21 BMW 1983 R80ST Install Clutch

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

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

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.

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.

EME Supplied Clutch Disk Centering Tool-Pre 1981 Clutches

EME Supplied Clutch Disk Centering Tool-Pre 1981 Clutches

EME Supplied Clutch Disk Centering Tool-1981 And Later Clutches

EME Supplied Clutch Disk Centering Tool-1981 And Later Clutches, 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

Clutch Pressure Plate-Flywheel Face

Clutch Pressure Plate Face Toward Flywheel

Clutch Pressure Plate Markings

Clutch Pressure Plate Markings

Clutch Housing-Outside Face

Clutch Housing Cover Outside Face

Clutch Housing Markings

Clutch Housing Cover Markings

Diaphragm Spring-Outside Face

Diaphragm Spring Outside Face

Diaphragm Spring-Face Against Flywheel

Diaphragm Spring Inside Face Against The Flywheel

Diaphragm Spring Markings

Diaphragm Spring Markings

Diaphragm Spring Markings

Diaphragm Spring Markings

Clutch Disk-Outward Face With Sleeve

Clutch Disk Outward Face Has A Sleeve

Clutch Disk Markings

Clutch Disk Outward Face Markings

Clutch Kit Bolts With Serrated Washers

Clutch Kit Bolts With Serrated Washers

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.

Below are some pictures for the 1983 R80ST.

Contamination Removed From Contact Surface Of Clutch Pressure Plate and Clutch Housing

Contamination Removed From Contact Surface Of Clutch Pressure Plate and Clutch Housing Cover

Thin Smear Of Moly 60 On Ridges On Back Of Clutch Pressure Plate

Thin Smear Of Moly 60 On Ridges On Back Of Clutch Pressure Plate

Thin Smear Of Moly 60 On Inside Edge Of Diaphragm Spring

Thin Smear Of Moly 60 On Inside Edge Of Diaphragm Spring

Install Clutch Parts

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

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.

EME Supplied Clutch Disk Centering Tool For 1981+ Clutches

EME Supplied Clutch Disk Centering Tool For 1981+ Clutches

Clutch Disk Centering Tool Inserted Into Sleeve Of Clutch Plate

Clutch Disk Centering Tool Inserted Into Sleeve Of Clutch Plate

Clutch Disk Centering Tool Pin Fits Inside Hole Of Crankshaft Guide Ring

Clutch Disk Centering Tool Pin Fits Inside Hole Of Crankshaft Guide Ring

Clutch Disk Centering Tool Installed To Align Clutch Disk On Crankshaft

Clutch Disk Centering Tool Installed To Align Clutch Disk On Crankshaft

Balance Marks Orientation

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

Flywheel Balance Mark Positioned At Bottom

Flywheel Balance Mark Positioned At 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.

Clutch Housing & Pressure Plate Balance Marks-Flywheel Balance Mark At Bottom

Clutch Housing Cover & Pressure Plate Balance Marks-Flywheel Balance Mark At Bottom

Clutch Pressure Plate Balance Mark

Clutch Pressure Plate Balance Mark

Clutch Cover Balance Mark

Clutch Housing Cover 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.

"T" Paint Mark On Outside Of Clutch Housing Indicates Which Holes Are At Top Of Flywheel

“T” Paint Mark On Outside Of Clutch Housing Cover Indicates Which Holes Are At Top Of Flywheel

"T" Paint Marks On Inside Of Clutch Housing And Strap Of Clutch Pressure Plate To Ensure Clutch Pressure Plate Goes On Correct Pin Of Clutch Housing

“T” Paint Marks On Inside Of Clutch Housing Cover And Strap Of Clutch Pressure Plate To Ensure Clutch Pressure Plate Goes On Correct Pin Of 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.

Clutch Pack Assembled For Installation On Face Of Flywheel

Clutch Pack Assembled For Installation On Face Of 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.

Clutch Plate Centering Tool Installed

Clutch Plate Centering Tool Installed

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.

Clutch Cover Pins Fit In Holes In Flywheel

Clutch Housing Cover Pins Fit In Holes In 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.

Torqueing Clutch Bolts to 15 Ft-Lbs

Torqueing Clutch Bolts to 15 Ft-Lbs

The clutch is now installed.

New EME Supplied Clutch Installed

New EME Supplied Clutch Installed

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

Original R80ST Clutch Is Looking A Bit Bedraggled

Original R80ST Clutch Is Looking A Bit Bedraggled

Original Clutch Condition Was A Bit Bedraggled

Original Clutch Parts After Removal

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