the presure plate with a stage II SPEC, the clutch feels great but it will not disengage fully...foot all the way down and it's very hard almost impossible to put in gear. mechanic says it's the pressure plate ANY IDEAS?
The first thing to check is that there is no air in the clutch master/slave cylinder circuit. This can happen if the slave cylinder hose is disconnected (not necessary to pull the trans). A simple bleeding will usually work. Sometimes the slave cyl. needs to be removed, turned so the bleed port is "up", and a clamp put on the pushrod and compressed. If this doesn't fix the problem, try to drive the car a few hundred miles of stop-and-go driving to get the "fuzz" off the disk (i.e., break in the clutch). The third possibility involves the self-adjusting feature. It is my understanding that Spec uses the factory BMW pressure plate as a starting point, including the problematic plastic self-adjusting ratchet. This may not be adjusted properly (i.e., too far "advanced"), as if the disk were thinner than it is. This can't be reset without pulling the pressure plate and using the BMW tools (the design of the self-adjusting mechanism is such that it can only self-adjust as wear occurs - the disk gets thinner).
If all the above doesn't work, either there is an incipient failure of the master or slave cylinder, or the pressure plate was built with too much leverage (too little clamp plate displacement for the available pedal throw). This seems unlikely as Spec has been doing this for a while, but is sometimes a problem with modified pressure plates.
Wow! you are #2 out of 2 people who installed a SPEC clutch and complained of drivability after the install. Maybe it's not ain install issue. The first guy who installed a SPEC clutch on his M5 ended up trading in for a X5. This is not good.
Wow! you are #2 out of 2 people who installed a SPEC clutch and complained of drivability after the install. Maybe it's not ain install issue. The first guy who installed a SPEC clutch on his M5 ended up trading in for a X5. This is not good.
At some point, a trend develops......
Do NOT drive the car with this dragging clutch symptom. The transmission is having difficulty because it's tiny synchros are incapable of stopping the "dragging" clutch disc. They will very quickly overheat and warp. If you repeat this tranny shifting exercise many times, you can add a $5K tranny to your shopping list. The synchros are not sold separately and nobody can rebuild your tranny except Getrag under an exchange core basis.
Last edited by Lscman; 11th December 2004 at 21:09.
I think my several posts on the dangers of SAC ("disabled" or not) should be made a "sticky" as a service to all E39 owners.
Sounds like you are definitely having a SAC issue. Due to the design of that mechanism, even SPEC's technique of "locking" the mechanism is not always effective.
Why did you get the Stage2? The kevlar disk (I won't say "I told you so" until the moderators make this info a "sticky" here on M5board) is completely inappropriate for applications that see significant drag... such as a heavy M5 with lots of torque in daily-driving situations. The link that I have posted a few times as a guideline for choosing clutch materials:
I would never use a kevlar disk in anything other than a lightweight road-racing car. It has no benefit for a street car, and will be very easy to permanently cook. With the incomplete release situation you are experiencing, you may have already glazed the disk.
This is the info about SAC that I have posted before (moderators - sticky?):
Many E39 owners have experienced mushy clutch feel, inconsistent engagement, and premature wear of the clutch in their manual-transmission cars.* The reason is quite simple - the original BMW (LUK-manufactured) clutch in the E39 has a new "SAC" (Self Adjusting Clutch) design.* This new mechanism built into the clutch pressure plate is supposed to keep the clutch pedal engagement point the same as the clutch wears... but in all reality, it's a case of* "an answer to a question that nobody was asking." They have added a layer of complexity and feedback isolation, filling a need that didn't need filling - it is not too often that anybody notices that their clutch engagement point as moved 1/2" over 50K miles.
The SAC mechanism itself causes problems; it over- or under-adjusts the pressure plate and therefore causes the clutch to slip or burn out prematurely. They are also known to shift, causing the pressure plate release fingers to slip off the plate, keeping 1/3 of the pressure plate engaged at all times. Bottom line is that the only fix is a complete clutch job, and your dealer is likely to claim "driver abuse". We have seen it happen too many times.
The SAC mechanism may not give a clean release like a standard clutch. Instead of just two sets of springs, there is an adjuster mechanism that makes engagement feel mushy or slow. Hard use, even within normal usage parameters, can cause the self-adjuster to slip.
the guy's @ SPEC are sending me out another clutch kit, lets see if this one works out...if the original kit turns out to be defective should i pursue reimbursment for my mechanics labor?
the guy's @ SPEC are sending me out another clutch kit, lets see if this one works out...if the original kit turns out to be defective should i pursue reimbursment for my mechanics labor?
Why not insist on a full parts refund and cut your losses? Isn't this a fool me once scenerio? Shame on somebody...
This could be an 0 for 3 exercise for this particular M5 Spec Clutch assy. A "disabled SAC" design sounds super lame to me. Is that something you want? Are you willing to absorb labor fees & inconvenience for two failed experiments?? Are you aware that another fellow had the same misfortune? It sounds to me like their "defeated SAC" setup is overadjusted or underadjusted when shipped & they don't quite know what they're doing. The contraption that BMW uses to adjust a SAC from initial settings is real complex. They used to do this when mixing new and used parts, but they later learned to use all new.
Last edited by Lscman; 15th December 2004 at 07:18.
How many miles did you put on this clutch? Any track days? Did you not look a the UUC option? Just curious as one day many of us will cross this same path.
Good luck. I agree with the comment above, time is money so getting the best working solution next time might make you feel better about it.
DMC
Last edited by dmccrary90025; 16th December 2004 at 06:16.
original clutch lasted 62K, the SPEC unit had o miles, never made it out of the workshop, i am going to try them one more time. i don't track or drive excessively hard so i thought this unit would be ok...this time i'm going to install it myself..i'll let keep y a'll posted
just had clutch replaced and...
Linear Mode
