33 BMW 1983 R100RS Remove Rear Wheel, Rear Drive, Shocks & Swing Arm

It is easier to remove the four drive shaft coupling bolts that connect the drive shaft to the transmission output flange with the rear wheel on the bike. That way I can use the wheel to immobilize the drive shaft when I remove the bolts.

NOTE:
You will see red duct tape on parts of the bike in some of the photos. I use this “red flag” when I remove oil or gear lube, I need to torque a fastener, or I haven’t finished work on something and I have to stop. It helps me prevent inadvertent disasters. All I have to do is remember to reapply these red flags after I clean, repaint and powder coat the parts. Maybe I’ll try the Uncle Billy “string-on-the-finger” trick (see, “It’s a Wonderful Life”)  

Remove Drive Shaft Coupling Bolts

I remove the special bolt on the right rear of the transmission that secures the speedometer cable and the battery (-) ground cable. The bolt has a longitudinal hole that lets the the swing arm to breath as the rear end moves up and down. I also run a wire through the hole to ensure it is not blocked.

Speedometer Cable Mounting Bolt Hardware Detail

Speedometer Cable Mounting Bolt Hardware Detail

Speedometer Cable Bolt Has A Breather Hole

Speedometer Cable Bolt Has A Breather Hole

Speedometer Cable Bolt Has A Breather Hole

Speedometer Cable Bolt Has A Breather Hole

Then I pull use a small screw drive to pry the rubber boot off the ridge on the transmission, slide it up the speedometer cable and pull the speedometer cable with it’s bushing out of the speedometer drive gear hole in the transmission.

Speedometer Cable Detail & Bushing Detail

Speedometer Cable Detail & Bushing Detail

Speedometer Cable & Bushing Detail

Speedometer Cable & Bushing Detail

To prevent anything from falling into the transmission speedometer drive gear hole, I fill the bushing with a piece of blue shop towel and insert the bushing back into the hole.

Protecting Transmission Speedometer Gear Hole From Crud Getting In

Protecting Transmission Speedometer Gear Hole From Crud Getting In

Protecting Transmission Speedometer Gear Hole From Crud Getting In

Protecting Transmission Speedometer Gear Hole From Crud Getting In

I remove the two steel bands that secure the rubber bellows that fits between the swing arm and transmission.

Remove Transmission-to-Swing Arm Bellows Straps

Remove Transmission-to-Swing Arm Bellows Straps

They aren’t in good shape and come apart when I remove them. The rear strap fits under a small metal tab welded to the front of the drive shaft housing on the swing arm.

Transmission Bellows Straps-In Bad Shape

Transmission Bellows Straps-In Bad Shape

Transmission Bellows Fits Under Retainer Clip On Rear of Swing Arm

Transmission Bellows Fits Under Retainer Clip On Rear of Swing Arm

I slide the front end of the bellows off the transmission and bend it back to get access to the four drive shaft coupling bolts.

Transmission Bellows Pulled Off Transmission

Transmission Bellows Pulled Off Transmission

Drive Shaft Transmission Coupling Bolt

Drive Shaft Transmission Coupling Bolt

If rear brake is still installed, I put the transmission in second gear, sit on the seat, put my foot on the rear brake pedal and then loosen the bolts. But in this case, the rear brake has been removed and the bike is on the portable motorcycle lift. So, I use a different technique to immobilize the rear drive when I remove the drive shaft coupling bolts; a large, long screw driver through the web of the cast wheel with the transmission in second gear.

Blocking Rear Wheel From Rotating

Blocking Rear Wheel From Rotating

Blocking Rear Wheel From Rotating

Blocking Rear Wheel From Rotating

Now I use a 12 side box end 10 mm wrench and remove the four drive shaft transmission flange bolts. It takes a goodly grunt to break them free.

NOTE:
A common practice is to put blue loctite on the threads of these bolts. So, if your’s seem very hard to turn, you can try using a small flame on your propane torch directly on the head of the bolts to melt the loctite. Be careful as you can burn the rubber bellows if you aren’t careful.

10 mm 12 Sided Box Wrench

10 mm 12 Sided Box Wrench

Remove Drive Shaft Transmission Coupling Bolt

Remove Drive Shaft Transmission Coupling Bolt

Drive Shaft Transmission Coupling Bolt Detail

Drive Shaft Transmission Coupling Bolt Detail

NOTE:
Be careful as you unscrew the bolts to not drop them as they will be hard to retrieve from inside the swing arm.

After I remove a bolt, I remove the screwdriver, rotate the wheel to position another to the outside of the coupling where I can get the box wrench on it and then reinsert the screw driver. I continue until I remove all four bolts.

Drive Shaft Transmission Coupling Bolts-New Style

Drive Shaft Transmission Coupling Bolts-New Style

NOTE:
There are two styles of these bolts. The old style, part#  26 11 1 230 414, is longer, 15 mm, and had a split washer, part# 07 11 9 930 840. The washers tend to break so BMW revised these to use a shorter bolt, 13 mm, without the washer, part#  26 11 1 242 297. If your bike has the old style bolts, replace them with the new style.

Remove Rear Wheel

Now that I have removed the four drive shaft flange bolts, I remove the rear wheel. I remove the rear axle nut on the left side and then the pinch bolt on the right side. The axle nut should have a large flat washer, but someone replaced it with a split locking washer and the pinch bolt hardware is incorrect too, so I’ll replace all of it with the correct hardware.

Rear Axle Nut & Washer

Rear Axle Nut & Washer

Remove Rear Axle Nut

Remove Rear Axle Nut

Rear Axle Hardware Detail-Not The Correct Washer

Rear Axle Hardware Detail-Incorrect Washer

Rear Axle Pinch Bolt

Rear Axle Pinch Bolt

Remove Rear Axle Pinch Bolt

Remove Rear Axle Pinch Bolt

Rear Axle Pinch Bolt Hardware Detail-Incorrect Bolt

Rear Axle Pinch Bolt Hardware Detail-Incorrect Bolt

Rear Axle Pinch Bolt Hardware Detail-Incorrect Hardware

Rear Axle Pinch Bolt Hardware Detail-Incorrect Hardware

There is a hole in the left side of the axle so I can insert the rod in the bike tool kit or a screw driver to remove the axle. But, it won’t slide easily since the brake plate is binding on the axle. I remove the brake torque arm lower mounting bolt from the plate and the axle slides out easily under the muffler.

NOTE:
There is a serrated washer behind this bolt that is not stock. And the arm is mounted on the front side of the brake plate; it should be on the back side..

Rear Torque Arm Lower Mount

Brake Torque Arm Lower Mount-On The Wrong Side of  the Plate

Remove Torque Arm Lower Mount

Remove Brake Torque Arm Lower Mount

Brake Torque Arm Lower Mount Hardware Detail

Brake Torque Arm Lower Mount Hardware Detail-Wrong Washer

Brake Torque Arm Lower Mount Hardware Detail

Brake Torque Arm Lower Mount Hardware Detail

Pulling Rear Axle Out

Pulling Rear Axle Out

Remove Rear Axle

Remove Rear Axle

The torque arm plate is oriented as shown below and has a casting number stamped in the side with the reinforcing ribs which faces to the outside of the wheel.

Brake Torque Arm Plate Orientation

Brake Torque Arm Plate Orientation

Brake Torque Arm Plate Casting Number

Brake Torque Arm Plate Casting Number

Brake Torque Arm Plate and Axle Hardware Detail

Brake Torque Arm Plate and Axle Hardware Detail

The rear tire does not want to go past the splines in the rear drive, so deflate it and it comes out. It is the correct size, 4.00 x 18, but I guess it has a fat profile.

Rear Tire Can't Pass Rear Drive Splines

Rear Tire Can’t Pass Rear Drive Splines

Remove Tire Valve Core To Deflate

Remove Tire Valve Core To Deflate

Rear Tire Slides Past Rear Drive Splines

Rear Tire Slides Past Rear Drive Splines

I check the splines on the inside of the rear wheel for excessive wear and they appear to be in very good condition.

Rear Wheel Showing Splines

Rear Wheel Showing Splines

The rear disk mounts to the cast wheel with five bolts. There is also a circular strip of metal with bent tabs to secure the bolts and prevent them from backing out.

Rear Wheel Disk Rotor Detail

Rear Wheel Disk Rotor Detail

Rear Wheel Disk Rotor Bolt Detail

Rear Wheel Disk Rotor Bolt Detail

Remove Brake Torque Arm

Now, I remove the brake torque arm from the bracket on the bottom of the swing arm.

Remove Sub-frame End of Brake Torque Arm

Remove Front End of Brake Torque Arm

Sub-frame End of Brake Torque Arm Hardware Detail

Front End of Brake Torque Arm Hardware Detail

Front End of Brake Torque Arm Hardware Detail

Front End of Brake Torque Arm Hardware Detail

The front end of the torque arm has a bend and a bushing on the side of the torque arm that faces inward while the rear end of the torque arm is straight and also has a bushing that faces inward.

Front End of Brake Torque Arm Has A Bend

Front End of Brake Torque Arm Has A Bend

Rear End of Brake Torque Arm is Straight

Rear End of Brake Torque Arm is Straight

Here is how the bike looks now.

Rear Wheel Removed & Brake Torque Arm Removed

Rear Wheel Removed & Brake Torque Arm Removed

Remove Rear Drive & Shocks

The rear drive has a stud the bottom of the right shock mounts to. I remove that shock first, but leave the left shock mounted to the swing arm until I remove the rear drive. This keeps the swing arm from dropping down against the frame with the weight of the heavy rear drive.

The inside of the rear drive has splines that engage splines in the rear wheel to connect the rear wheel to the engine.

Inside of Rear Drive with Splines

Inside of Rear Drive with Splines

I check them for wear and find the profile is rectangular and not rounded, chipped or cracked, so they are in very good condition.

Rear Drive Splines Detail-Good Condition

Rear Drive Splines Detail-Good Condition

I remove the shock from the swing arm starting at the top. That allows me to rotate the shock out of the top enclosure to remove it from the stud at the bottom of the shock.

Left Top Shock Bolt

Left Top Shock Bolt

Remove Left Shock Top Bolt

Remove Left Shock Top Bolt

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

Left Shock Bottom Mounts to Stud in Rear Drive

Bottom of Left Shock Mounts to Stud in Rear Drive

Remove Left Shock Lower Nut From Rear Drive

Remove Left Shock Lower Nut From Rear Drive

Left Shock Lower Hardware Detail

Left Shock Lower Hardware Detail

Rotate Top of Left Shock To Free It From Housing

Rotate Top of Left Shock To Free It From Housing

Remove Left Shock From Rear Drive Stud

Remove Left Shock From Rear Drive Stud

These are not the original shocks (thank goodness). There is a metal bushing inside the rubber bushing of the shock.

Right Lower Shock Hardware Detail

Right Lower Shock Hardware Detail

Now I remove the four 12-sided bolts that secure the rear drive to the swing arm. Due to interference with the swing arm, I use a universal joint adapter on the socket.

Rear Drive 12 Sided Nuts

Rear Drive 12 Sided Nuts

Remove Rear Drive 12 Sided Nut

Remove Rear Drive 12 Sided Nut

Rear Drive Hardware Detail

Rear Drive Hardware Detail

I use a plastic hammer to free the rear drive from the swing arm. As soon as I get it loose, I understand why I had to use the hammer; the gasket that is supposed to be used isn’t there and instead someone used sealant. Not the correct approach.

Separating Rear Drive From Swing Arm

Separating Rear Drive From Swing Arm

Drive Shaft Rear Coupling Detail

Drive Shaft Rear Coupling Detail

Rear Drive Detail-Note Sealant That SHOULD NOT be Used

Rear Drive Detail-Note Sealant That SHOULD NOT be Used

Rear Drive Removed

Rear Drive Removed

How The Bike Looks After Rear Wheel and Drive Are Removed

How The Bike Looks After Rear Wheel Is Removed

Now I remove the left shock. The lower shock bolt won’t clear the left exhaust pipe, so I have to remove the left muffler to get the bolt out.

NOTE:
If you install the left lower shock mount bolt with the bolt head on the inside of the swing arm, you can pull it out and not have to remove the muffler when you want to remove the shock or the swing arm.

Remove Left Top Shock Bolt

Remove Left Top Shock Bolt

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

Left Shock Top Hardware Detail

The bottom shock bolt and nut are different. The bolt is shorter, has finer threads, and the nut is thinner. This helps when removing the wheel by providing more clearance.

Left Lower Shock Has A Slim Nut

Left Lower Shock Has A Slim Nut

Left Lower Shock Has A Slim Nut

Left Lower Shock Has A Slim Nut

Remove Left Lower Shock Bolt

Remove Left Lower Shock Bolt

Left Muffler Removed To Remove Left Lower Shock Mount Bolt

Left Muffler Removed To Remove Left Lower Shock Mount Bolt

Remove Left Rear Shock Lower Bolt

Remove Left Rear Shock Lower Bolt

Left Shock Lower Mount Hardware Detail

Left Shock Lower Mount Hardware Detail

Left Shock Hardware: TOP-Top Mount Hardware, BOTTOM-Bottom Mount Hardware

Left Shock Hardware: TOP-Top Mount Hardware, BOTTOM-Bottom Mount Hardware

Remove The Swing Arm

The swing arm is secured with two pivot bolts with lock nuts to the frame. These are behind a black plastic cover. I remove these.

Remove Swing Arm Pivot Plastic Cover (Note Slot)

Remove Swing Arm Pivot Plastic Cover (Note Slot)

Swing Arm Pivot Cover Detail

Swing Arm Pivot Cover Detail

The lock nut requires a cut down 27 mm socket with a thinner body so it will fit inside the frame. The nut should be quite tight so I use a breaker bar to remove it.

Cut Down 27 mm Socket For Swing Arm Lock Nut

Cut Down 27 mm Socket For Swing Arm Lock Nut

Remove Swing Arm Lock Nut

Remove Swing Arm Lock Nut

Swing Arm Lock Nut Hardware Detail

Swing Arm Lock Nut Hardware Detail

I use an Allan key to remove the two pivot pin. I hold onto the swing arm as I remove the last pivot pin so it doesn’t fall onto the floor.

Remove Swing Arm Pivot Bolt

Remove Swing Arm Pivot Bolt

Rear Swing Arm Pivot Bolt

Rear Swing Arm Pivot Bolt

Rear Swing Arm Removed

Rear Swing Arm Removed

This what the bike looks like now.

Bike After Rear End Removed

Bike After Rear End Removed