© 2013 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.

Clutch Work w/o BMW Special Tools

According to BMW and other shop manuals, you need a couple of special tools to perform maintenance on K bike clutches. In reality, you don't.

Saving The Clutch Boot

At the rear of the clutch pushrod there is a rather expensive rubber boot - part 23131338731.

There is a spring inside of this boot and if you fully release the clutch arm with an old boot then the spring inside of the boot can tear it.

You can often avoid this if, when the clutch cable is detached from the clutch arm, you use zip-ties (or string/wire) to keep the clutch arm from fully releasing.

 

Getting The Clutch Apart

Once the six bolts around the perimeter of the clutch assembly have been removed, it is often difficult to remove the rear piece to get the clutch apart. You can carefully pry the clutch apart around the outer edge using a 5 1/2" long mini pry bar/nail puller. Examples are the Vaughan 222 or Titan 11505.

 

Be sure to get a 5 1/2" mini pry bar. The heads on 7" pry bars are usually too large to fit in between the bellhousing and clutch assembly.

BMW Holder - Part 112800

The purpose of this special tool is to hold the clutch housing in place so the you can remove/install the clutch nut without having it turn the engine.

By inserting a block of wood into the upper left corner between the bellhousing and one of the clutch housing flanges, you can accomplish the same thing.

BMW Clutch Centering (Alignment) Tool - Part 212670

The purpose of this tool is to center the clutch plate before retightening the six clutch bolts so that the splines of the clutch plate are aligned with transmission input shaft when the transmission is re-installed.

You can buy aftermarket machined aluminum clutch centering tools on eBay for about $25 shipped.

However, I developed my own approach without the need for a special tool of any kind.  Namely, using the transmission itself as your centering tool. 

When you install the clutch plate, tighten the six clutch bolts only enough to hold the clutch plate in place by light friction so that it can still move. Then feel around the edges and use your fingers to get it as well centered as you can.

DO NOT LUBE THE SPLINES YET. Only lube the splines upon final installation of the transmission. Put the transmission in fifth gear (makes turning the input splines via the output shaft easier) and, without the pushrod in, temporarily install the transmission, wiggling it around a little and using the output shaft at the back to turn the input shaft until it mates with the clutch plate.

Then push the transmission all of the way on.  The clutch plate is now centered.  Carefully pull the transmission STRAIGHT back and then, once it is off, tighten the six clutch bolts. (19 Nm)

Before lubing the splines and inserting the clutch pushrod, install the transmission once more to ensure that the clutch plate is properly centered with the six clutch bolts tightened.  Then remove the transmission, insert the clutch pushrod, lube the transmission input splines and execute the final transmission installation. (16 Nm transmission to bellhousing)

© 2013 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.