1983 BMW R100RS Rebuild Transmission

This is the second time I have worked on rebuilding an airhead transmission. That should make it clear that I am an amateur, not a professional, when it comes to doing this work. I would not attempt to rebuild a transmission unless I have access to experienced, long time, airhead mechanics. I’m very fortunate to have access to three of them. And, I plan to continue rebuilding transmissions on my own projects, so the considerable investment in tools will get amortized over the future projects.

NOTE:
I would not recommend that you rebuild your transmission unless you have completed multiple bike rebuilds, have invested in precision measurement tools and specialized transmission tools, and expect to rebuild multiple transmissions. The cost and risk are too high if you just plan to do one transmission. I would recommend you have your transmission rebuilt by a reputable builder such as Tom Cutter at Rubber Chicken Racing Garage in Pennsylvania, Matt Parkhouse ([email protected]in Colorado, Bob Clement at Bob’s Motorwerks ([email protected]) in Montana, and Bud Proven at The Nickwackett Garage in Vermont.

This transmission has over 83,000 miles on it. That said, it was in good condition when I had the parts inspected by an airhead mechanic. So that’s a good thing.

I wrote five documents showing how I do the work.

And, I shot five YouTube videos summarizing the work in each document.

VIDEO: 1983 R100RS Disassemble The Transmission

VIDEO: 1983 BMW R100RS Rebuild Transmission Shift Cam Assembly

VIDEO: 1983 BMW R100RS Rebuild Transmission Input & Intermediate Shafts

VIDEO: 1983 R100RS Rebuild Transmission Output Shaft

VIDEO: 1983 R100RS Assemble Transmission

This is what I started with:

Transmission Before

Transmission Before

Transmission Before

Transmission Before

Transmission Before

Transmission Before

Transmission Before

Transmission Before

And this is what things looked like during disassembly.

What's Inside The Transmission

What’s Inside The Transmission

Shift Cam Assembly Parts

Shift Cam Assembly Parts

Input Shaft Parts

Input Shaft Parts

Output Shaft Parts

Output Shaft Parts

Intermediate Shaft Front Bearing Removed

Intermediate Shaft Front Bearing Removed

And this is the final result.

All Done-Red Tape Means "Needs Attention" As In Gear Lube

All Done-Red Tape Means “Needs Attention” As In Gear Lube

All Done

All Done

3 thoughts on “1983 BMW R100RS Rebuild Transmission

  1. Another great set of instructions and videos, but I will heed your advice when the time comes and send it to someone that has the knowledge and the skill. Thanks again.

    • Hi Saunders,

      You’re welcome. And your decision is one reason I published this material. When you can review a procedure and the tools necessary for doing precision work, you can make an informed decision about whether you should try to do the work or you would be better off to hire an expert to do it for you. There are a number of tasks on my projects that I hire the experts for.

      Best.
      Brook.

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