SACH clutch just fitted still slips??

[mr_bmw]

ive just fitted a a sach clutch its the same clutch bmw use but have there name on it along with sach picked it up for Ԛ£100 bmw want 160 for the same clutch with there name on it i ive had a mate fit it and it still slips even worse than before he told me to drive it 200 miles to let the clutch inbed then if its the same take it back to him when im pushing the pedal down the rpms are going up but i dont feel as much torq as the engine is putting out any advice to what it is?????

[Adammcf]

Could just be that it needs adjusted so its not riding the clutch so much when you lift off the pedal. Im not sure how it works on the BMW but there's usualy some form of adjustment on the clutch arm.

[E30Adam]

The clutch can't be adjusted on the BMW and it shouldn't need bedding in.

Maybe your input shaft seal of the gearbox is leaking causing gearbox oil to make the clutchplate slip.

[mr_bmw]

where is the input seal? is it inside the gear box? i did have the gear box oil changed the oil that was in it was a black goldish no chunks of metal thank god and to thick the new oil was red pink looking oil,when changed we emtpy it from the bottom and filled it up from the bottom the seal must be inside where the shaft is coming from the gear part of the box?? it wasnt leaking when it was put on i gues things can chang when puting box back together i do remember the top of the box where u usauly fill it was leaking when turned up side down he told me it has to breath and wasnt to be sealed

[E30Adam]

The input shaft seal is inside the bell housing. I'd be a bit concerned about pink gearbox oil. The pink stuff is ATF which is for use in auto boxes only. The correct colour should be a goldy colour for manual gearbox oil. When he changed the clutch he would have been able to see inside the bell housing if there were any leaks of oil.

I'd check with him that he's used the corrrect oil. If he's used ATF then the chances are that it's leaking because it's a lot thinner than manual gearbox oil. I'm a bit confused as to how you managed to fill it up from the bottom, did you remove the gearbox completely to do it? You should drain from the bottom and fill from the side.

[cabrio327i]

Some of the manual boxes did use ATF oil, bit of a grey area though with BMW, they say theres some sort of paint code on the bell housing,which ive never seen, and depends on if the box has female or male drain plugs, i think it mentions the oils in the Bentley manual could be wrong though , get in touch with the dealer and give them vin no- they should know. cheers Dave

[mr_bmw]

yes the gear box came out complety i dont think it is atf he said he uses this oil for mec and bms i will check with him i asked him 3 times if it is the wright oil and said yes this man works in a garrage where they do only clutches and boxes hes done a few bms including the m3 e46

[Guest]

You need to do 50 miles without putting your foot down to let the oil residue for storage protection to burn off, driving hard in the first 50 miles will cause hot spots on the face and nacker the unit.

[E30Adam]

You need to do 50 miles without putting your foot down to let the oil residue for storage protection to burn off

Rubbish

[Guest]

Boge Sachs use a film of oil to stop rusting and damp wrecking the surface area, by driving the car hard it mases a massive temperature increase on the surface causing hot spots.

[mr_bmw]

adam what grade gear box oil is suitable for my 1991 325 sport is it 5 75 /90? youv got me thinking it might be leaking from the input shaft seal, i never had this prob be4 with it but are you + aboout the red pinkish is autobox oil i rang him and said he forgot the grade of oil but told me to bring it to his work on monday he would find out and look at it ,he took a good look at it before he put it back 2gether and said the flywheel had been skimed in the past he doesnt think this problem is the fly wheel he said it is still good if the shaft seal is leaking would it leak from the gear box housing aswell onto the floor

[ed325i]

Yes you can put ATF oil in. uesd to do it all the time when I worked for BMW, can't remember why this was done it was 15 years ago. It is not something I would put in mine now.

[ed325i]

Hi, Did he just fit the clutch plate or a kit? it could be a weak diaphragm spring or a warped pressure plate.

[mr_bmw]

in the box was a kit not just the plat thers another piece that it came with that the plat sits in (sach m20 clutch kit)

[Guest]

A few manufacturers switch to ATF fluid in gearboxes simply to aid shifting qualities, ATF is thinner and makes shifting easier especially when cold.

[cabrio327i]

Hi, You said the flywheel has been skimmed,if its not been done properly meaning when its been skimmed they have not removed the dowells that locate the pressure plate before machining, and only refaced the actuall clutch disc area up to the dowells then this is the problem, you will have too much clearance between the centre plate lining and the flywheel face, causing the clutch to slip because there will not be enough spring pressure, cheers Dave

[johnl320]

what tourer11 said about the oily residue on the pressure plate to stop it rusting is right but if this guy has been fitting clutches and gearboxes for so long then surely he would have cleaned the oil off. If he didn't then i wouldn't touch him with a barge pole. the oil will contaminate the friction plate and the action of " burning it off " will shorten the life off the clutch.

[E30Adam]

what tourer11 said about the oily residue on the pressure plate to stop it rusting is right but if this guy has been fitting clutches and gearboxes for so long then surely he would have cleaned the oil off. If he didn't then i wouldn't touch him with a barge pole. the oil will contaminate the friction plate and the action of " burning it off " will shorten the life off the clutch.

Yes he is right about there being an oily residue, if it wasn't there then the clutch would be rusty by the time it reached you. What I was disagreeing with was the fact that he says you should drive it for 50 miles without depressing the clutch.

The oil should be thoroughly cleaned off with a spirit during fitting and of course should not be burnt off. I still don't think this is the problem though but I might be wrong.

[Demlotcrew]

Hi, You said the flywheel has been skimmed,if its not been done properly meaning when its been skimmed they have not removed the dowells that locate the pressure plate before machining, and only refaced the actuall clutch disc area up to the dowells then this is the problem, you will have too much clearance between the centre plate lining and the flywheel face, causing the clutch to slip because there will not be enough spring pressure, cheers Dave

Id go with this, sounds like its the problem.

Andrew

[Demlotcrew]

what tourer11 said about the oily residue on the pressure plate to stop it rusting is right but if this guy has been fitting clutches and gearboxes for so long then surely he would have cleaned the oil off. If he didn't then i wouldn't touch him with a barge pole. the oil will contaminate the friction plate and the action of " burning it off " will shorten the life off the clutch.

Yes he is right about there being an oily residue, if it wasn't there then the clutch would be rusty by the time it reached you. What I was disagreeing with was the fact that he says you should drive it for 50 miles without depressing the clutch.

The oil should be thoroughly cleaned off with a spirit during fitting and of course should not be burnt off. I still don't think this is the problem though but I might be wrong.

I left a clutch out in the rain in its box for months and it wasnt rusty.

[Quaser]

When he said "dont put your foot down" i think he meant dont accelerate hard!

[johnl320]

i wasn't disagreeing with you Adam and when you said it was rubbish i agree entirely nobody in their right mind would fit it without cleaning it then there would be no need to burn it off . Hang on a minute, don't i normally argue with you ? i must be getting old , or going soft , or losing my mind . I,m just off out to burn the oil off my new brake discs!! see you in 50 miles

[Guest]

When he said "dont put your foot down" i think he meant dont accelerate hard!

That is exactly what I meant, and any "decent" clutch fitting or motorsport centre will tell you the same, a clutch plate is like a break pad, you bed it in slightly before you abuse it.

[mr_bmw]

i didnt see him clean the clutch plat but i picked it up and it had no sticky oily residue it looked and felt clean when i got it the box was already open they deliverd it to his work and was fitted at his uncles garrage shouldnt u be able to tell from felling it?? he also said i cant skim the flywheel cause theres not enough fly wheel to skim would have to buy a new one he said the flywheel he looked at it before he put all back 2gether and said flywheel wouldnt afect the performance

[Demlotcrew]

People skim fly wheels only if the the friction plate rivets eat into the surface, not to get more performance. (they take metal from the back for this)

Andrew

[mickdeakin]

hi presuming you have not got oil contamination................read on

hows the clutch pedal does it feel hard
have you got any free play in the pedal
or is it solid
should be about 1 inch to 1 1/2 inch of free play if not not the hydraulics could be loading the diaphragm causing premature slip

was the kit a three piece
are all the components from the same manufacturer if not
if it has been mixed it could have a drive plate with thinner material on thus reducing clamp load.
original drive plates are double finned (twin marcel springs)
with a material thickness of 3.8mm per side plus .150 of marcel spring
giving an overall thicknes of around 11.0 mm to 11.40mm in its free state
if the flywheel has been machined you must reduce the outside of the flywheel by the same amount as you have removed from the working surface ....if not it would have the same effect as fitting a thinner drive plate
hope this helps
regards mick

[Toby_Unna]

The input shaft seal is inside the bell housing. I'd be a bit concerned about pink gearbox oil. The pink stuff is ATF which is for use in auto boxes only.

adam ATF is specified for some bmw manual gearboxes. maybe not on an m20 box, i've never owned one and have no idea.

but the e28 sports box (as in e30 m3) and e34 m30 manual boxes all specify ATF - which is indeed pink - and have warning labels on the box to this effect (eg. the yellow label on the box in my sig)

unless the slave cylinder is jamming or there is another hydraulic problem (or incorrect assembly although i can't see how this would cause slipping) then oil contamination is possible.

i'd remove the slave cylinder on the gearbox bellhousing, therefore leaving the clutch permanently engaged, then drive it a little without clutch - this will show whether the problem is hydraulics/pedal adjustment or a more serious issue with the clutch plate itself.

[mr_bmw]

THE SLAVE SYLINDER was on its way out it was leaking so i got a new one fitted the same time the clutch was fitted the hydrolic was bleeded out and was dirty after a few pumps on the clutch it was clear and there was no air in the system, when i said its still slipping i mean when i put my foot down more than half way to the floor from low revs it feels ok when the rpm is over 3000 the power proper kicks in and u can feel the torq but from 3500 to 5500 and over the rpm needle starts to move up faster it feels like the car has to play catch up with the rpm needle=power put out by the engine ,do u think it might have something to do with it being superchiped,fuel presser boost valve k&n induction kit,full exaust twin dtm system do u think its the lsd sliping or i

[Toby_Unna]

the slave cylinder rod pushes outwards when you put the clutch down. so i was thinking if the rod was jamming then it would be like not fully taking your foot off the clutch pedal.

maybe the wrong slave cylinder is fitted and the rod on it is too long? i'd be surprised though, as most bmws i've had apart used the same part...

[mr_bmw]

thanks for all your replys i took it to bexlymotorworks 2day and let them take for a test drive they said its not sliping at all and i was worrying for nothing they said its fine nothing to worry about i might be a bit