Clutch Work Questions...

[smac2K]

I have an ACT HDSS clutch kit that was installed in my 2001 just 15 months ago. Had it looked at and it is gone. I am being advised that I probably only need the disc replaced. The question is - Can we replace the ACT disc with an OEM disc?

Also, the shop said its time to replace the master cylinder as well...

Please help us and point us in the right direction!

Thanks,

Justin

[My_yella_s2k]

why would you replace the MC ? is it leaking?

and how the hell are you driving? you shouldn't have to keep replacing the clutch every 2 years...

[repiv]

Remember that the clutch kit that Hardtopguy once sold included the ACT HD PP, lightweight flywheel and OEM clutch disc and OEM TO bearing. That's what I currently have in my car. Only if you bought the whole kit from ACT, were you prompted to select the ACT clutch disc, which by the way, is a "reworked" OEM disc.
I would ask the same question Mike just did. My Vortech equipped S2000 went for 5 years (7 years total) before I went to the ACT. When I took out the old clutch, the disc still had more than a 1/3 left. The ACT has been in there for nearly 2 years and I'm hoping it will last longer than the original clutch would have.

But yes, you can use the OEM disc, however, if it's worn that quickly, you must be prepared to have to resurface or replace both the flywheel and the PP.
The master (or slave) clutch cylinders need to be replace only if they are leaking. These can be changed at any time and independent of a clutch job.

[reggie]

Justin and I go WAY back, and I plan to do the clutch job for him in my shop. I'm a DIY guy turned "pro" (meaning simply that I wrench everyday for a living). I specialize in BMW's, but am under the impression that a clutch on an S2K will be similar (i.e. PIA upper bolt(s)), clearance issues, etc.) I have access to AllData, but have yet to pull the info on this job.

Now, we have not physically looked at the clutch yet, so we're not 100% sure that the clutch is completely gone. It JUST started to slip on him yesterday, and only in high gear at speed (right j?). I just got to drive it in a parking lot, and from a dead stop it seemed like it still gripped okay, BUT the friction point is WAY at the top of the pedal. My hope is that the flywheel/pressure plate are okay. He has stopped driving it to avoid any further damage. I will try to have it up on the rack early next week to get a better handle on what we have for sure.

My questions are:

Has anyone else seen a clutch on one of these cars slip WITHOUT the disc being trashed? i.e. some sort of glazing, etc?

Is there anything that may not be covered by AllData that I should know?

I read somewhere to watch the knock sensor, as it is easily bumped. anything else like this?

Any special tools? I have a good assortment of wobbles/swivels/extensions, etc.

How long to throw-out bearings last on these cars? My experience with BMW's is that they come due well before the clutch disc. Should we look at replacing a 25K TB as preventative maintenance?

The goal is to do this as inexpensive as possible without half-ass, do-it-again-in-a-year results.

Thank you to anyone that replies. I have heard nothing but great things about this community!


Reggie

[repiv]

It is commonly reported that the S2000 clutch parts can get glazed easily if revs are mis-matched badly when shifting and from clutch dumps done poorly. Once glazed, it is not always a sure thing that the clutch can "come back". It al depends on how badly it was glazed. Many have reported that the first glazing can be recovered from if the car is driven "normally" for a while. I have seen posts from owners who have glazed their clutches with only a couple thousand miles on the car. Flywheels can become heat checked easily.
I'm not familiar with AllData, so can't comment on what information is gives. The knock sensor is easily cracked or broken due to the long extension being used when under load, the extension bows. The remedy for this is to disassemble the intake manifold brace so you can get a more direct shot at the starter bolt. Another key point is to not confuse the lower starter bolt with the upper one. It's the upper one that must come out before the tranny can be pulled away from the engine.
TO bearings can last well into 100K miles, but it's such a low cost item, it's best to just replace it when doing a clutch job. Just make sure the bearing is well lubricated according to the instructions.
Another thing that has plagued clutch instalers on this car. The release fork must be completely and evenly seated into its spring holder. Without this, the tranny always falls about 1/4" short of mating up with the back of the engine. Speaking of the release fork, it's a good practice to clean off any pitting or corrosion from the socket, in addition to the ball of the slave cylinder plunger. The pits that can form in this area can make a new clutch job seem like it was for nothing a very short time later. The plunger also has a tendency to slowly ooze out. Don't let it go too far or you'll lose fluid and pull in air. Not a bad idea to bleed the clutch fluid after everything is put back together.
Another common thing is when removing the shift stick from the console. That white plastic ring can easily be broken. The retainer clips can't be seen when trying to remove the ring. You have to blindly push a thin object down into the slot to release each of the 3 clips.
Being that you are an experienced mechanic, you likely don't need anything further, but I do have fairly complete "How To's" on the clutch job and master cylinder replacement, with lots of pictures in the How To section of this forum.

[reggie]

So a glazed clutch IS a possibility, and doing some light driving could potentially clear this issue up? That is interesting, and somewhat logical. Justin did mention something about a burning clutch smell when he recently backed the car up his steep driveway. If the symptoms introduced themselves directly after this, then I'd say this is a plausible scenario. We'll keep our fingers crossed.

Ahh, the amount of headaches you have potentially just saved me (in reference to the tip/tricks if/when I do pull the transmission)!!

Thank you so much. I will report back once we start to figure things out further.

[Rocketman]

So a glazed clutch IS a possibility, and doing some light driving could potentially clear this issue up? That is interesting, and somewhat logical. Justin did mention something about a burning clutch smell when he recently backed the car up his steep driveway. If the symptoms introduced themselves directly after this, then I'd say this is a plausible scenario. We'll keep our fingers crossed.

Ahh, the amount of headaches you have potentially just saved me (in reference to the tip/tricks if/when I do pull the transmission)!!

Thank you so much. I will report back once we start to figure things out further.You might want to PM trackit for additional tips. He is the master S2000 mechanic here in Houston and has done several clutch R&Rs.

[repiv]

Justin did mention something about a burning clutch smell when he recently backed the car up his steep driveway.

That would do it. I've often backed up my driveway with the cat pee smell thereafter. It goes away the next time the car is driven. Sometimes, the smell can stick around for up to a week.

[reggie]

That would do it. I've often backed up my driveway with the cat pee smell thereafter. It goes away the next time the car is driven. Sometimes, the smell can stick around for up to a week.

What about the friction point being at the top of the pedal travel? Is this normal on an S2K, or is there any pedal adjustment?

I've always used the clutch engage/dis-engage point in the pedal travel to "guestimate" the thickness/continued lifespan of a clutch.

Thanks again!

[darkside]

There is an adjustment point.

[repiv]

What about the friction point being at the top of the pedal travel? Is this normal on an S2K, or is there any pedal adjustment?

I've always used the clutch engage/dis-engage point in the pedal travel to "guestimate" the thickness/continued lifespan of a clutch.

Thanks again!

No, the friction point should not be that high. Something is not right. It should begin to grab about 2.0" off the floor and be completely engaged with about 2.0" of play at the top. Was it always that high or did it just happen after the clutch was glazed? If it's always been that high, then I would suggest that the clutch disc is, in fact worn down badly OR, someone else has messed with the pedal adjustment.
I would first do a clutch fluid change and bleed to eliminate that as a possible source of the problem. Then, if the friction point is still high, there is a pedal rod adjustment. If you look near the pivot point of the pedal, you will see a rod going into the firewall. At the pedal end of this rod, you will see a locknut. Undo the locknut and twist the rod 1 turn at a time, lock it down and test. You may need to reverse or go further. This is but a temporary solution to a possibly bigger problem, of which the solution may still be a clutch job.

[smac2K]

Let me chime in here if I may...

As far as the "friction" point goes...Since the first minute I had the new clutch put in it has been that high. I literally push the clutch in NO further than 2" probably not even that much...the rest of the way to the floor does nothing but make my leg hurt...It's extremely "springy" and I rarely keep the clutch in while I am stopped...

I have done a couple sets of donuts during the life of this clutch...literally...maybe 3...I do like to leave stop lights quick sometimes and sometimes I VTEC to get around traffice. Most of the 25K-30K miles have been interstate travel for work and vacation. I have become very good at rev-matching (as I have been told :shrug:) and I try my best to not ride the clutch.

:popcorn:

[repiv]

Let me chime in here if I may...

As far as the "friction" point goes...Since the first minute I had the new clutch put in it has been that high. I literally push the clutch in NO further than 2" probably not even that much...the rest of the way to the floor does nothing but make my leg hurt...It's extremely "springy" and I rarely keep the clutch in while I am stopped...

I have done a couple sets of donuts during the life of this clutch...literally...maybe 3...I do like to leave stop lights quick sometimes and sometimes I VTEC to get around traffice. Most of the 25K-30K miles have been interstate travel for work and vacation. I have become very good at rev-matching (as I have been told :shrug:) and I try my best to not ride the clutch.

:popcorn:

A friction point that high leads me to believe that your clutch has never fully engaged since the new clutch went in. That is to say, your clutch has most likely been slipping all the time to some degree or another, thus making it extremely easy to make it slip even more under power and glaze it. If it's otherwise working to your satisfaction, I would strongly suggest that you ........
1. Do the fluid bleed to make sure all air is out of the system.
2. Do the clutch pedal rod adjustment so that you have the recommended amount of play both at the top and the bottom of the pedal stroke. Only when you have the prescribed amount of free play at the top, can you be certain that the clutch is fully engaged.

[smac2K]

Will do.........................

REGGIE!!!!!! :above:

:lol:

[reggie]

Okay, I drove the car back to my shop today, and under what I call "normal" driving conditions there was no slipping. It was an easy drive, so no passing, and I accelerate hard.

I was able to make the clutch slip with heavy throttle input, especially in a higher gear at speed.

I put took a look at the pedal, and it does not seem to need adjusting. There is an inch or so of play at the top, so I would think that the hydraulics have fully disengaged (engaging the pressure plate) before the pedal has completed travel. I can physically see the back of the plunger seating in the clutch master before the clutch pedal reaches the stop/switch.

I have not flushed the fluid yet, and it definitely does need it. The clutch master is seeping what appears to be black grease at the input. Should there be a boot here?

I also removed the clutch slave cylinder from the bell housing to see if there was any way to inspect the clutch thickness. I noted that there is pressure between the mounted slave and the pressure plate (as there should be), but there did not seem to be enough pressure to partially disengage the clutch. (I reinstalled it by hand).

I will go ahead and flush the fluid, then test drive. I am going to leave the pedal alone for now, as it is definitely allowing the clutch to fully engage.

Regardless of the pedal position, I can now say that the friction point is at the rear of the clutch master's length of "functional" travel (if that makes sense).

[reggie]

I should also clarify my previous statement about the friction point being at the back of "pedal travel". This is what it felt like, but not "technically" true.

I was actually referring to "clutch hydraulic travel"....the part that I can physically feel in my leg. I did not feel/realize that there was play at the top of the pedal after the pressure of the pressure plate was released.

Sorry Justin, this isn't necessarily "good" news.

The fluid is changed, and getting ready to go drive. We'll cross our fingers.

Reggie

[repiv]

The clutch master is seeping what appears to be black grease at the input. Should there be a boot here?

Regardless of the pedal position, I can now say that the friction point is at the rear of the clutch master's length of "functional" travel (if that makes sense).

There is no "boot" where the pedal rod goes into the master cylinder. It should be completely dry. It would appear as though the master cylinder is leaking.

Using those terms to describe the friction point is atypical and somewhat confusing. The service manual speaks of it in terms of pedal travel. Pedal height is 189 mm (from the top surface of the foot pad to the floor) when at rest (not pushing on the pedal). Pedal stroke should be 115 - 125 mm (from rest to fully depressed).
As you lift up off the floor, the friction point (where the clutch begins to engage and move the car) should be about an inch to no more than 2 inches from the floor and be fully engaged with about 1" of free play at the top.
If it still slips under heavy throttle in a higher gear, the clutch is most likely still glazed. If it doesn't come back, then a replacement may be in order. However, give it a week or so of "normal driving". An ACT HD PP should not be slipping, even if the car is FI. It certainly shouldn't be slipping on a NA S2000.

[repiv]

I should also clarify my previous statement about the friction point being at the back of "pedal travel". This is what it felt like, but not "technically" true.

I was actually referring to "clutch hydraulic travel"....the part that I can physically feel in my leg. I did not feel/realize that there was play at the top of the pedal after the pressure of the pressure plate was released.

Sorry Justin, this isn't necessarily "good" news.

The fluid is changed, and getting ready to go drive. We'll cross our fingers.

Reggie

If you don't feel any free play at the top of the pedal travel, then you can't be sure the clutch is ever fully engaged. It may be constantly being semi-disengaged, which would make it prone to slippage most of the time.

[smac2K]

Dave you are NOT going to believe this - BUT THE FLUID CHANGE PROCESS FIXED IT!!!!!!!!!!!!!!!!!!!!!!

:D:D:D:D:D:D You've never had that many smilies in your forum before I bet ;)

Anyway, Reggie will explain what I miss, but basically the fluid was black and had chunky stuff in it...He also removed the master cylinder (I believe) and re-installed it...

I have no knowledge or anything, but we both tried for over an hour to re-create the symptoms and it JUST WON'T DO IT!!!!!!!!!!!!!!

Thank you to both Reggie and you for talking this out and for your help :bow:

Justin

[repiv]

Glad that did it. Fluid change and flush has always been my first suggestion. However, keep an eye on that small seapage where the pedal rod goes into the the master cylinder. Wipe it dry and check it again every few days. If it continues to get wet, a new MC will be the final answer.

[smac2K]

Another question... The S2000 has a LSD, right? When Reggie had it on the lift he noticed the rear wheels did NOT turn in the opposite direction, and that they both went in the same direction! Do I have another problem????

[repiv]

Another question... The S2000 has a LSD, right? When Reggie had it on the lift he noticed the rear wheels did NOT turn in the opposite direction, and that they both went in the same direction! Do I have another problem????

That is unusual. The wheels should spin in opposite directions. Try it in gear and in neutral. Yes, we have a Torsen LSD. It works via a system of worm gears and NOT clutch packs.

[smac2K]

I'll tell Reggie, and will try it ASAP...:yep:

I was also told that it is not a "normal" procedure to change clutch fluid with a clutch change...kinda like not changin brake fluid when changing pads...:yep:

I'm so freakin happy right now I can't see straight :willynilly:

[repiv]

I'll tell Reggie, and will try it ASAP...:yep:

I was also told that it is not a "normal" procedure to change clutch fluid with a clutch change...kinda like not changin brake fluid when changing pads...:yep:

I'm so freakin happy right now I can't see straight :willynilly:

It kinda depends on how old and contaminated the fluid is. It shouldn't necessarily be dependent upon coinciding with a clutch job but as I may have indicated, doing a clutch can cause air to infiltrate the system and/or some fluid to be lost during the process. It's not a tough thing to do and doing it after a clutch job can help to eliminate it as a possible source of any problem that may arise.
Certainly, if the fluid is fairly new and in good condition, there is no need to do anything at a clutch job, but as you've discovered in your case, the fluid was pretty bad and if a fluid change is part of the job, at the very least, its condition would have been seen. Better to start a fluid change and then decide that it's not needed than to not have it on the "to do" list and finding out it was a pivotal step.

[smac2K]

Thank you, Thank you, Thank you....AGAIN...

[reggie]

Another question... The S2000 has a LSD, right? When Reggie had it on the lift he noticed the rear wheels did NOT turn in the opposite direction, and that they both went in the same direction! Do I have another problem????

No, no, you got it turned around. The rear wheels on your car DO turn the OPPOSITE direction. On a traditional LSD (like my old BMW's use), this is is what an open diff does. On our cars both rear wheels turning in the same direction is the fast/easy way to determine if the car is fitted with a limited slip unit.

I figured the S2000 would have some sort of locking diff, I just have no experience with a torsen diff. That is interesting. I will have to look that up.

[repiv]

Mystery solved. LSD is good.:thumbup:

[reggie]

I'll tell Reggie, and will try it ASAP...:yep:

I was also told that it is not a "normal" procedure to change clutch fluid with a clutch change...kinda like not changin brake fluid when changing pads...:yep:

I'm so freakin happy right now I can't see straight :willynilly:

I'm super glad this has worked out. I didn't want to put a clutch in your car any more than you wanted to pay for it!!:D

All I mean by the clutch fluid not being a normal procedure, is that it is a separate labor/service item in a shop. YES, a good tech should advise you to change the fluid when you do a clutch, but it would typically be a charge over an above the clutch R&R.

I usually pull the clutch slave cylinder from the bell housing, but leave the hydraulics connected when I do a clutch job. I just hang it back out of the way (if/when possible). This way I don't get air in the lines.

[reggie]

Using those terms to describe the friction point is atypical and somewhat confusing


Agreed. This was simply a case of my inexperience. My old cars have such a light clutch that it is hard to decipher between the end of the hydraulics and the pedal return spring. After releasing the heavy pressure plate, I my leg simply didn't detect further pedal travel....again my mistake.

Thanks again for all of your help!! You saved both Justin and I alot of headaches.

[repiv]

I usually pull the clutch slave cylinder from the bell housing, but leave the hydraulics connected when I do a clutch job. I just hang it back out of the way (if/when possible). This way I don't get air in the lines.
That's the way I did it, too. :thumbup: In my case, I found that little slave cylinder plunger kept creeping out and whenever I bumped it, it would try to ooze out of the cylinder. I had to keep pushing it back it to prevent losing fluid and getting air in.



Thanks again for all of your help!! You saved both Justin and I alot of headaches.

I'm really glad it turned out this way. I hate to see people expending money and effort (for the tech) to do something unnecessary. Currently, there are two threads going on in the "other" forum where, after a clutch job, the pedal can't be pushed. A clutch job isn't brain surgery but it does entail doing things according to a plan. Nobody has clued in yet that the problem is that the release fork wasn't fully pulled out at the moment the transmission was mated to the back of the engine and the fork is pinched slightly lop-sided between two immovable parts of the clutch assembly. All they have to do is to separate the tranny from the engine by just a few mm and clear the fork and try again. But then, I don't post over there. They'll figure it out eventually. :flames:

[smac2K]

Well, bad news...the "fix" wore off after a few thousand miles and we even replaced both master and slave cylinders...

All that said, Reggie got to learn how to do a S2000 Clutch job...

here are the pics that he sent me after he pulled it apart...

Here is the new disc on top of your old disc. Its over twice as thick:

http://f838.mail.yahoo.com/ya/download?mid=1%5f359572%5fAE9Vk0UAAFz2SjFARwcAWlfY 8k4&pid=2&fid=Inbox&inline=1&stationery=1

Here you can see the wear indicating grooves on the new disc:
http://f838.mail.yahoo.com/ya/download?mid=1%5f359572%5fAE9Vk0UAAFz2SjFARwcAWlfY 8k4&pid=3&fid=Inbox&inline=1&stationery=1

Here you can see that these grooves are worn completely down and the surface is down to the first set of rivets
http://f838.mail.yahoo.com/ya/download?mid=1%5f359572%5fAE9Vk0UAAFz2SjFARwcAWlfY 8k4&pid=4&fid=Inbox&inline=1&stationery=1

The pressure plate has been HOT. It probably should be replaced:

http://f838.mail.yahoo.com/ya/download?mid=1%5f359572%5fAE9Vk0UAAFz2SjFARwcAWlfY 8k4&pid=5&fid=Inbox&inline=1&stationery=1

[repiv]

The pictures don't work ...................... [x]

I'd like to go back to the post where you indicated the clutch friction point was very high on the pedal travel and re-iterate that this is not normal. A high friction point like that indicates that there is great likelihood of clutch slippage under moderate to hard use. This slippage will wear down a clutch rapidly. Now, if you got the friction point resolved, then I'm curious as to just how hard you drive it, how much launching you do and how well you rev match both downshifts and upshifts.
Next, I don't recall seeing any posts about whether or not the flywheel was resurfaced or if the PP was resurfaced or if both were replaced or just re-used as they were. Any imperfections on a used flywheel or PP will grind the new disc down to nothing very quickly.
Did I ever cover the part about properly packing the TO bearing with grease and lubing the release fork fingers? How about polishing the release fork socket and the slave cylinder plunger ball and greasing both? If these were overlooked, incorrect clutch take up and positioning would be an issue, all contributing to advanced clutch wear.

[smac2K]

The friction point of the pedal was at the top from the very first instance that I picked it up.

I will say that I am pretty sure that I rev match pretty good, and have confirmation by others...

I do alot of interstate driving, but there are the occasional launches and "blips" as I get the car going...(nice exhaust and fujita intake)

The flywheel was resurfaced last time...The pressure plate was brand new in the ACT clutch kit..

I will let Reggie know about the grease and lubing he should do when putting the new one in...

The pictures...well, I'll figure that out...

[repiv]

The friction point of the pedal was at the top from the very first instance that I picked it up.
This is still not a good thing. If everything else has been taken care of, a pedal rod adjustment is required. If the rod has ever been adjusted at a time when fluid was old or low or when something else was not right, then once things are "right", the pedal rod needs to be "UNadjusted". That's usually what happens when people notice the friction point getting lower and lower as the fluid gets old or low or as the clutch wears too much. They adjust the rod to bring the friction point back up. When the fluid is changed or when the clutch work has been done, the friction point then becomes too high. An adjustment made due to an existing deficiency must be reversed when that deficiency is taken care of.
Do you recall ever doing a pedal rod adjustment? A previous owner perhaps?

[smac2K]

Well, I know for SURE that I have never done it...:laugh:

When the ACT was put in there is a chance that they did, but didn't tell me anything...:rolleyes:

[smac2K]

So, should Reggie adjust the pedal so the friction point is closer to the firewall?

[repiv]

So, should Reggie adjust the pedal so the friction point is closer to the firewall?
Absolutely! BUT, make sure the fluid is good and all other considerations are taken care of (proper greasing and polishing of stuff that need it). You should have at least 1.5" free play at the bottom and about the same at the top.

[Scooterboy]

Justin, I can make you such a deal on what I have posted.....

[smac2K]

Justin, I can make you such a deal on what I have posted.....

I saw that, but I think my driving skills require an OEM clutch...I would've contacted you first :yep: If I wanted to do that to myself again...:laugh:

[repiv]

I saw that, but I think my driving skills require an OEM clutch.
The premise is that a stronger PP would help to make the clutch last longer, given all kinds of drivng styles. If you're clutch has been wearing prematurely due to slipping, a lighter PP like the OEM, would cause even faster wear. I think part of the problem (and the main one) in your case, was not the actual clutch parts themselves, but rather, the location of the friction point. If it were me, I'd stay with the HD PP and make sure the pedal take up is set up properly. In any case, so long as the friction point is where it should be, with the correct amount of free play at each end, both the OEM and the ACT should work well for you. The ACT would just work better and feel better.