I'm having a strange feeling in my clutch pedal - but it only occurs at high RPM shifts under WOT. The car runs/shifts fine, but under very hard acceleration, when I push the clutch pedal in to shift, it feels as though it's not all there. It's almost as though as the RPM's go up, the amount needed to press the clutch in reduces. Recently adding some extra brake fluid has helped, but I can still feel it (this is a 6 speed manual, btw) on a 2001 360 coupe. When this originally happened, I thought my clutch was going, but it doesn't seem like this is the case (car shows no signs of any problems with the clutch, etc.) Okay, so I called FNA last week and asked some questions. During the conversation, I was told that the clutch has a bit of a "cone" shape to it (for lack of a better word) and that the flywheel has a slight bevel which receives this. My understanding was that at high RPM's, the clutch disc flexes out into that bevel in the flywheel and this helps a little bit in order to produce better grip as the disc flexes into the bevel - some sort of very cool F1 tech stuff I guess. This being the case, I would gather that at high RPM's, this flex could alter the relation of the pressure plate against the disc to a small degree - and perhaps this is what I'm feeling in the clutch pedal. But I'm not sure. I suppose with an F1, you would never feel this, but like I say, this is a 6 speed manual. The other night, I checked and I was about half low on brake fluid, so I added some. This seemed to have helped matters and now the pedal does this "going away somewhat at high RPM's" much less noticeably that it did before - but it's still there. This weekend, time permitting, I'm going to bleed the slave cylinder (assuming I can find it! and see if perhaps I have some air in the line and/or if that may make some difference. Anyway, does any one have any comments on this? Has anyone else experienced this same sort of feeling in their pedal? Is it indicative of anything specific or just a byproduct of how the clutch design feels during high RPM shifts with a manual gear box (vs. the F1, which wouldn't feel it so much). Would air in the line produce this result? As I say, the car runs fine and there is no indication that anything is wrong with the clutch - other than the slight change in pedal feel at very high RPM shifts. It's just a little disconcerting to have the feel of the pedal alter slightly during high RPM vs. lower RPM shifts. When I say lower RPM, I mean any relatively brisk shift up to 7k or 8K, while the higher RPM shift would be defined as full throttle, hard run, "getting on it like your life depends on the next gear" shifts at redline under full throttle (you know what I mean Any comments, suggestions... tips on bleeding the slave cylinder? Ray PS. In thinking about this further, I'm wondering if air in the system might allow for the T/O bearing assembly (i.e. slave cylinder) to give a little under high RPM rotational loads on the clutch/PP/flywheel assembly. That might mimic depressing the pedal a bit (since air would compress more readily than fluid) if it did in fact exert pressure against the T/O. I'm going to bleed the system shortly here and see if that makes any difference and/or if there is any air in the line.
Hi Ray, I P.M'd the location of the bleed nipple. If the lines have air in them you will feel the clutch release later than usual. If it releases in the same spot then you probably have another problem. For example, if it started pulling(car starts moving) at 1.5" release yesterday and then went to 2.0" today then you have air in the system. Or a very quick wearing clutch. I noticed this when bleeding my clutch, at first I thought I had it and the pedal would release about 1/2 way. So I thought I would bleed it some more. After working with it for about 30 minutes it started pulling at 1". Good luck with it! Scott
A word of caution- The bleed nipple housing is very poorly designed and easy to damage when re tightening- Ferrari updated the part. On my car it gave way after a previous attempt to bleed it. This let all the fluid out and air in. He managed to bleed it at the gearbox end but it wasnt changing gear well and so also ended up having to bleed the master cylinder (accessed from behind the front cover in the bonnet (removed by lots of little allen screws. As there is no bleed nipple on the master he ended up loosening the hydraulic pipe and pumping the pedal.
Thanks for the tips. The engage and release points seem okay - about the same as always. It's only under high RPM's that the pedal feels as though it's already pushed in 50% when you go to push it. It's odd, but my friend's car does the same thing. It's almost like at high RPM's something is causing it, which makes no sense to me. It seems that in order for that to happen, the pressure plate would have to be opening its grip on the clutch disc a bit. The whole thing just seems very odd. I did bleed the slave cylinder today, but no major changes. Things did improve a little bit when I added more fluid to the master cylinder, but it still occurs here and there under high RPM's. I did not bleed the master cylinder, although on most cars there is no need to do that typically. I haven't looked at the setup too closely however on the 360. I may take another look later and/or check the shop manual. When you say they bled the master, what exactly did they do? Is there a bleeder nipple on the master cylinder? I was only checking the fluid level while up front. Ray
The master cylinder doesnt have a bleed nipple. Because the car had lost all of its clutch fluid, it took in lots of air. My mechanic renewed the fluid but the clutch still wasnt right. He then explained that becasue the master cylinder is higher than the bleed nipple air gets stuck in the master cyl. To bleed this the mechanic loosened the hydraulic pipe union and had me pump the clutch 4 times. We did this 3 times and then topped up and tightened the union. The problem I had with my car was different to yours but its worth having a go at this if you think that your cylinder has taken in any air.
Ray, I had the exact same problem w/ my 99 6 speed. It only happened at the high RPM - felt like the clutch pedal got dropped to the floor a bit. Bleeding the entire system did not help at all. I think it turned out to be the warped flywheel and got fixed when resurfaced. Brian did all the work so you may want to ask him what he did. Or I can look for my repair receipt for the actual work description. Chris
Hi Chris, I would like to see a list of what was done (maybe you can PM me or post a scan or something). In speaking with FNA, my understanding is that you cannot resurface the flywheel, because it has a bevel to it. I could mistaken, but FNA was pretty clear on the point of "you don't resurface the flywheel". I haven't torn into mine yet however. Frankly, I still don't have a clear understanding of what is taking place inside at high RPM's to produce this result. I've heard from several other people who have the same issue, so it must be relatively common. I don't know if it's indicative of a part breaking or what, but I can't quite figure out what is going on inside. It is almost like the pressure plate is flexing open at high RPM's and taking the T/O bearing with it.. that's the only thing I can picture that would cause the pedal to feel like it's not there. Since the pedal pressure is produced by back pressure from the hydraulic system, the weak feel can only mean there is a space for the T/O bearing to move into - and that can only mean the pressure plate has moved forward of its own accord. I really don't see how the pedal could feel like it's 1/2 way pushed in unless the pressure plate has some how started to depress on its own. The only other time I have felt anything like this on a car was during my days fooling around with Datsuns. In a couple of instances, I shifted so hard (and the motor has so much HP) that I snapped the ring that makes up the pressure plate (it's like a tension ring with flexible teeth around it).. when that ring broke, the pedal felt like it was half gone - since the pressure plate could no longer flex completely back to return the pedal. But in that case, once it broke, that was it - i.e. the pedal was half dead and stayed like that - never came back. In the case of the 360, why the pedal would feel like that only during high RPM's is something I can't quite picture. What is changing under high RPM's that doesn't manifest itself at all RPM's? The only thing I can even remotely imagine is that the pressure plate is coming apart at higher RPM's, but then settling back together at RPM's below 7K or 8K. I suppose if the main ring of the pressure plate had a crack in it, but the overall tension in the ring kept it intact, then things would operate as normal most of the time. Then (assuming this scenario), at higher RPM's, the rotational force might tend to spread the ring apart (extending the crack) and this could mimic what I ran into with my Datsun - i.e. the loss of tension in the fingers of the pressure plate due to a cracked pressure plate ring. The only other explanation is this: if the disc is worn down, it might allow the pressure plate to over extend in its resting position. In other words, the fingers of the pressure plate relax back too far (i.e. over extend upon release). Then during high RPM's, the centrifugal force would tend to spin the fingers in (back to a centered axis) of their own accord. That actually would produce the feeling I'm feeling. I bet that is what is going on. Let me draw a graphic and post it along with this post so you can see what I mean. I bet that is what is taking place. If you look at the first pic, this is the clutch normally. With no major disc wear, the fingers of the pressure plate rest in a verticle plane. However, in the 2nd picture, you can see what would happen with heavy clutch wear. In this case, the pressure plate would rest further forward, which would result in the fingers over extending (outward towards the T/O bearing / back of the car). This places the fingers at a slight angle - contrary to the center plane I have drawn in blue there. Then, during high RPM's, the fingers would tend to want to "spin back into" that center plane, since the centrifugal would be great enough to over come the spring tension in the pressure plate (I'm assuming). When/if this occurs, then the result would be the pressure plate fingers pulling back into that verticle plane, which would pull them away from the T/O bearing (which in turn would mimic someone pushing the clutch pedal in). I think this is the most likely explanation for what is taking place. That's my story and I'm sticking to it... In any event, I guess if I keep the 360 long enough, I will eventually have to tackle this job and replace the clutch. Either that or call John or Brian and peak over their shoulders with my camera while I touch the bumper. As much as I like Brian and John, it violates every fiber of my manhood not to replace the clutch myself on the Ferrari hehe. Ray Image Unavailable, Please Login Image Unavailable, Please Login
I do not know who you talked to at FNA but the only one there that has hands on experience does not even work in that department. There were one or two passing that BS around that the flywheel is concave and should not be resurfaced. Bullschit. The factory does not agree. The shop manual even gives a spec for the maximum amount to be removed. Brand new flywheels off the shelf are flat. The flywheel was made very small and thin and warp to a concave shape with use from all the heat. During a clutch job they are resurfaced and the parts are replaced and once again all works well. The problem you are experiencing has been common on several Ferrari's over the years when they elect to use French or British clutches which are for the most part trash. Over the clutches life the fingers of the diaphram change angle as a result of disc wear. When they get to an extreme angle centrifugal force tries with varying degrees of success to hold the pressureplate in a disengauged position after you have pressed the pedal down. That can result in either a very light feel of the pedal under the foot or in extreme cases no, or delayed reengaugement after the pedal is released. My old friend Mac Tilton always claimed that in the case of AP that it was done intentionally to reduce clutch life. But them Mac has an ax to grind against them. He won a $26,000,000 industrial espionage suit against them. The complete buffoons in the technical department at FNA giving technical advice to the kids fixing the cars is a huge problem. Few of the mechanics have the experience required to know that they are being told a bunch of bullschit. It is a direct result of FNA's hiring policies. None of them has ever been hands on with Ferrari and they are just shooting from the hip.
Yes, I was wondering about that as well - because as you point out, in the manual it shows a picture of the flywheel and it appears flat. It also lists a min thickness, as well as a "maximum flatness deviation on the working surface" of 0.05 mm (~ .002"). So that tends to indicate that the surface of the flywheel is flat and needs to stay flat. Although in the manual, they do show some exploded view (see below) that shows a degree angle of some sort (?). But I don't understand what they are showing in the cut-away or what part of the flywheel that is, since I haven't seen one in person. So I don't know if that little angle area they are indicating is a part of the flywheel where the clutch touches or what. Anyway, on your run down of what is taking place, that's a spot on description of what I am experiencing - right to the lack of disengagement in several cases. At first I couldn't figure out how it could be happening, but now it makes perfect sense. At least knowing the "why of it" makes me feel a little better. As far as doing the clutch myself, I'm on the fence about. I just moved to a new place, so the garage is a disaster area. I haven't even moved all my tools over here yet, so doing the clutch would be a nightmare in the making. Nevertheless, tonight I'm going to read through the manual and see what is involved with separating the gear box from the motor - even if you or John do it, I still want to read up on it. I do recall when I saw John do the clutch on a 2000 360, he just sort of pivoted the gear box over to one side as I remember. I'm not sure if he disconnected all the oil lines or not - but I think he said he did. BTW, for the record, he's just as worried about me doing this job as anyone else hehe. Anyway, for now at least knowing what is taking place in there makes me feel a bit better. I'll just baby the clutch like we spoke about on the phone for the time being. Brian, thanks again for the info... we'd be lost on here without ya! Ray Image Unavailable, Please Login
wait... actually... now I see the bevel. If you look closely at the manual, they are indicating that there is a slight bevel on the surface of the flywheel there. Let me photoshop the other side of the flywheel in there so it's more clear. Okay, see image attached below. Look at the exploded view - it very definitely is indicating that the flywheel surface has a very slight angle to it where it receives the clutch disc. It also shows angle specs there from what I can see in the exploded view. So if someone where to toss the flywheel on a traditional surfacing machine, it would grind off that bevel that Ferrari puts in. Whether this would change much, I don't know - but when I spoke with FNA, they explained to me that the bevel was F1 technology that allows the clutch disc to flex into that bevel in the flywheel (kind of like flexing into a cone), thereby resulting in additional clamping force. Maybe it's only a very slight angle (as shown in the cut-away), but it must be there for a reason. It does seem like having two flat surfaces to pinch the clutch disc would be better than having the flywheel side beveled, but I'm not going to second guess how Ferrari builds their cars As far as I know, I'm reading the manual correctly as far as what they are trying to show. Ray NOTE: Following is a full cut-away of the flywheel. The top (in the drawing) would be the engine side - the bottom is where the clutch disc rides. Image Unavailable, Please Login
I believe what you are seeing is a tolerance. It is just a little over .002 inches. Grab a new one off the shelf. They are flat. After running the life of a clutch they are typically .014-.016 inches concave as a difference between the height of the outer diameter of the working surface to the inner diameter of the working surface. If I extrapolated that to their measuring area we would have more like .030-.040 inches. In any event what we are doing is working and has been working since 99 and Ferrari is still having trouble making them work.
I'm tempted to order one just to see it But for now, I'm going to focus on my landscaping and just baby the clutch. The whole thought of replacing the clutch makes my head hurt I wonder, did they make any updates to the pressure plate since the introduction of the car? I'm wondering if maybe the tension was changes to help combat this problem of the PP spinning open at higher RPM's. Or perhaps they just figure when it gets to that point it needs a new clutch anyway. Anyway, it looks like a new clutch will be on the todo list soon enough. Right now, it's all about planting trees and zeroing in my pellet gun for a little "pest control" as it were > Ray
You may have a point there. Just off the cuff, it does seem like a bevel in the face of the flywheel would tend to sacrifice clamping pressure across all but the highest RPM's (when the disc flexed into that cone shape). I would think just two flat clamping surfaces (i.e. the flywheel and the pressure plate) would produce the best holding force. But again, since I haven't even held a flywheel or clutch/PP assembly in my hands, I don't know. Either way, it appears (if I'm reading the manual correctly) that the angle of attack there is very small. I'm not sure what they are showing, but it appears to be 0.04 degrees in that one exploded view. I would have to get out the calculator to figure out the height difference between the inner lip and outer edge of the flywheel surface. Can't be much though, like you say. Anyway, did I mention I ordered a .22 cal pellet gun??? Ray
With regard to the question of the flywheel having a bevel or not, please refer to this thread for more current information: http://www.ferrarichat.com/forum/showthread.php?t=151532 From what I can see, (now that I have a flywheel here) the flywheel is flat on the surface where the clutch disc mates. As Brian mentions above, I think what the manual is pointing out is something to do with tolerances in the face of the flywheel or something. The one I have here appears to be perfectly flat on the mating surface. Ray
Ray: I have exactly the same problem on my 01 spider. Soft clutch at high rpms, normal at other times. Did you solve the problem? Thanks.
I also had happen what you guys are describing with the 6 speed 360. I had a new clutch installed and the problem went away.
Yes, the thrust bearing was changed at that time. I also had the transmission mount replaced too. My car had about 18k miles when the work was done in June 2009. I bought it with 6k miles on the clock in 2006. I'm not sure if replacing the clutch at 18K miles is normal or not for a Fcar as I don't know how the previous owner drove for the first 6k miles. I know a Ferrari clutch is a different animal, but it'll be interesting to see how many miles I can get out of this clutch as my previous manual cars easily went 100k-150k miles between clutches.
As per post above I had a similar problem. See link below to my thread in Technical area...... http://www.ferrarichat.com/forum/showthread.php?t=283145&highlight=clutch+high+rpm In my instance, having replaced the clutch master cylinder (which did have evidence of a small leak) the problem was ultimately diagnosed as a kink in the oil line from the reservoir to the master cylinder which wasn't allowing fluid to reach the clutch master cylinder probably. A re-routing of the supply pipe resulted in a solution for me.
I looked further into the kinked line theory. Attached is a photo of my clutch line at the front of the engine bay just as it exits the central tunnel. Instead of a smooth radius there is a fairly sharp bend and narrowing of the tube. I wonder if this could be responsible for the problem. If anyone has the rear underfloor off their car and could check this pipe for me I would appreciate it. Are they all bent like this? Thanks. Image Unavailable, Please Login
To the OP - only just seen this thread now and gather you put new clutch plus bearing in. It was deff the thrust bearing that failed. Unfortunately you need the clutch out to get to it and so might as well replace clutch as well. My bearing failed too and despite the clutch being fine i was getting the same 'floppy' pedal. Upgrading the thrust bearing to an uprated Hill engineering is the way to go to avoid future failure. Its a common problem and well known.
Just found this thread. I am having the exact same problems, feels like very short throw for clutch and had a hard time getting into 5th. This was only at high speed. What was the final solution? I have read clutch,re-routing of pipe, bleed the master cylinder, etc. I just bought my car from FoW two weeks ago, I need to know what the issue is so that i can have a clue as to what I am talking about when I go see them Monday. Thanks.
Hard time getting into fifth at high speed only sounds classic symptom of the shifter bushing needing replacement. Do a search on that and see?
I own the original car in this thread. I know the clutch was replaced and a Hill Engineering throwout bearing installed about 2 years ago. There is no unusual behavior with high rpm shifting.
