I’m going to have the swing arm powder coated. So I remove the drive shaft to avoid any possibility of damage to it and the swing arm bearings. I will replace the swing arm bearings as they are likely 40 years old and there is rust in many places on the bike so it’s possible the swing arm bearings have not been cared for.
I use the Cycle Works drive shaft coupling puller tool for removing the drive shaft from the swing arm. I’ve purchased a number of tools from them and each has been easy to use and a clever design. I also use their swing arm bearing tool to pull and install these bearings.
Remove Swing Arm Assembly
The procedure to remove the swing arm for the R100RS is the same as for the R75/6 project. You can read about how I remove the swing arm here (click the title to open the page).
This procedure covers removing the sub-frame, but you don’t have to do that to remove the swing arm. Since the sub-frame was removed, I immobilize the drive shaft by sitting on the rear tire. If the sub-frame is installed, you can press on the rear brake lever to keep the drive shaft from turning when you loosen the drive shaft-to-transmission mounting bolts.
Remove Swing Arm Bearings
The procedure is the same for the R100RS as for the R75/5. You can read about how to do this with the Cycle Works tool here.
Remove Drive Shaft Coupling Nut
The drive shaft has a large coupling on the end that fits into the final drive. Removing this coupling allows the shaft to pulled out of the swing arm shaft. The coupling is secured by a larger nut and fits tightly on a taper ground on the end of the drive shaft.
I put the drive shaft in my vice so it clamps on the u-joint that is part of the drive shaft.
There is a second u-joint that is flexible and attaches to the transmission. YOU DO NOT WANT TO CLAMP THAT JOINT.
My vice has a rotating joint so I can rotate the jaws from vertical to horizontal. This makes it easy to get to the nut. Otherwise I would have to get a stool to stand on to reach it if is vertical in the vice.
I use my 1/2″ breaker bar with a 25 mm socket. The comes loose pretty easily which is not such a good thing. So I’m glad I’m taking the swing out as I can ensure the nut is torqued properly when I reassemble it.
Assemble Cycle Works Bell Housing Removal Tool
Here are the parts to the Cycle Works tool.
The aluminum cylinder goes inside the bell housing.
The two-piece aluminum collar fits under the neck of the bell. The lip goes under the bottom of the bell.
The two long bolts go through the short side of the collar pieces. One washer goes under the bolt head and the other under the nut.
The top plate goes on top of the aluminum cylinder in the center of the bell housing. I put axle grease on the short bolts as they will be tightened to remove the bell housing from the shaft.
The washer goes under the head of the short bolt and the bolt threads into the top of the two aluminum collar pieces.
I snug the four top plate bolts down and then tighten the four collar bolts tight.
This is how the bell coupling puller looks when it’s assembled on the bell coupling.
Remove Drive Shaft Bell Housing
I put the swing arm in my vice so the top plate is convenient to get to. I set my torque wrench to 15 FT-Lbs and evenly tighten the four top bolts. The top plate can handle up to 25 FT-Lbs before deforming and you can go higher than that if need be. My bell housing pops loose easily.
Here are the drive shaft components after removing them from the swing arm housing.
Note the colored paint inspection marks on the drive shaft u-joint and the bell housing. The bearings in the u-joint are permanently sealed and do not require lubrication.