Strange Wear on ACT Pressure Plate

[belize1334]

So my clutch went south on me and after pulling the transmission I discovered that my ACT Street-Disk had popped a spring. I was surprised to find though, that the friction material wasn't that warn despite me putting about 20k miles on this clutch over the course of 5+ years of driving.



So I think to myself, perhaps if it's just a pre-mature disk failure, maybe the pressure plate is reusable and I can save myself some cash. Upon inspection, the springs are all still good, there are no popped rivets and the surface isn't cracked or pitted or even noticeably warped. Then I pull out my straight edge and lay it across the surface and this is what I see.



I seems that the pressure plate itself has warn down by about 1mm more on the inner radius than on the outer radius. It's enough to convince me that I need a new pressure plate. I've been trolling the web on and off for about two days now and I have yet to see an image or hear tell of another clutch doing this. Has anyone else seen this or is my car just being awesome again?

 

[belize1334]

Hm...

A little more searching revealed this thread.

Cliff-notes. According to ACT this is caused by torquing to the factor recommended value instead of the ACT recommended 27ft-lbs. Also, the rep said it's reusable as long as the difference is less than 1mm? Your thoughts please.

 

[Brianawd]

I have seen that with every act I have ever owned. Now what you need to do is put the disc on the splines and see how much it moves. Back in the old day the disc would fit the spines nice and tight with not movement. Now it seems that even with a new disc they do not fit the splines tight so the disc is able to move around. That is the reason for high rpm lock out and uneven wear of the disc.

 

[belize1334]

The disk was nice and snug on the transmission splines but w/ that spring popped it's certainly shot. The main question was whether the plate is done or if it's reusable. If it's done I'll just get a 2600 w/ street disk. If it's reusable I'll get a sprung 6-puck and keep it on the 2100 pp. The friction surface on the pp looks basically fine but that slope has me thinking it'd eat through a new disk pretty quickly and I certainly don't want to be doing this job again any time soon.

 

[Brianawd]

Quote:
ACT recommended 27ft-lbs



torquing the bolts to 27ft/lbs ends up braking them. If your going to do that you need to get new bolts that are stronger.

click

I have put a few of there in cars and love them.

 

[belize1334]

^^ I agree that 27ft-lbs seems like a lot for even a high grade 8mm bolt and I definitely don't want to break on off in the fly-wheel. Last time I used OEM bolts at 12ft-lbs as per Mitsu recommendations. Next time I'll get some grade:10.9 and torque to ~20 as a compromise.

The 6-puck idea was intended as an upgrade that would allow the reuse of my pressure plate. Since it looks like I'll be replacing anyway I think that I'll probably go 2600 s/ street disk. This is after all a daily driven street car and I'm not really excited about having a track-only clutch in it.

 

[Brianawd]

These may be better for what you do with your car

click
click

 

[belize1334]

I'd love one of those but I have to be nice to my wallet. Graduate students can't be choosers. Thanks for the input though. How's Portland these days? I bet it isn't 40* and snowing /ubbthreads/images/graemlins/bawling.gif .

 

[Brianawd]

Its been nice. this coming week temps are going to be in the low to mid 70s. It has been snowing in the Mountains. I'm ready for the rain and cool days /ubbthreads/images/graemlins/grin.gif

 

[belize1334]

Sanity check. I found a guy who will sell me a 2600 pp w/ less than 900 miles on it for $150. Seems like a deal and he says it's flat. BUT, he says that he put it on a resurfacing machine just to ensure flatness. He says that the machine took off essentially NO material since the disk was so new. My question is, should I be worried that there is some kind of surface treatment that has been compromised by the removal of a minute layer of material?

 

The only way you can resurface the pressure plate friction surface is by diassembling the pressure plate, which would require the entire assembly to be rebalanced. More than worrying about any surface treatment I'd be concerned that it wasn't balanced properly if at all.

Daryl

 

[dmj]

You can get the Forced Performance Dsm flywheel kit for $ 45.00. the studs are good for 28 lbs of torque for the pressure plate.

 

[belize1334]

Talked to some folks at ACT who informed me that the new style of disk demands the new style of pressure plate. The new disks won't fit under the old pressure plates unless you go unsprung.

On a side note...who has experience with Spec Clutches. This one looks interesting. Also available here. and both sites offer free ground-shipping. Anyone have experience with either of these sellers?

 

I've used Spec and ACT clutches on Sentra's and all of them spit a spring sooner or later.