heat treated.

 

[IJ.]

Jon: They use the silly putty rivets in production as it takes less pressure to compress them and fill the hole in the plate but when using a hard rivet there's a fine line between filling the hole and exploding it! :aigo:

Not good when your press operator is a 15 year old kid working for minimum wage. (If ya can't guess I worked in the clutch industry for a few years when I was young)

 

[di_rosa]

if it was the rivets (which i've had replaced 2 times now), why didn't they break on the other people who are using the same pressure plate? mind you, one of the other people using it is running 26psi with no problems on that pressure plate, and the clutch shop keeps saying something is wrong with my car/setup

 

[IJ.]

Has the Trans/bellhousing been swapped out at any stage?

 

[di_rosa]

well the bell housing is from a soarer, and the trans is from a parts car that drove fine before they parted it (buddy of mine drove it home with no problems).

 

[malloynx]

you shouldn't be ripping out the marcel springs like that. id go with a name brand clutch. I'm runnning a SOUTH BEND and it sure does take a beating

 

[di_rosa]

yeah, i'm gonna probably try throwing in a stock pressure plate with an rps 6-puck disc and see what happens. if it breaks again, i know something is wrong with the tranny setup, but what i don't know??

 

[IJ.]

If the trans isn't in line with the CL of the crank it will do some bizarre shit.

 

[Joel W.]

Do you have a pilot bearing installed in the crank?

 

[supra90turbo]

I should hope he does, Joel!

Who is the manufacturer of the clutch?



Not much else to add, but I had a good laugh at "twigs".

 

[Joel W.]

I know it will cause a serious vibration at hi speeds if he does not, When I took mine apart, there was not a pilot bearing installed. Not sure if my motor was replaced from an auto car or if someone just forgot to reinstall it during a clutch job.

It would let the disc drop down when the clutch was pressed in throwing it severely out of balance.. Just something to check for..

 

[di_rosa]

yes, pilot bearing is in, i just changed it when i threw the engine in, and made sure to sit it at the same position inside the crank as the previous bearing.

the clutch is a local shop that makes clutches for a lot of the ontario, canada guys, including some other people one of which is running 26 pounds with no problems.

anyways, after the 4th pressure plate, i decided to try a stocker and see if in fact it really was the shop that messed it up 4 times in a row. i just took it for a short drive now and did a few pulls (damn cops are everywhere), but i know i have to do more pulls as it lasted for a 1.5 hour beating last time.

IJ
If the trans isn't in line with the CL of the crank it will do some bizarre shit.

IJ, what is "cl" ? and how can the trans not be in line with it if i have tightened down the bell housing bolts and there is no gap in between the two?

 

[IJ.]

Centreline

Sometimes when you mix and match parts they don't line up perfectly and can cause lots of problems.

Toyota have made it really hard to correct this on our bell housings though.

 

[di_rosa]

hmmm, well if it wasn't in line with it, wouldn't i get some hardcore vibration the faster i went? cause i've been up to 160 with no problems

and the disc and pp are from the same guy that and he used a stock toyota core to upgrade it.

ah well, i've been driving on the stock pp and disc for about 4 hours with no problems, so i'll stay like this for about a week and see what happens. if it doesn't blow, i'm gonna loose it on these guys, but if it does, i'm done, i give up. going auto

 

[supra90turbo]

going auto?
why not buy a GOOD clutch?

 

[di_rosa]

because i'm not convinced it is the clutch, and i don't want to buy a $1500 clutch and have it break after 1 day, not to mention the idea of pulling the tranny one more time makes me want to sell my fucking car.

 

[di_rosa]

well, broke the stock pressure plate today which proves it wasn't the clutch shop messing up. my friend gave spec and rps a call and they said whenever crazy shit like this happens, it's almost always the flywheel. but i know i had the flywheel machined, so i dunno, maybe the crank. i guess i'll pull the tranny and take some measurements.

 

[IJ.]

My guess is still bad alignment.