What is the final consensus on the Exedy Twin Disc?
Thread Starter
Joined: Aug 2011
Posts: 2,154
Likes: 5
From: Philadelphia, PA
On my exedy twin sd i got around 25k out of her until i couldn't put her in 1st anymore (did pedal adjustments, etc). Got it replaced with a twin hd which lasted me 20k. When i took it out however, the disks had plenty of life, and I was told that it was the middle plate or the floater plate that causes issues with lockout. You might just need to resurface the plates, but either way you will have to pull the clutch out and rebuild it.
The ACT street discs are superior to the Exedy twin disc as far as daily driver longevity goes. Given torque isnt too high... I haven't read about too many exedy's on here lasting 50k+ miles, while it seems to be pretty common to see the ACT's last that long. Some have lockout issues some don't. Don't read about near as many Exedy's with lockout issues.
http://www.jackstransmissions.com/pa...clutch-warning
This might help you out. Requires removing the clutch assembly but worth it in the long run.
I'm amazed that no one has posted this up yet. No one heard of this problem?
We have noticed a problem with the Exedy twin disk units for the EVO 8-9 that people are mistaking for a trans problem. If you are using an Exedy twin disk clutch, please note some have a problem of sticking at idle when the clutch is depressed which will cause the trans to feel terribly notchy when shifting into gear from a stop. This is happening due to insufficient floater plate to basket clearance. The floater is cast and the basket is not. The difference in materials cause the assembly to stick when the vehicle warms up as the parts are expanding at different rates, so the floater will not let go of the disk and cause a low RPM clutch drag issue. To prevent this problem we recommend the following before installing our trans when using the Exedy twin disk:
1)Disassemble the clutch assembly.
2)Polish the area on the basket that makes contact with the floater (the arms).
3)Polish each side of the arms around the basket thoroughly.
This will prevent the floater from sticking by adding more clearance and a nice polished smooth surface for the floater to make contact with. When done correctly, your new trans will shift perfectly at low RPM!
1)Disassemble the clutch assembly.
2)Polish the area on the basket that makes contact with the floater (the arms).
3)Polish each side of the arms around the basket thoroughly.
This will prevent the floater from sticking by adding more clearance and a nice polished smooth surface for the floater to make contact with. When done correctly, your new trans will shift perfectly at low RPM!
I'm amazed that no one has posted this up yet. No one heard of this problem?
Last edited by Piro Fyre; Sep 22, 2011 at 05:05 PM.
The ACT HDSS was my previous clutch, and I had lockout. Since I found out how to properly bleed the clutch (after I installed a new/different clutch), that may have been why I was getting lockout. Most people, like myself, wanted to blame the tranny first, but it's almost always been the clutch not fully disengaging.
Thread Starter
Joined: Aug 2011
Posts: 2,154
Likes: 5
From: Philadelphia, PA
I have to tear the clutch out either way in this situation, so if this Exedy is going to warp another intermediate plate in 5k miles, then I'm just going to put an ACT in and hope for the best as far as lockout is concerned.
Anyone who suggests installation error should not even be on these forums. It worked fine for 5k . so that is not the problem.
Doesnt sound like dragging center plate. That would make clutch notchy for every shift.
When clutch is difficult in 1st amd reverse that is very clear the pressure plate is not releasing all the way. The first thing to check is to see if pedal in car is adjusted correctly. If it is then this likely means the new plates didnt last long mated to worn or warped (or both)surfaces. Or the old surfaces were surfaced (could be fly only and new floater/PP) and there was no consideration taken for removing material from metal simulates a wearing disc. As discs get thinner the pressure plate looses torque holding capacity due to geometry change. So when you resurface and remove .015 then you have to remove the same .015 from bottom of pp legs. Otherwise the .040 clutch life is starting at .025 clutch life. Difficult to explain clearly, but in short it sounds like clutch needed more than just new discs and it didnt get it.
Also quoting clutch life is pretty much stupid in itself. One could get 5000 miles and another 20,000 on exact same clutch with exact same power levels, and both got maximum life from clutch. peoples driving style varies that much. Its all about how many times clutch plates get slipped during its life.
Doesnt sound like dragging center plate. That would make clutch notchy for every shift.
When clutch is difficult in 1st amd reverse that is very clear the pressure plate is not releasing all the way. The first thing to check is to see if pedal in car is adjusted correctly. If it is then this likely means the new plates didnt last long mated to worn or warped (or both)surfaces. Or the old surfaces were surfaced (could be fly only and new floater/PP) and there was no consideration taken for removing material from metal simulates a wearing disc. As discs get thinner the pressure plate looses torque holding capacity due to geometry change. So when you resurface and remove .015 then you have to remove the same .015 from bottom of pp legs. Otherwise the .040 clutch life is starting at .025 clutch life. Difficult to explain clearly, but in short it sounds like clutch needed more than just new discs and it didnt get it.
Also quoting clutch life is pretty much stupid in itself. One could get 5000 miles and another 20,000 on exact same clutch with exact same power levels, and both got maximum life from clutch. peoples driving style varies that much. Its all about how many times clutch plates get slipped during its life.
Last edited by 94AWDcoupe; Sep 23, 2011 at 07:14 AM.
Anyone who suggests installation error should not even be on these forums. It worked fine for 5k . so that is not the problem.
Doesnt sound like dragging center plate. That would make clutch notchy for every shift.
When clutch is difficult in 1st amd reverse that is very clear the pressure plate is not releasing all the way. The first thing to check is to see if pedal in car is adjusted correctly. If it is then this likely means the new plates didnt last long mated to worn or warped (or both)surfaces. Or the old surfaces were surfaced (could be fly only and new floater/PP) and there was no consideration taken for removing material from metal simulates a wearing disc. As discs get thinner the pressure plate looses torque holding capacity due to geometry change. So when you resurface and remove .015 then you have to remove the same .015 from bottom of pp legs. Otherwise the .040 clutch life is starting at .025 clutch life. Difficult to explain clearly, but in short it sounds like clutch needed more than just new discs and it didnt get it.
Also quoting clutch life is pretty much stupid in itself. One could get 5000 miles and another 20,000 on exact same clutch with exact same power levels, and both got maximum life from clutch. peoples driving style varies that much. Its all about how many times clutch plates get slipped during its life.
Doesnt sound like dragging center plate. That would make clutch notchy for every shift.
When clutch is difficult in 1st amd reverse that is very clear the pressure plate is not releasing all the way. The first thing to check is to see if pedal in car is adjusted correctly. If it is then this likely means the new plates didnt last long mated to worn or warped (or both)surfaces. Or the old surfaces were surfaced (could be fly only and new floater/PP) and there was no consideration taken for removing material from metal simulates a wearing disc. As discs get thinner the pressure plate looses torque holding capacity due to geometry change. So when you resurface and remove .015 then you have to remove the same .015 from bottom of pp legs. Otherwise the .040 clutch life is starting at .025 clutch life. Difficult to explain clearly, but in short it sounds like clutch needed more than just new discs and it didnt get it.
Also quoting clutch life is pretty much stupid in itself. One could get 5000 miles and another 20,000 on exact same clutch with exact same power levels, and both got maximum life from clutch. peoples driving style varies that much. Its all about how many times clutch plates get slipped during its life.
I never suggested it was slipping. I suggested when plates wear down the geometry of clutch disengagement goes south. As the plates wear it takes more and more pressure plate spring travel to get disengaged correctly. It gets to the point the stock pedal travel is not enough for proper clutch function.
I am still unclear on which part jacks transmission is suggesting to polish...when you remove the twin disc, the outer most purple cover with the fingers (I was confident it was the pressure plate until someone told me other wise) contacts a floating plate. Any clarity would be great. Thanks
When you pull it out, sell it and buy the carbonetic pro blade regular or rebuild everything. Is this cost effective to rebuild again? that's your call, but there are other options such as act and carbonetic.
unfortunately, I have all the rebuild parts already...so at this point it is cost effective, just gona be another headache when the time comes to do it AGAIN. Besides your recommendation for a new/better setup, any input on jacks transmissions advice?
I can't say that I have used Jacks but I can tell you that TRE is the only one I know that shot peens the gearset for added strength. You will also get detailed work on the gears. IMO John is the best choice for evo transmissions. I'm not trying to start a flame fest, but send it there and if you have issues it won't be the trans. Just run a gl4 oil in the trans. Jacks transmission has a good article on clutch drag on their web page and tre has good reads in the faq
Last edited by Broham; Oct 26, 2011 at 12:20 PM.
Thread Starter
Joined: Aug 2011
Posts: 2,154
Likes: 5
From: Philadelphia, PA
I ended up just dealing with the drag. It's killing all of my synchros but I literally can't afford the down time, and the trans has 110k on it so it needs a rebuild anyway.