6MT operating question!
04-13-2012, 11:25 PM
#1
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e36 318i, 2004 sti
6MT operating question!
Ok so lately I have been having a problem with my 6MT. Does anyone have any diagrams regarding it? My question is does this transmission have a slave cylinder? I was able to use all data for a minute and couldnt find a slave cylinder. Only a master cylinder located next to the pedal.
Thanks in advance!
Thanks in advance!
04-14-2012, 10:26 AM
#2
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Recently somebody posted that he was going to change his clutch and posted links to some kits. The kits included a circumferential slave cylinder.
I haven't seen parts lists, schematics, or physical evidence, but I'd bet that's the case. That also means that you'll probably have to drop the tranny to service the slave cylinder.
What sort of issues are you having?
I haven't seen parts lists, schematics, or physical evidence, but I'd bet that's the case. That also means that you'll probably have to drop the tranny to service the slave cylinder.
What sort of issues are you having?
04-14-2012, 10:32 AM
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e36 318i, 2004 sti
Yes I did see that thread. The clutch kit wasnt made for these cars specifically right? My issue, Ever since I got the car the Clutch seemed to engage (different). Now once and awhile when I WOT and shift the clutch pedal doesnt return fast. It will slowly engage gear and than take a second to fully return. I do NOT ride the pedal when I drive. I have a feeling the previous owner did however.. 
. I only have 30k.. Im worried to drive her now and be stranded like my subaru did to me all the time...
. I only have 30k.. Im worried to drive her now and be stranded like my subaru did to me all the time...
04-14-2012, 10:47 AM
#4
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The kit may have been for a C230 which would have peaked my interest but I suspect that they are all similar. I think outside slave cylinders are obsolete now.
Does your clutch drag? It could be the spring in your clutch, but I doubt it. It seems to me more likely that it's one of your cylinders. It could be either one. Unfortunately, I don't know how I would easily test it. If you disconnected the hose from the master to the slave and then pressurized the line, it might tell you if if the master is the problem.
Does your clutch drag? It could be the spring in your clutch, but I doubt it. It seems to me more likely that it's one of your cylinders. It could be either one. Unfortunately, I don't know how I would easily test it. If you disconnected the hose from the master to the slave and then pressurized the line, it might tell you if if the master is the problem.
04-14-2012, 12:55 PM
#6
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If you have a new master cylinder, that makes it a little easier. You change that and bleed it and see if that solves the problem.
I was thinking about my test a little more and there are some things I'm not sure of that may make it an ineffective test. For example, how much pressure should you put on the fluid to the master to see if it retracts? If you do do the test, the situation may become obvious, but if not, you may not learn much. It's a situation I don't think I've seen before.
One thing I forgot to ask is are you losing fluid? If you are and you don't see it near the master, it's probably the slave. Is there a way to see if fluid is collecting from the slave? That might be another check. As I think about it more, I suspect that one or the other or both cylinders is leaking. It's highly unlikely that the spring from the clutch is failing.
One thing to remember is that all things being equal, the clutch hydraulics will not last as long as the brake hydraulics since it's being used a lot more.
I was thinking about my test a little more and there are some things I'm not sure of that may make it an ineffective test. For example, how much pressure should you put on the fluid to the master to see if it retracts? If you do do the test, the situation may become obvious, but if not, you may not learn much. It's a situation I don't think I've seen before.
One thing I forgot to ask is are you losing fluid? If you are and you don't see it near the master, it's probably the slave. Is there a way to see if fluid is collecting from the slave? That might be another check. As I think about it more, I suspect that one or the other or both cylinders is leaking. It's highly unlikely that the spring from the clutch is failing.
One thing to remember is that all things being equal, the clutch hydraulics will not last as long as the brake hydraulics since it's being used a lot more.
04-14-2012, 02:02 PM
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It's my fault for confusing Tim. I've had him convinced that there was not a slave cylinder, not in the traditional sense at least. I told him that his throwout bearing was operated by a hydraulic line that runs "inside the tranny". My bad for not knowing it's actually called a circumferential slave cylinder.
I think the take home point here either way is that it looks like the master cylinder is the only one that can be ordered separately? where this "CSC" may only be available in a kit with the clutch?
So, he's almost gotta attempt the master cylinder first before needing to drop the tranny
I think the take home point here either way is that it looks like the master cylinder is the only one that can be ordered separately? where this "CSC" may only be available in a kit with the clutch?
So, he's almost gotta attempt the master cylinder first before needing to drop the tranny
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04-14-2012, 02:52 PM
#8
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Yeah, those new fangled technology things can throw people off! 
I first saw those circumferential slaves was for race cars. I didn't realize that they are used in street cars. I'm not sure the reason. It is simpler because there is no linkage, etc., but then if you need to change it it's a bigger deal.
I would assume it can be ordered separately, but it might make sense to replace the whole thing while the tranny is out since it's such a pain to take it out again.
I really think think trying a new master is the way to go. At the worst, you end up with a new m/c and since this stuff wears faster than the brake master, he's that much ahead of the game. If the slave is bad... well, it was bad already and he's only out the cost of the m/c but I think it is a good investment on a couple of different levels.
I first saw those circumferential slaves was for race cars. I didn't realize that they are used in street cars. I'm not sure the reason. It is simpler because there is no linkage, etc., but then if you need to change it it's a bigger deal.
I would assume it can be ordered separately, but it might make sense to replace the whole thing while the tranny is out since it's such a pain to take it out again.
I really think think trying a new master is the way to go. At the worst, you end up with a new m/c and since this stuff wears faster than the brake master, he's that much ahead of the game. If the slave is bad... well, it was bad already and he's only out the cost of the m/c but I think it is a good investment on a couple of different levels.
04-15-2012, 05:19 PM
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e36 318i, 2004 sti
I was on the freeway and just pulled it back up. There is no fluid leak that i have found. I just pulled the pedal back up with my hand while on the freeway. It feels like a clutch pedal on a miata... . My first attempt is to fix the master cylinder.
. My first attempt is to fix the master cylinder.
04-15-2012, 06:57 PM
#15
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weird im at 80+k miles and have never had any issues with mine, bought it with 40k on it 4 years ago...only glitch that it has is it doesnt like going into first sometimes on the first shift, i have pump it back and forth 2-3x before it decides to slide into gear...weird
04-15-2012, 07:00 PM
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e36 318i, 2004 sti
Yeah im assuming that the previous owner (a girl and i have many reasons to believe so!) operated the car with her left foot resting on the clutch pedal..
04-15-2012, 09:03 PM
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Yep. Disk as in clutch disk. If she rode the clutch pedal, the disk is going to rub against the pressure plate and the flywheel - like dragging the brakes. Ugh! is right!
04-15-2012, 09:18 PM
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e36 318i, 2004 sti
My mechanic friend tested the clutch (idk if this method works) in idle he put it into 6th and it still moved forward indicating the clutch was still strong? Has anyone heard of this method?
04-15-2012, 10:50 PM
#21
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That doesn't seem like much of a test to me. The test you want is how well does it hold under high torque. What does it do when you are accelerating from a stop? going uphill? Does the clutch slip or chatter? Of course in your case, the problem is with the actuating mechanism.
If it ends up that you have to change the slave cylinder, I would advise you to change all of it while you are at it. You'll know what you have and you know you won't have to go in your bell housing for a long time.
If it ends up that you have to change the slave cylinder, I would advise you to change all of it while you are at it. You'll know what you have and you know you won't have to go in your bell housing for a long time.
04-15-2012, 11:44 PM
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Does your clutch slip if you nail it in 5th or 6th gear?
Finatics problem seems more hydraulic in nature and i think he's on the right track with the cylinder/hydraulics.
04-15-2012, 11:55 PM
#23
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That's actually a pretty good test and is used a as fairly accurate measure of how much friction/bite your clutch disc has.. Theory/thinking being that if the clutch can move the car (which from a stop, in 5th or 6th gear takes a lot of friction without slipping) then the clutch disc itself is in decent shape.
Does your clutch slip if you nail it in 5th or 6th gear?
Finatics problem seems more hydraulic in nature and i think he's on the right track with the cylinder/hydraulics.
Does your clutch slip if you nail it in 5th or 6th gear?
Finatics problem seems more hydraulic in nature and i think he's on the right track with the cylinder/hydraulics.
I agree that his problems are likely hydraulic in nature. My concern was that if the PO rode the clutch pedal a lot, the life of his clutch could be a lot less than expected. If the hydraulic problem was the slave cylinder, it might be advisable to replace it all since it is probably a bear to get the tranny out and replace the slave. However, I don't know how bad it really is since I've never done it... It just looks like a bear!
Thinking further, I'd like to modify my previous comments. A lot depends on if the clutch is over designed or under designed for the motor. I have known of some cars where the clutch was somewhat fragile. I haven't heard of any lately (so maybe that is more a thing of the past) and it's probably more likely that MB over designed the clutch rather than under designing it. If the slave needs to be replaced, the other clutch components should be inspected and may not necessarily need to be replace. I might replace the throw out bearing regardless, but then I'm a little paranoid about them. It probably comes from my days with an old '70 VW Beetle!
Last edited by ncmudbug; 04-16-2012 at 12:08 AM. Reason: Thinking further...
04-16-2012, 04:24 PM
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e36 318i, 2004 sti
That doesn't seem like much of a test to me. The test you want is how well does it hold under high torque. What does it do when you are accelerating from a stop? going uphill? Does the clutch slip or chatter? Of course in your case, the problem is with the actuating mechanism.
If it ends up that you have to change the slave cylinder, I would advise you to change all of it while you are at it. You'll know what you have and you know you won't have to go in your bell housing for a long time.
If it ends up that you have to change the slave cylinder, I would advise you to change all of it while you are at it. You'll know what you have and you know you won't have to go in your bell housing for a long time.
That's actually a pretty good test and is used a as fairly accurate measure of how much friction/bite your clutch disc has.. Theory/thinking being that if the clutch can move the car (which from a stop, in 5th or 6th gear takes a lot of friction without slipping) then the clutch disc itself is in decent shape.
Does your clutch slip if you nail it in 5th or 6th gear?
Finatics problem seems more hydraulic in nature and i think he's on the right track with the cylinder/hydraulics.
Does your clutch slip if you nail it in 5th or 6th gear?
Finatics problem seems more hydraulic in nature and i think he's on the right track with the cylinder/hydraulics.
I'd never heard that test so this might be another time for me to learn something! Thanks, glocati!
I agree that his problems are likely hydraulic in nature. My concern was that if the PO rode the clutch pedal a lot, the life of his clutch could be a lot less than expected. If the hydraulic problem was the slave cylinder, it might be advisable to replace it all since it is probably a bear to get the tranny out and replace the slave. However, I don't know how bad it really is since I've never done it... It just looks like a bear!
Thinking further, I'd like to modify my previous comments. A lot depends on if the clutch is over designed or under designed for the motor. I have known of some cars where the clutch was somewhat fragile. I haven't heard of any lately (so maybe that is more a thing of the past) and it's probably more likely that MB over designed the clutch rather than under designing it. If the slave needs to be replaced, the other clutch components should be inspected and may not necessarily need to be replace. I might replace the throw out bearing regardless, but then I'm a little paranoid about them. It probably comes from my days with an old '70 VW Beetle!
I agree that his problems are likely hydraulic in nature. My concern was that if the PO rode the clutch pedal a lot, the life of his clutch could be a lot less than expected. If the hydraulic problem was the slave cylinder, it might be advisable to replace it all since it is probably a bear to get the tranny out and replace the slave. However, I don't know how bad it really is since I've never done it... It just looks like a bear!
Thinking further, I'd like to modify my previous comments. A lot depends on if the clutch is over designed or under designed for the motor. I have known of some cars where the clutch was somewhat fragile. I haven't heard of any lately (so maybe that is more a thing of the past) and it's probably more likely that MB over designed the clutch rather than under designing it. If the slave needs to be replaced, the other clutch components should be inspected and may not necessarily need to be replace. I might replace the throw out bearing regardless, but then I'm a little paranoid about them. It probably comes from my days with an old '70 VW Beetle!
