ACT pressure plate and broken clutch forks

[JustJeff]

I'm planning out the rest of my rebuild and looking for feedback from people using ACT clutches. I've been warned by a friend about ACT HD pressure plates breaking clutch forks. I spent some time on google reading. I spent some time on rx7club reading.

It seems like the pivot ball is what breaks on FC's. I also found this link about FD's
http://www.fdnewbieimports.com/Backup/product.php?n=43

Unfortunately I've never driven on an ACT, don't know anyone who has. Before I make a decision I'd like to hear as much as possible. I'd love to hear from people using them.

[speedjunkie]

I've had an ACT Xtreme pressure plate on my FD for 5 years and just put another one in, all on the original clutch fork. I'm pretty sure the one I have is even a step stronger than the HD, the one I have is the XT. I read somewhere that the 93 forks had a problem breaking but they upgraded them in 94, which is what I have. Not sure about FCs though.

Also I've heard recently that people have been talking a lot of smack about 6 puck clutch disks but I ran one since 05 and just put another one in this month and it was always fine, it was a sprung disk too btw.

[JustJeff]

Thanks for the feedback.

Feedback I've gotten on other forums is that the XT is stiffer than HD. I also found the same info about FD fork upgrades. I won't be going 6puck. I'm trying to get ahold of a guy who fabricates clutch discs but haven't heard back from him yet.

[TitaniumTT]

Comparing the FD to the FC is like comparing ........ two things that shouldn't be compared. One is a pull type, the other is a push. There are plenty of reports of the HD and XT PP's bending/breaking clutch forks, snapping pivot balls, and just wreaking havok on the hydraulics. The answer is a twin disc

But seriously, think about a twin disc. Less pedal effort, more clamping power, less stress on the hydro's etc etc. I LOVE mine and will definately do another in the FD.

The key is to get the least amount of clutch that you need. ACT has ratings on their website and when I spoke with them they informed me that they are wheel hp rated torque numbers. There's no need for a XT PP with a puck clutch when you're making 300ft/lbs of torque. In fact, I just looked it up, the HD PP and street disc holds 380ft/lbs of tq.... A 34% increase in clamp load shouldn't break/bend much

[JustJeff]

What happened to my thread? Half the posts are gone?

[RETed]

Hosting server crashed.
Lost last 14 hours of posts.
See Lounge for more details.



-Ted

[JustJeff]

That sucks...i'll check it out, though I do hate lounge stuff. All kinds of shenanegans go on in those places :P

[JustJeff]

For the time being I'm leaning towards keeping my Exedy OE pressure plate and replacing the OE disc with an ACT disc.

What Ted (before the HD crash)and TTT said about hydraulics hit home. I'm doing this rebuild for reliability first. I don't mind rebuild/replacing hydraulics. I did that for my father's vert. But the thought of having to drop the transmission to replace a pivot ball makes me want to kick a kitten..or maybe a crack whore. Hell...it would cause me to kick both of them.

One question, can I expect to get more miles out of an ACT disk? The mileage I got out of my Exedy didn't have me all that excited.

[TitaniumTT]

If you're that opposed to dropping a tranny, and honestly I don't blame you, I towed my car to Dave the last time I would replace them both, and get the flywheel machined. Although (is this a Turbo or N/A car?) the machine shop that I used, last time I replaced the clutch in my mothers Jeep, it was cheaper to buy a new flywheel, than get it machined ($80 - I pay wholesale prices on parts, but full price on labor). Both the disc and the PP will have an effect on life. The springs can fatigue, the disc obviously wears, warpage etc. I've not used an Exedy OE kit so I can't give an honest opinion on it but I will say the centerforce DF that I used lasted like 10k and the disc looked like it had alot of life left in it. That thing blew.

At either rate, I would replace them both..... or get a twin disc

[antman0408]

I thought it was just the XT PP that was breaking the pivot balls and clutch forks. I have 14k miles on my HD PP and disk and have no problems with those. The slave cylinder did go after a couple thousand miles so I replaced both the master and slave cylinders, haven't had a problem since.

[classicauto]

ACT HD with a street disc will be the clutch for 90% of street use. I've had one in my FC for......damn it i don't even know how long. Too long. Because its finally starting to slip @ 20psi (~400whp+++) Best guesstimate on street miles on that HD clutch.......50,000kms or so. Mines been in roughly that long (roughly, its been years) and has only this year started slipping at higher boost settings that net over 400whp. Thats mostly street miles, not pussy miles, just street miles!



You won't bend or break anything in the transmission with this clutch as far as the heavy pressure plate is concerned. Its only when you get into the extreme plate that things start bending. The extrreme PP's have stupid heavy pedals....if you need to hold more the 380ft/lbs at the crank - buy a twin plate.

[JustJeff]

Originally Posted by TitaniumTT

If you're that opposed to dropping a tranny, and honestly I don't blame you, I towed my car to Dave the last time I would replace them both, and get the flywheel machined. Although (is this a Turbo or N/A car?) the machine shop that I used, last time I replaced the clutch in my mothers Jeep, it was cheaper to buy a new flywheel, than get it machined ($80 - I pay wholesale prices on parts, but full price on labor). Both the disc and the PP will have an effect on life. The springs can fatigue, the disc obviously wears, warpage etc. I've not used an Exedy OE kit so I can't give an honest opinion on it but I will say the centerforce DF that I used lasted like 10k and the disc looked like it had alot of life left in it. That thing blew.

At either rate, I would replace them both..... or get a twin disc

This is a turbo swapped vert. I've got a full turbo drivetrain:tranny, shaft, diff, etc.

You are right about replacing the pressure plate. I'm walking the dichotomous line of both wanting reliability and to save a buck. Somethings gonna have to give. I guess I'm not so opposed to doing the work of transmission. It's more that I have a hard time getting friends to help me out. My most reliable car friend will on days we are gonna do work txt me at 1PM with a "sorry, I just woke up"

The Exedy plate seems to be in great shape. Before I decide anything I'm planning to let some more experienced people physically inspect it and get their opinions.

Originally Posted by antman0408

I thought it was just the XT PP that was breaking the pivot balls and clutch forks. I have 14k miles on my HD PP and disk and have no problems with those. The slave cylinder did go after a couple thousand miles so I replaced both the master and slave cylinders, haven't had a problem since.

Originally Posted by classicauto

ACT HD with a street disc will be the clutch for 90% of street use. I've had one in my FC for......damn it i don't even know how long. Too long. Because its finally starting to slip @ 20psi (~400whp+++) Best guesstimate on street miles on that HD clutch.......50,000kms or so. Mines been in roughly that long (roughly, its been years) and has only this year started slipping at higher boost settings that net over 400whp. Thats mostly street miles, not pussy miles, just street miles!



You won't bend or break anything in the transmission with this clutch as far as the heavy pressure plate is concerned. Its only when you get into the extreme plate that things start bending. The extrreme PP's have stupid heavy pedals....if you need to hold more the 380ft/lbs at the crank - buy a twin plate.

From what I've read so far you are correct. It's the XT plate that is causing problems. One guy with an HD broke his pivot ball, but who knows how close it was to going regardless of the plate.