33 BMW 1983 R100RS Install Swing Arm Bearings

I removed the bearings to have the swing arm powder coated, and to replace them since the bike has 83,000+ miles on it and I had no clue if they had ever been replaced. You can see how I removed them here.

Unlike the earlier bearings that require lubrication, the later model bikes like this one use a sealed bearing. Removing them destroys the bearing as you destroy the seal.

Sealed Bearing Gets Destroyed Upon Removal

Sealed Bearing Gets Destroyed Upon Removal

That said, a roller bearing is not a good choice for a swing arm. Roller bearings rely on the roller spinning all the time to distribute grease between the contact surfaces to avoid metal-to-metal contact. In a swing arm, the roller never rotates a full revolution so in time time grease gets pushed out from between the roller and the outer race allowing metal-to-metal contact. Eventually that creates flat spots in the outer race and makes the bearing notchy.

Outer Race Damage-Brinelling

Outer Race Damage-Brinelling

Parts

The new bearing comes with it’s own dust seal included. I replaced the left side swing arm blanking cover as the original one was beat up pretty badly.

Part #                    Description                                                 Qty
33 17 1 241 546  TAPERED ROLLER BEARING – 40X17X17 (from 01/81) 2
33 17 1 239 812  COVER, Swing Arm, Left Side Grease 1

The new bearing is sealed to prevent water from getting into it and is a different size than the earlier swing arm bearing so you can’t use the earlier bearing.

New Sealed Swing Arm Bearing

New Sealed Swing Arm Bearing

Tools

I use a large socket to drive the bearing into the hole in the swing arm. The socket is big enough that it only touches the edge of the outer race and just fits within the hole in the swing arm.  An alternative way to drive the bearing is to put the old outer race on top of the outer race of the new bearing and drive it in.

Large Socket Or Outer Race Can Be Used To Drive New Race Into Hole

Large Socket Or Outer Race Can Be Used To Drive New Race Into Hole

Video

Here is a short video showing the installation of the bearings.

VIDEO: 1983 BMW R100RS Install Swing Arm Bearings

Prepare Bearing & Swing Arm

I remove the black dust seal from the bearing. The outside face of the bearing has a sleeve that extends a bit past the dust seal. The back side of the bearing does not have the dust seal, but does have a bearing grease seal. Be sure you drive the bearing in with the sleeve facing you.

Front Face of Bearing With Dust Seal

Front Face of Bearing With Dust Seal

Removing Dust Cover With My Fingers

Removing Dust Cover With My Fingers

Dust Seal Removed

Dust Seal Removed

Front Face Of New Bearing Has A Sleeve

Front Face Of New Bearing Has A Sleeve

Rear Face of Bearing Has No Sleeve-Note Black Grease Seal

Rear Face of Bearing Has No Sleeve-Note Black Grease Seal

The swing arm bearing holes are different. The right side hole is blanked off by the drive shaft tube while the left side hole opens into a large cavity. To prevent any grease from getting into the left side swing arm cavity, a metal cover plate is installed to seal off the cavity.

Right Side Beating Hole Is Closed Off By Swing Arm Tube

Right Side Beating Hole Is Closed Off By Swing Arm Tube

Swing Arm Left Side Hole Has Large Cavity

Swing Arm Left Side Hole Has Large Cavity

Cover Plate Prevents Grease Going Into Swing Arm Left Side Cavity

Cover Plate Prevents Grease Going Into Swing Arm Left Side Cavity

Cover Plate Installed In Right Side Hole

Cover Plate Installed In Right Side Hole

Install Swing Arm Bearing

i start on the left side bearing so I don’t forget to install the cover plate. I tried using the old outer race to drive the bearing with the large socket on top. I found it hard to keep the bearing from getting cocked in the hole, but I did manage to drive it in.

Using Old Outer Race And Socket To Drive Bearing Cocked The Bearing Easily

Using Old Outer Race And Socket To Drive Bearing Cocked The Bearing Easily

I switched to using only the socket on the right side bearing and it seemed to keep the bearing more centered in the hole as I drove it in.  I hit the socket a couple hard wacks and then look at the alignment of the bearing in the hole. If it’s not even, I hit the edge of the socket over the high side of the bearing to even it out.

Driving The Bearing Into The Swing Arm with Just The Socket Was Easier

Driving The Bearing Into The Swing Arm with Just The Socket Was Easier

I drive the bearing until the top edge of the outer race is  even with the bottom of the chamfer of the bearing hole in the swing arm.

Top Of Bearing Outer Race Even With Bottom Of Chamfer in Swing Arm Hole

Top Of Bearing Outer Race Even With Bottom Of Chamfer in Swing Arm Hole

After I drive both bearings into the holes, I install the black plastic dust seals. Both faces of the seal are the same.

Black Plastic Dust Seat-Both Faces Are The Same

Black Plastic Dust Seat-Both Faces Are The Same

Dust Seal Installed Over Sleeve

Dust Seal Installed Over Sleeve

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