6 speed super heavy clutch problem

[Nic_S]

Hi guys

Even since I bought my SA Build E34 540i 6 speed, I was worried about the super heavy clutch. Eventually the pipe that goes to the salve cylinder exploded. So I figured I'll bite the bullet and replace the clutch as the old was slightly slipping anyway.

Clutch Kit Part No.: 21211223633

So I have a brand new clutch in there, but I have the exact same problems. The clutch pedal is ridiculously heavy, but the master cylinder and slave cylinder seems fine. It has a new slave cylinder for that matter. And because there were only 72 of these build here in SA, it's difficult for anyone to really know how it should be. It's not like I can just try out someone else's as I don't even know if there is another 6 speed anywhere near me.

I'm no expert at the inner workings, so I've spend the entire morning looking up on how the system works and came across an article on how to replace the clutch on a 3 series. Link: Pelican Technical Article: BMW Clutch Replacement (http://www.pelicanparts.com/bmw/techarticles/E36-Clutch_Replace/E36-Clutch_Replace.htm)


I know it's not exactly the same as my car, but can anything in the pick below cause my super heavy clutch problem? It doesn't seem like it to me, but like I said, I don't know much about all of it.
http://www.pelicanparts.com/bmw/techarticles/E36-Clutch_Replace/pica7.jpg


I'm scared the new pipe (Which I had have made up) will also explode. So any advice would be greatly appreciated.

Regards

[Bill R.]

Its never going to be as light as a toyota or honda clutch pedal but when new the pedal effort is pretty good compared to a 55 chevy or any early american muscle car.
High pedal effort can be caused by a number of things, if you have a new clutch, I would check the pivot point on that throwout bearing arm as in the picture.
Also you don't use any grease on the sliding surface of a bmw e34 throwout bearing unlike the picture you have posted. Grease such as shown can cause problems.
The new throwout bearing has a plastic/nylon/teflon? surface that you don't use grease with. I would buy the newest part number throwout bearing arm that bmw has, they have redesigned it a couple of times and the newest is supposed to be optimized.

The guide sleeve which is what bmw calls that collar that the throwout bearing slides on has to be in good condition, smooth with no burrs or gouges and no wear. And no grease. The input shaft splines have to be clean and smooth with a light coating of molykote to allow the clutch disc to slide smoothly. If somebody in the past has put the wrong slave cylinder on with a different bore diameter clutch effort will be greatly increased also. you can check here for the instructions not to grease the throwout bearing guide tube. (http://tis.spaghetticoder.org/s/view.pl?1/00/04/59)

[genphreak]

I have an M50 and an M60 powered e34. The M60/6 is heavier, but it would only cause trouble for a real weakling. I don't find it unpleasant, cetainly not in comparison to my old 11" Ford single plate.... lol

Question is- what do you mean by heavy? I imagine that it would make you concerend about hitting traffic and acutally hurt your knee after a while. Not objective measures i know, but hey...

Do you think that too much pressure caused the pipe failure?

I'll tkae a wild guess as to the cause:

The throw out bearing not greased properly -or perhaps with the wrong grease? Wrong grease will melt at the wrong point and leave the surfaces dry.

unless the car has a modified, non factory drive train (original auto?).

Pressure to disengage/re-engage is probably not the problem, it may just be that the pressure is at the wrong point- eg just off disengage or too far away from the disengage point. If non-stock items were used, the locations may not be right and effort required be a symptom. Is the clutch an e39 clutch- or an e34 one?

[Nic_S]

It's an original E34 540i 6 speed. No mods.

I'm willing to put my head on a block and say that it's heavier than anything you've ever driven. I'm sure the old pipe exploded because of the pressure. It's really THAT heavy.

A friend of mine told me that his dad had a similar issue with his old 950 Moto Guzzi. He took the clutch apart and put everything back together properly. He said that there was something wrong with the springs. Could I have a similar cause??

[genphreak]

Follow Bill's advice to the t. He has had more experience than most on these. When you find the new part, post the part number and price so we can all know :)

Also, there is a rubber insulator bung that could need replacement when doing this...

[Nic_S]

So I had a closer look at the slave cylinder which I had replaced because the old one would somehow dump all the fluid during the night. The mechanic that worked on the car replaced it with the exact same size cylinder as the old one.

But yesterday I go under the car to take a closer look and on the slave cylinder there are 2 number. The one is 6634 and is printed at the bottom of cylinder while the other is 20 and is printed on the bit where you connect the pipe to it. So it seems there is a 20mm diameter cylinder in there which is wrong as it should be 26.99mm. This means that one of the previous owners had the wrong one installed and for some reason it was left like that. WTF??!!

So now I need to buy another new cylinder and they are actually pretty expensive with $140 being the cheapest I found in the states, but locally it will most likely be MUCH more. Our government loves targeting the motorist with high taxes as we are forced to drive our own vehicles with our public transport being the joke that it is.

Anyway, I'll let you guys know if the cylinder, when I'm able to get one, fixes the problem.

[Bill R.]

So I had a closer look at the slave cylinder which I had replaced because the old one would somehow dump all the fluid during the night. The mechanic that worked on the car replaced it with the exact same size cylinder as the old one.

But yesterday I go under the car to take a closer look and on the slave cylinder there are 2 number. The one is 6634 and is printed at the bottom of cylinder while the other is 20 and is printed on the bit where you connect the pipe to it. So it seems there is a 20mm diameter cylinder in there which is wrong as it should be 26.99mm. This means that one of the previous owners had the wrong one installed and for some reason it was left like that. WTF??!!

So now I need to buy another new cylinder and they are actually pretty expensive with $140 being the cheapest I found in the states, but locally it will most likely be MUCH more. Our government loves targeting the motorist with high taxes as we are forced to drive our own vehicles with our public transport being the joke that it is.

Anyway, I'll let you guys know if the cylinder, when I'm able to get one, fixes the problem.

Your 540 has a 26.99mm which you already determined, the m5 had a 20.64mm and the 530 v8 had a 22.20 mm slave, E30's had a 20.64 also. They all seemed to have the same size master 19.05mm .

BMA has it for 94 USD. Here (http://www.bmaparts.com/ShopByVehicle.epc?q=1995-BMW-540i--/v8_4.0l_m60-Clutch--Components&yearid=1995%40%401995&makeid=BMW%40%40BMW%40%40X&engineid=1012442%40%40540I+%2FV8_4.0L_M60%40%40540 I&catid=Clutch+Components&subcatid=Clutch Slave Cylinder&mode=PA)