6 months diagnosing the issue and can't find the answer.

Received rebuilt motor back from well known builder on this forum. Builder also installed new exedy twin disc clutch onto the motor.

Installed the motor in the car, and tranny won't snap on. After a couple of try, pull the motor back out and check with clutch alignment tool. Clutch not aligned. Realign with clutch tool, and yay! tranny snap on.

Brought the car to NeptuneSpeed for initial tune with the PowerFC, this is for the break in period.

Then here comes the issue:
It is hard to shift into 1st and reverse gear. At the time, I had new master, new slave, new clutch, rebuilt motor, same tranny before ( no issue).

1) Bled the system, didn't help. Look through peep hole of tranny, one of the throw out bearing hand broke. Yay! Found the issue, replace with new throw bearing. Also replace new pilot bearing with SST tool. Did not fix the 1st and reverse gear issue.

2)So maybe the clutch disc was install backward. Remove tranny again and disassemble the twin disk. Disc installed correctly, pressure plate fins still new, no bent. Pressure plate ring still good, no bent. Reinstalled and torque to exedy specs.

3)So maybe it's a tranny issue. Sent tranny to Anaheim Gear in Anaheim, CA for rebuilt. Anaheim open up the tranny and said there's nothing wrong with it. $250 labor to reassemble. So I end up just doing a basic rebuilt anyway. Got the tranny back, installed with another new pilot bearing, did not fix the 1st and reverse issue.

4) Took the car to Dave Lemon at Mazdatrix in Long Beach, Ca. Dave test the car, it's not your pilot bearing or your clutch. If you did all of the above already, it's either the gear box or the hydraulic system. Purchase another set of new clutch master and clutch slave, and idemitsu tranny fluid. Installed and change fluid, problem still there.

5) Took the car back to Pat at Anaheim Gear. Pat test the car and goes: It's either hydraulic or the clutch. When the engine is off, you can shift the tranny smoothly. When engine is on, the clutch power is being transfer to the tranny because it is not completely disengage. 2nd, 3rd, 4th, and 5th no issue because the car is already moving. 1st and Reverse, car is at dead stop, hence you have to push harder when the clutch is not completely disengage. Yes, I am wearing out my synchros if this problem continue.

Other things I have done: Clutch pedal free play is about half an inch. Rod is extended all the way out to give it enough throw. There is no air in the hydraulic system. Installed another used clutch fork from another tranny, nothing wrong with the first one.

6) In the process of borrowing my friend FD ACT clutch and installing it to see if the problem will go away.

7) Any feedback and help from the forum will be appreciated, thank you guys!

Please excuse my grammatical error, writing is not my strong point.

 

I'm having this exact same problem with a recent Exedy clutch installation, but the only problem is reverse. 1st may be a LITTLE notchy, but totally usable... but reverse is almost impossible once the car is running. It worked fine for about a week after the installation.

P

 

Sounds like you found the issue, unfortunately in step 5. The twin-disk clutch probably isn't quite the right dimension. Alternative to step 6 is to modify the clutch slave piston. Shorten it enough so that the fork disengages. Should be easier than swapping the clutch out.

 

I've not heard of Exedy clutches requiring anything modified, but I have heard of clutch slave cylinders failing or degrading, so maybe the Exedy just exposes something weak?

 

Rxspeed16, i somehow get what youre trying to say. I examined the pressure plate ring and it only have a certain distance of travel. So if i were to allow the clutch fork to move back more where it meets with the slave, that would push the throwout bearing forward and the pressure plate ring will be loose.

Plus im to find out what the real problem is and whats wrong with the clutch.

This is a popular clutch, im surprised i havent solved this issue yet even after i changed out everything with the exception of a new clutch fork.

Looking for more feedbacks.

Thank you

 

New and weird discovery:

1) Start the engine with 1st gear in and kept clutch disengage. With the pedal depress, kept changing gear from 1st to neutral then back to 1st, smooth for about 50 times. After that, I felt it would get hard.

2) Start the engine at neutral with the pedal still depress. Smooth going from neutral to 1st, after about 6-10 times, it would get hard.

3) Start the engine at neutral and let go of the clutch pedal. Disengage and go 1st gear, gets hard right away.

Conclusion:
Every time the engine is running. If I let the clutch engage back in neutral and disengage to go into 1st gear, it would get hard right away.

Hmm thoughts anyone?? I have a feeling if I change to the single ACT clutch tomorrow, the problem will go away. Update more tomorrow.

 

Maybe the fingers on the pressure plate aren't releasing the clutch discs entirely. My buddies RX-8 had an issue very similar to this and we changed his fork, master, slave, adjusted the pedal and bled like two bottles of brake fluid through it and I was getting MASSIVE movement from the clutch slave, yet it still wasn't fully disengaging. Changed the pressure plate, and all was well.

 

Given that it's two people with a similar problem related to recently installed exedy clutches, I wonder if there's a defective batch?

My car is going up to IRP for s look this week.

OP: where did you purchase the exedy from?

 

Just as I thought. Removed the exedy twin disc and installed the ACT clutch, shifting is smooth now through all gear.

How old is the exedy twin clutch? I purchased it in October, 2011 from Nick at THMotorsports. How much mileage has it seen? Less than 1500miles, all mileage from motor break-in period. Why it took me 4yrs? Well, you would see this story in a new thread if the person who caused me all this problem does not take responsibility.

I should be happy but I am more devastated when I found the possible caused for the 1st and reverse gear issue.

1) Here's an overview and pics of the clutch during removal. After the clutch was removed, I inspected it and notice a hair line crack on the back of the first mid plate. Now, this crack was not present about two months ago when I first inspected it.

Full photos




2) Installed the ACT flywheel, clutch, and pressure plate. Use clutch alignment tool (pic). I was about to torque the ACT pressure plate and stop when I remember what my friend said. He said, "When I finished building a motor or doing a clutch job, Yoshi at NeptuneSpeed would make me double check the tension bolt torque spec. Just to make sure it's not loose. If it is too loose, then it might cause problem with the clutch." When he first told me that initially, my attitude was like, the guy who built my engine is an excellent engine builder on the forum, i'm sure he wouldn't make that mistake. Nonetheless, I was like what the heck. I have easy access to it, might as well check it. So I disassemble the ACT clutch and flywheel again.




3) Here comes the devastation. Engine has seen less than 1500miles, all break-in mileage on a PFC. This is the 2nd motor I received from the builder through a warranty. Warranty motor arrived back in March, 2014. So I checked tension bolt #1 and #2, I could turn it with my hand using the socket!!! So I torqued all the bolt to 20 ft/lb and found #3,#5,#8,#9,#12,#13,#15, and #16 were all under 20ft/lb. Especially, #15 and #16, they were really loose (can't turn with my hand though). Overall, #1 through #16 were far off from 30 ft/lb, only #17 & #18 were close to 30ft/lb.

(after everything torque to 20ft/lb)

In conclusion, my problem is fixed with the ACT clutch. I will be putting back the exedy twin disc soon to confirm that the loosen tension bolts caused the 1st and reverse gear issue. The hair line crack on the 1st mid plate was not there before, the loosen tension bolts might have crack it as well. Also time to send an email to the engine builder.

More update after I reinstall the exedy twin disc in the upcoming weeks.

 

Hmmm, mine was purchased from THMotorsports about two months ago, and on the car for about a month, installed by Speed1, who screwed some other things up.

It's at IRP right now, we'll see what Ihor says. I'm wondering if they are either bad batch or fakes, or just misinstalled.

 

If I had to guess I'd say twin plates just need a little more length to pull the clutch off the fly wheel.

So worn fork or a little air in the system and you have issues.

Can't think how loose tension bolts would cause clutch issues UNLESS they were so loose the flywheel was literally moving in and out

 

Clarification on my recent post. My 1st motor detonated in Sept. 2012 due to a bad based map that I received. It was a computer mistake, so I ended up receiving a stock base map for my motor. Builder took ownership and rebuilt the motor. For this recent tension bolt and other minor error, builder and I will work together. And if the motor needs to be rebuild again, then builder will redo it.

Fritz, I don't think it's a hydraulic issue or the clutch fork. Because on my first motor, it was the same clutch fork and hydraulic, and I did not have this issue. Now that the tension bolts are torque to 30ft/lb, I will have answer once I reinstall the exedy twin disc this weekend. Hopefully, that hair line crack on the plate (picture in above post) will not alter the result.

 

I've had a few fake exedy clutches come through over the years, but as I recall they were stock replacements for rx8s and all were purchased by the customer elsewhere from various sources. Issues were premature wear, throwout bearing failures, and vibrations. I had one Cusco twin disk which is a rebadged exedy that wouldn't disengage all the way. I source my edexy twin disks direct so I know the ones I sell are good. There are a lot of counterfeit parts these days. I'll post results when it is apart.

 

Is that an actual crack? From the photo it appears to be friction material transfer. Try to scrub it off in that spot with a green scotch brite pad and see if it comes off. I'm magnifying all the way and just can't see a crack...
Also I would think that with the low miles, the only way there could actually be a crack there, is material defect. It's not like you overheated it or anything.

 

We install at least a dozen of these every year and have never had any problems, that being said here is what I found with a quick search on the web. This is the EVO twin disk but the problem is the same. Exedy Twin Disk Clutch WARNING ? Jacks Transmissions

Exedy Twin Disk Clutch WARNING


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!

 

I actually had the same exact issue with an evo clutch. Makes sense because the fd uses the same clutch as some evos. Customer sourced the clutch himself so he ended up exchanging it for a new one. The replacement seemed fine so we never had to look into it further. Maybe there is a a broad manufacturing tolerance. I'm working on Peter's car right now and will post what I find.

 

It is a crack because I ran my finger nail through it and felt it. Hopefully I could just called exedy and order another plate. Is there a way to check the authenticity of the clutch? Because it would suck if I replace the plate and it ended up being a fake one to begin with.

 

For reference, here is my new triple disk next to my twin disk (to the right) It should have all the paint marking from the balancing process, cover should have a 4 or 5 character black number, exedy logo etc.. Also an identifier on the back on the flywheel. Problem is that any/all of these can be faked, however Exedy should be able to confirm the authenticity.




Twin disk installed

 

Update:

Banzai-Racing, I do have those blue paint line and white marking. Also, I did remember those number on the flywheel before I wiped it off with brake cleaner.

Nothing better to do on Christmas day then to put back that Exedy Twin Disc. The 1st and reverse gear is better. Better as in I can lightly shove it in vs before where I have to shove it. I think the problem has not went away completely due to the hairline crack on the pressure plate (part # PP02). Also, I forgot to polish the intermediate plate (part # IM01) and the arm on the flywheel as mention by Banzai-Racing.

*sigh* I lost count, but it's probably my 6th or 7th time taking the tranny off already since chasing this issue.

More update after I order a new pressure plate and install it.

Banzai-Racing, just to confirm. Polishing is for the contact point between #3 and #8? Reference picture below.

 

Polishing the clutch basket area didn't help on this car. Clutch seemed to be assembled properly, only thing I noticed was slightly uneven heat marks on the pressure plate and the input shaft was banged up from a careless previous installation. Hydraulics all check out fine and clutch rod is adjusted properly. Got to look into this further.