33 BMW 1973 R75/5 Remove & Install New Swing Arm Bearings

In page 02 BMW R75/5 General Tear Down, I show to remove the swing arm from the transmission and the rear drive from the swing arm. This is what I started from.

Swing arm disassembled from Frame

Swing arm disassembled from Frame

This page covers removal and replacement of the swing arm bearings and races and the powder coating of the swing arm.

I ordered the swing arm bearing removal tool  and the following parts from Cycle Works in Kansas.

31 41 2 000 331 Swing arm dust seal, Qty (2)
07 11 9 985 005 Swing arm bearing, Qty (2)

Here’s a picture of the tool; “some assembly is required”. This is explained in the included instructions, and I’ll show you how it goes together.

Cycle Works Swing Arm Bearing Puller Kit

Cycle Works Swing Arm Bearing Puller Kit

I found the design of this tool very clever; combining common hardware with a clear understanding of how materials behave under stress.  Very slick.

Assembling The Cycle Works Swing Arm Bearing Puller

First, put the plated nylon lock nut on the plated 16 mm bolt until the threads are just past the top of the lock nut with the bolt and thread faces aligned. In a moment, it’s clear why aligning the faces matters.

16 MM Bolt with Nylon Lock Nut-Faces Aligned

16 MM Bolt with Nylon Lock Nut-Faces Aligned

Next, screw four of the long socket head bolts into the plate with the six threaded holes leaving two adjacent holes open.

Four Screws In Plate

Four Socket Head Screws In the Plate

Screw the bolts into the plate until they are even with the bottom of the plate.

Screws Even with Bottom of the Plate

Screws Even with Bottom of the Plate

Now, place the 16mm bolt with locknut inside the four socket head screws.  Ah … that’s why the bolt and nut faces need to be aligned 🙂

16 MM Bolt Surrounded by Four Socket Head Screws

16 MM Bolt Surrounded by Four Socket Head Screws

Next, put some wheel bearing grease on the top of the 16 mm bolt head. Finally, screw the other two socket head screws into the plate so the 16 mm bolt is surrounded. Then, place the head of the socket screws on the work bench, adjusting them in their holes so all the heads sit flat on the top of the bench.

The long threaded rod has a taper on one end and a hole for an Allen head wrench on the other. Put a little wheel bearing grease on the tapered end. Using an Allen wrench, screw the threaded rod into the center hole of the plate until it touches the bottom of the 16 mm bolt.

Screw Threaded Rod into Center Hole of the Plate

Screw Threaded Rod into Center Hole of the Plate

At this point, the tool is assembled, so its time to use it. As shown here, the dust seal has a metal sleeve in the middle.

Dust Seal with Metal Sleeve

Dust Seal with Metal Sleeve

Use a screw driver to the pop the sleeve out of the dust seal. It comes out very easily.

Removing the Spacer

Removing the Spacer

Insert the Allen wrench into the threaded rod. Then, place the heads of the six socket head screws on top of the rubber part of the dust seal and push down hard enough to deflect the rubber seal and tighten the center threaded rod. This pushes the 16 mm bolt head under the heads of the six Allen head bolts spreading them outward under the edge of the dust seal. Keep tightening the center threaded rod until you see all six Allen bolt heads are lodged under the lip of the dust seal as shown below.

Six Bolt Heads Under the Lip of  the Dust Seal

Six Bolt Heads Under the Lip of the Dust Seal

Puller Positioned to Remove the Dust Seal

Puller Positioned to Remove the Dust Seal

Now, put the metal cylinder over the threaded plate so it is centered on top of the swing arm and not touching the edge of the dust seal. Then put the steel plate and the washer on the center rod and thread the 17 mm nut finger tight down on the washer. Check to be sure the metal cylinder is still centered on the outside of the swing arm and is not touching the edge of the dust seal.

Cylinder, Top Plate and Washer Ready for Nut

Cylinder, Top Plate and Washer Ready for Nut

Use a box end 17 mm wrench to tighten the nut pulling the threaded rod and the dust seal out of the swing arm.  If the puller pops out of the seal, you didn’t tighten the threaded rod tight enough to spread the six Allen head bolts far enough under the lip of the dust seal.  Back off the threaded rod, reinsert the Allen head bolts and tighten the threaded rod  a bit tighter and have another go.

Use 17mm Box Wrench to Pull Dust Seal

Use 17mm Box Wrench to Pull Dust Seal

And here you see the dust seal has been removed an is captured by the heads of the six socket head screws surrounding the 16 mm hex bolt head.

Dust Seal Removed Inside Cylinder

Dust Seal Removed Inside Cylinder

When I tightened the center threaded rod, I over tightened it so the 16 mm bolt head extended too far and got trapped by the socket head screws. When I unscrewed the center rod, the 16 mm bolt wasn’t able to come loose and I couldn’t get the dust seal off the six bolts. So, put the aluminum plate, washer and nut back on and keep tightening the center threaded rod until you hear a “pop” which is the head of the 16 mm bolt going past the socket head screws.

Hex Bolt Pushed Past Screws

16 mm Hex Bolt Head Pushed Past Screws

Now, you can remove the dust seal from the six Allen bolts. You can unscrew two of the socket head screws to free the 16 mm bolt and slide it back inside the Allen head bolts. Then screw the two Allen head bolts back into the plate being sure all six bolt heads are level.

To remove the bearing, just stick you finger in the center and pull it out.  If you are a gentleman of refinement, you can use your pinkie finger to extract the bearing from the race. 🙂

Refined Gentlemen's Method of Bearing Removal

Refined Gentlemen’s Method of Bearing Removal

The bearing race is removed using the same technique: set the heads of the six socket head screws under the edge of the race and tighten the threaded rod until they spread out under the edge under the race.

Ready to Pull the Bearing Race

Ready to Pull the Bearing Race

Again, put the cylinder, metal block, washer and nut onto the threaded rod and use the 17 mm wrench to pull out the race.

On the shock side of the swing arm, there is a metal cap under the race to keep grease from filling up the hollow center section of the swing arm. Mine was stuck to the bottom of the race hardened grease. Fish it out if it doesn’t come out with the race.

The vertical lines you see on the inside of the race in the picture below are due to Brinelling.

Grease Cover and Bearing Race

Grease Cover and Bearing Race

This is caused by the tapered roller bearings pounding against the race and deforming it. The rollers never fully rotate as the swing arm only moves up and down, but doesn’t rotate in a full circle. Eventually, the rollers indent the face of the race.  I expected this due to the age and mileage of these bearings.

Flip the swing arm over and repeat the process on the drive shaft side. There is no grease cover under the bearing race as the tube surrounding the drive shaft blocks any grease from entering the hollow center of the swing arm.

Powder Coating the Swing Arm

I don’t want to remove the drive shaft under the philosophy of “let sleeping dogs lie”, but I am going to have the swing arm powder coated. I want to prevent any direct hits to the universal joint and it’s bearings during bead blasting, Here’s my solution: a custom fabricated Progresso “sock can” over the universal joint.  This took me several hours to fabricate, but it was well worth the time.

Progresso Soup Can "Sock" Over the Universal Joint

Progresso Soup Can “Sock” Over the Universal Joint

If you want a “soup can sock” of your own, send me an Email with your mailing address and I’ll let you know how much it will be with shipping, handling, and if you live in Colorado, sales tax.

I added a warning note about protecting the surface on the other end of the drive shaft tube where the rear drive mounts to the swing arm.

Note to Power Coater

Note to Power Coater

Installing the New Races and Bearings

Here’s the picture of the swing arm after powder coating.  The soup can sock seemed to keep the universal joint from being bead blasted.

Powder Coated Swing Arm

Powder Coated Swing Arm

I washed the swing arm thoroughly to remove any residual debris from the bead blasting.

I cleaned up the power coat over spray from the arms that hold the bearings.  One arm was fully coated inside and the other had minor over spray. That’s my fault as I should have put a masking tape note over them as I did on the rear drive gasket surface. No worries. It’s easy enough to remove the powder coating.

Powder Coat Inside Swing Arm on Drive Shaft Side

Powder Coat Inside Swing Arm on Drive Shaft Side

I use a sanding drum on a Dremel tool and then follow up with 600 grit paper so the inside surface is smooth and shiny.  It is easier to drive the race in when the inside of the arm is smooth and clean.

Dremel Sanding Drum and 600 Grit Used to Remove Powder Coat

Dremel Sanding Drum and 600 Grit Used to Remove Powder Coat

The shock side of the swing arm has a cover plate that retains grease but the drive shaft side does not. Here are the new parts in order of assembly, top to bottom, inside to outside, with the drive shaft side parts on the left and the shock side on the right.

Swing Arm Bearing Parts-Top to Bottom, Inside to Outside

Swing Arm Bearing Parts-Top to Bottom, Inside to Outside, Left is Drive Shaft Side, Right is Shock Side

I started on the drive shaft side. I put the races in the freezer for an hour to shrink them. I put some engine oil on the outside of the race and use the Cycle Works aluminum block to drive the race into the opening keeping it parallel with the sides of the hole.  The race wants to rock side-to-side when it starts, and I found tapping the sides of the race, going around the circumference with a soft mallet, helped seat it squarely in the hole before driving it in.

Race, Aluminum Block and Engine Oil

Race, Aluminum Block and Engine Oil

Using the flat side of the aluminum block and a hammer, drive the race into the arm until it’s flush with the top of the arm.

Using Cycle Works Aluminum Block To Drive Race on Swing Arm Side

Using Cycle Works Aluminum Block To Drive Race on Swing Arm Side

Race Flush with Swing Arm

Race Flush with Swing Arm Tube

Then, using the shorter side of the aluminum block, drive the race all the way into the arm until you hear it ringing indicating it is seated.

Using Aluminum Block To Drive Race to Bottom of Hole

This is the shock side arm cleaned and sanded with 600 grit wet paper.

Shock Side of Swing Arm-Hole Clean & Polished

Shock Side of Swing Arm-Hole Clean & Polished

The cover plate is indented and goes into the bottom of the tube and the race sits on top of the plate on the raised edge.

Shock Side, Grease End Cap Orientation

Shock Side, Grease End Cap Orientation

The cover slides in easily so you don’t have to drive it in.

Grease Cap Installed on Shock Side

Grease Cap Installed on Shock Side

Just as you did on the drive shaft side race, use the flat side of the aluminum block to drive the race flush with the top of the arm and then use the short edge to drive the race deeper until it bottoms out on the top of the grease cover.

Shock Side, Bearing Race and Grease Cap Installed

Shock Side Showing Bearing Race and Grease Cover Installed

I use NLG2 EP (Extreme Pressure) red grease and hand packed it into the bearings. I didn’t use my pinkie this time, but did wear my formal black gloves when I inserted the bearing into the race.

NLG2 EP Red Grease

NLG2 EP Red Grease

Greased Swing Arm Bearing

Greased Swing Arm Bearing

Swing Arm Bearing Installed

Swing Arm Bearing Installed

Next up, install the dust covers and sleeves.  The swing arm pivot pin slides through the sleeve and then inside the bearing.  I’ll cover installing the swing arm pivot pin when I write up installing ]the swing arm in the frame.

Bearing Dust Seal

Bearing Dust Seal

The sleeve goes under the rubber seal of the dust seal with the wider flat, or hat, of the sleeve against the face of the bearing. You can insert the sleeve after the dust seal is installed and it will look like this.

Dust Seal with Sleeve Inserted so Flat of Sleeve is Under the Seal

Dust Seal with Sleeve Inserted so Flat of Sleeve is Under the Seal

Use the flat side of the aluminum block and a gentle tap with a hammer to drive the dust seal in until it is flush with the top of the arm.

Driving Dust Seal with Aluminum Block

Driving Dust Seal with Aluminum Block

Then, push the sleeve through the rubber seal in the dust cap so it’s centered in the dust seal and the hat is completely under the rubber seal.

Dust Seal with Sleeve Installed

Dust Seal with Sleeve Installed

All done. After powder coating and new bearings, the swing arm is ready to install in the frame.

14 thoughts on “33 BMW 1973 R75/5 Remove & Install New Swing Arm Bearings

  1. Pingback: 1973 BMW R75/5: Replace Swing Arm Bearings & Powder Coat | Motorcycles & Other Musings

  2. Hey Brooke,

    I was wondering about your swing arm powder coating. I noticed you decided not to remove the drive shaft before sending it out. Are you concerned about how the heat involved w/ the powder coating will affect the bearings inside the drive shaft?

    Thanks,
    S

    • Hi Seth,

      Thanks for coming by and looking at the project. The powder coating process heats the parts to 350-400 F or so for 20-30 mins to melt the coating. There are no rubber parts in the swing arm U-joints and they are lubricated by the gear oil. So, I don’t expect any issues with this approach. To remove the drive shaft from the swing arm is not straight forward due to the high torque on the nut and the interference fit between the shaft and the coupling to the rear drive unit. That’s why I decided to keep the shaft inside the swing arm and protect the U-joints from the powder coat material.

      I’ll get to find out if there is any problem when I get the bike on the road (it’s still sitting waiting for me to finish the new paint job), but I don’t expect any difficulties.

      Best.
      Brook.

  3. Thanks for the response and the SUPERB write up of your project. You’ve done a fantastic job compiling all the information out there for these bikes. I’m tearing apart my /5 as we speak and I’ve enjoyed following your progress.

    cheers,
    S

  4. Thanks for taking the time to document how you did this. I’ve got my /5 blown apart an was trying to remove the bearings to powder coat the swing arm as well. The clymer manual is very vague on this process. I also decided to leave drive shaft in. Waiting for the puller to come from cycle works. Probably would have gave up on this part if I didn’t come across this. Thanks again.

    • Hi Chris,

      You’re welcome and I’m pleased my work is helping you complete yours. It’s great to hear about another airhead getting ready to go back on the road.

      Best.
      Brook Reams.

    • Hi Chris,

      I didn’t remove it, but I should have. I covered it with a layer of duct tape, but the bead blasting dulled the black paint on the plate.

      To remove it, you remove the steering stem. I believe you can use large screw driver and push the end of the rivet out from inside the steering stem tub. Then you can grab the head with channel lock pliers and pull them out. If that doesn’t work, try grinding the ends off inside the steering stem with a Dremel tool and a grinding stone bit. New rivets are available from BMW and from Hucky’s (http://www.bmwhucky.com/).

      Hope that helps.

      Best.
      Brook.

  5. Hi there,
    on my R100/7 (1977) is rear wheel off the center around 10mm against sub frame center to the left. Any idea how to adjust, or its just factory setting? Thanks for any help.

  6. Hello Brook,
    Let me just start with a big thank you for your fabulous blog. I’m refurbishing my first motorcycle, a 75 R90/6 and your blog has been amazingly helpful.
    I have finally gotten the frame free and intend to powder coat it and the swingarm.
    My question: Since I intend to replace the races in the frame and the swingarm, it seems more logical to leave them in for the powder coating process and then remove and replace them after. Thereby, not exposing the new races to the powder coating temperatures and blasting. Does this logic match your experience?

    • Hi Mike,

      Sure, that makes sense to me. That said, you should tell them to plug the hole the bearings go in anyway. Either way should be fine. Either approach avoids having the outer race exposed to 400-425 F temperatures, although I don’t think that would hurt the outer race.

      Best.
      Brook.

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