I removed the drive shaft before taking having it powder coated. You can see how I do that here:

• 33 BMW 1983 R100RS Remove Drive Shaft

Now that the swing arm is back from the powder coater, it’s time to install the drive shaft into the swing arm.

Parts

I decided to replace the torsion shock spring. The snap ring is a use once item, so I replace that also.

Part #	Description	Qty
26 11 1 237 189	SNAP RING-Drive Shaft	1
26 11 1 237 184	COIL SPRING	1

Tools

I use the Cycle Works tool for compressing the drive shaft spring so I can install the snap ring retaining collar and the snap ring. It’s the same tool I use to remove the drive shaft.

I use snap ring pliers to help install the snap ring. These allow me to reverse the action of the pliers when I squeeze them: squeeze to close the jaws or squeeze to open them.

Video

Here is a video that summarizes the procedure shown in this document.

VIDEO: 1983 BMW R100RS Install Drive Shaft

Drive Shaft Parts

Starting in the 1979 model year (09/1978), the drive shaft design changed. It uses a spring to absorb sudden torsion shock loads caused by engine acceleration and deceleration. This provides a smoother ride and less stress on the universal joint and the drive shaft. The drive shaft parts are shown in the picture below.

• A-Drive Shaft
• B-Spring Retaining Collar
• C-Spring
• D-Yoke
• E-Bell Coupling
• F-Snap Ring Retaining Collar
• G-Snap Ring

The new drive shaft spring measures 45 mm long.

Assemble Drive Shaft in Swing Arm Tube

Before I install the drive shaft into the swing arm tube, I clean out the swing arm tube to remove any debris left by the powder coater. I flush the inside of the swing arm tube with hot water an then push paper towels through it a couple times with a long shank cleaning brush I have.

After I insert the drive shaft into the swing tube, I install the spring retaining collar followed by the spring, the yoke and then the bell housing. Here are pictures of the orientation of the parts on the drive shaft so you can see the order the are installed.

NOTE:
You can’t install the drive shaft with any of these parts installed, you have to install them after you insert the drive shaft into the swing arm tube. The pictures show you how they go onto the drive shaft after you insert it into the swing arm drive shaft tube.

Assemble Cycle Works Spring Compressor Tool

I show how to assemble the tool here:

• Assemble Cycle Works Tool

I tightened the collar nuts six full turns to be sure I had plenty of clearance above the snap ring retaining collar to install the snap ring.

Install Snap Ring Retaining Collar and Snap Ring

I use snap ring pliers to expand the snap ring. There is little room to work inside the mouth of the swing arm tube so I place the snap ring toward the end of the fingers of the pliers so it will be easy to slide the ring off the pliers. I expand the ring just enough to get it over the lip of the drive shaft. Then I use a flat blade screw driver to push the snap ring off the fingers of the snap ring pliers over the drive shaft and then down into the groove in the shaft. It took me two attempts to get the snap ring in place.

NOTE:
I have heard from several people about how hard it is to install the snap ring. I decided to try this technique and I think it made installation of the snap ring easy.

I verify that the snap ring is seated in the groove visually and also by using a flat blade screw driver to rotate it in the groove.

I remove the pressure on the drive shaft spring by alternately loosening each coupling nut one turn at a time while I watch the snap ring retaining collar to be sure it captures the snap ring uniformly to lock it onto the drive shaft.

The drive shaft is installed inside the swing arm tube.

Revisions

2022-05-31  Minor edit for clarity to snap ring plier description.