engine and drivetrain Clutch Wont Disengage - 5Spd Swap

[evanb]

Ok got it out today. Everything looked normal. Here are some pictures I took, let me know if you see anything or if you need specific angles or whatever. I may end up pulling the pressure plate and clutch later, too.

[NickVyse]

My problem was in your bottom right hand pic - can't be sure, but I don't think you have the same issue, but it's easy to check. The large round rivet type thing on the spring pushes into the corresponding hole on the pressure plate under compression, except in mine it didn't. The hole was machined too small/the rivet head was too large, thus limiting the travel of the clutch.

 

Hope this makes sense. 

[thehackmechanic]

In medicine, the expression is "when you hear hoofbeats, think horses not zebras." I would prove to yourself that the problem is not the throwout bearing before moving on. That is, I would verify beyond a shadow of a doubt that you have the correct throwout bearing, regardless of what the box said.

 

This thread shows the 323i and 320i throwout bearings next to each other. The important distance is that from the tabs to the front (rotating) face of the bearing. From the photos, I can't tell whether you have one of these or a different throwout bearing.

 

I'm looking through posts to find what the actual distance is supposed to be.

 

--Rob

[thehackmechanic]

On this thread:

http://forums.bimmerforums.com/forum/showthread.php?1214976-Someone-money-shifted-my-car-today&p=16510673#post16510673

 

they list the ears-to-face distance as 25mm for the 320i bearing, and 30mm for the 323i bearing.

[thehackmechanic]

Sorry, forgot to include the first link with the close-up of the two t/o bearings.

 

http://www.bmw2002faq.com/topic/126595-which-throw-out-bearing/

[thehackmechanic]

Here's another post showing two of the 323i 21 51 1 204 525 bearings, one of which is the older all-metal style, the other of which is newer and not all metal. They don't have the same overall length, but DO have the same length from the tabs to the bearing face.

 

http://www.bmw2002faq.com/topic/79796-throwout-bearing-dilema/

 

Attached is a pic of the very bearing I put in my '72tii with the 228mm flywheel and clutch.

 

Forgot to say it looks like your clutch disc is in right-side-up, and the throwout bearing is properly oriented, with the tabs on the clutch lever. Also there's no apparent bending or offset to the clutch fingers.

[evanb]

Looks like from the back of the tabs to the face of the bearing is about 30mm.

So it should work fine.

Is there any way to test the pressure plate and clutch? To make sure the pp is releasing the clutch properly?

[thehackmechanic]

Wow. I'm surprised. But life is full of surprises.

 

Even the measurement notwithstanding, heuristically it looks to me like the "thick" bearing rather than the "thin" one.

 

I don't know of a way to test the clutch.

 

At this point, I would log a call to Ireland.

[Hans]

There should be an FAQ award to whoever solves this one. TOB dimension looks OK. I assume the pivot for the arm is OK? So to review, you're getting full 26mm of pushrod travel but nothing is releasing. Which may mean gap between TOD face and disc release arms is too big. But why? The trans was fully seated against the block? Does the throw out arm go in either way? The plastic tip is on the rod?

Edited January 9, 2014 by Hans

[jgerock]

When installing the pressure plate, did you use new bolts, torqued evenly in a star pattern?

 

Did you use the common centering tool to keep the clutch disc centered in the crankshaft?  (Obviously you used something or else you would have a hard time installing the tranny).

 

When tightening the pressure plate bolts, did you notice the diaphragm "fingers" moving in an even fashion?

 

IF you purchased new pressure plate bolts, did you check their length to see if they weren't too long or had an incorrect shoulder length?

 

Sometimes it is easy to use the wrong bolts in this critical application and sometimes a "new" pressure plate is faulty.

Edited January 9, 2014 by jgerock

[02tom]

Sounds like you've got the brass pivot pin (to replace the plastic BMW 21 51 1 223 328) from Ireland and this should be better than the plastic one, that, if worn or crushed would not allow the clutch to disengage.  

 

One thing that you might try after exhausting all other options, is another slave cylinder.  I've had some relatively new ones go bad after their first removal or older ones go bad when replacing a hydraulic hose and will not work with any amount of bleeding.

[Harv]

Here is a standard one next to the longer typical 228 (or is it 225mm?) TO B.

John

[bmwfan]

I would make sure the disc is not warped and slides smoothly on the input shaft splines. Might be able to check movement of pressure plate with a wood or metal block over pressure plate pivots and a press. Simulating clutch movement to make sure it is not binding.

[skipsfcr]

Dude, not to insult your (or anybody's) intelligence, but put your forefinger on the pilot bearing inner race and make sure it's not seized. They are easily dinged during installation and, if seized, can cause the input shaft to spin all the time, even with the clutch pedal depressed. You might also verify it's installed deep enough while you're at it. At least rule this stuff out.

[thehackmechanic]

I have sent a link to this post to Paul Wegweiser and Ben Thongsai, just to get a couple of fresh sets of eyes on it. Paul concurs that the pilot bearing should be checked, and that the possibility of the clutch pressure plate being bad is not outside the envelope.

 

I've never tried to do this, but... is the hydraulic line from the master to the slave long enough to hook it up with the trani uninstalled, so you can depress the clutch pedal and actually watch the slave move the lever and the lever move the throwout bearing?