To get to the clutch you have to remove the airbox and the transmission. I show how to to do that here.

• 13 BMW 1983 R80ST Remove Air Box & Pulse Air System
• 23 BMW 1983 R80ST Remove Transmission

I previously installed the flywheel and you can see how I do that here.

• 21 BMW 1983 R80ST Remove Clutch

Next up is installing the clutch. The 1983 R80ST uses the same clutch as the 1983 R100RS, that I documented. So, I will link to parts of that document in this one, as appropriate.

• 21 BMW 1983 R100RS Install Clutch

Tools

EME provides a special tool for centering the clutch plate. Centering the clutch plate is important because the transmission input shaft has to align with the clutch plate. EME has two tools; one for pre-1981 clutches, and the other for 1981+ clutches, which is the one I use for the 1983 R80ST clutch.

Parts

All the clutch parts were provided by Euro MotoElectrics (EME) for free to support me in completing this charity rebuild project. When I’m done I will auction the R80ST and donate all the proceeds to the Motorcycle Relief Project that helps military and first responders with PTSD using a week long motorcycle ride with daily counseling.

EME now has a clutch kit, EME Part# ClutchKit512, that provides all the parts you need to replace the clutch. These are the parts in the kit.

Qty EME Part Number     BMW Part Number   Description                                   1    ClutchPlate512EDL     21 21 1 451 512        CLUTCH PLATE 1    PressurePlate200        21 21 2 302 200        PRESSURE PLATE 1    ClutchHousing280       21 21 1 457 280        HOUSING COVER 1    ClutchSpring508          21 21 1 338 508        DIAPHRAGM SPRING 6    ClutchWasher377        21 21 1 242 377        TOOTH LOCK WASHER 6    ClutchBolt680              21 21 1 338 680        FILLISTER-HEAD SCREW – M7X18

The parts are the same as the original parts BMW supplies manufactured by Fichtel & Sachs. Here are some pictures of the clutch parts for the 1983 R80ST

Video

I shot a short video summarizing this work.

VIDEO: 1983 BMW R80ST Install Clutch

Preparing Clutch Parts

I show how I do that in the 1983 R100RS document.

• 1983 R100RS: Preparing Clutch Parts

Below are some pictures for the 1983 R80ST.

Install Clutch Parts

I show how I do that in the 1983 R100RS document.

• 1983 R100RS: Install Clutch Parts

How The Clutch Disk Centering Tool Works

The centering tool has a long pin that fits into the hole in the center of the guide ring that’s mounted on the rear nose of the crankshaft. This is the hole the clutch rod fits into. When I mount the clutch pack, I hold it in place on the face of the flywheel with the centering tool ensuring that the splines in the sleeve of the clutch plate are centered so the transmission input shaft will mount inside the sleeve of the clutch plate.

Balance Marks Orientation

I orient the flywheel so it’s balance mark is at the bottom.

On the 1983 R80ST, the balance mark on the flywheel, clutch housing cover and clutch pressure plate were not in positions that allow me to offset all three marks by 120 degrees. The flywheel balance mark was half-way between two of the clutch mounting bosses. I tried several orientations of the clutch housing cover and pressure plate on the flywheel and found one the placed the balance marks on the clutch housing cover and pressure plate with the best separation from the flywheel balance mark.

I use a paint pen and mark the tab between the mounting holes in the clutch housing cover that will be at the top of the flywheel with a “T” for top. Then I mark the corresponding strap on the clutch pressure plate with a “T” to help me assemble them correctly on the flywheel. I also add a “T” on the inside of the clutch housing cover to make it easier to align the clutch pressure plate on the correct pin of the clutch housing cover.

I install the clutch plate so the sleeve will point toward me from the back of the motor. This is critical as the sleeve is what the input shaft splines on the transmission connect to. Here is the clutch pack ready to install on the face of the flywheel.

I install the clutch pack with the “T” on the clutch housing cover at the top using the clutch plate centering tool to hold the pack in place. Then I insert three of the new clutch screws and serrated washers, one in each set of holes.

I check that the pins on the clutch housing cover go into the holes on the flywheel before I tighten the screws so I don’t damage the pins or the flywheel.

I use an Allen socket to snug bolts in a cross-wise pattern to compress the diaphragm spring. Then I torque them to 15 Ft-Lbs. That’s a low value, so I use my INCH-Pound wrench set to 130 INCH-Lbs.

The clutch is now installed.

It looks much better than what I found when I removed the original clutch.