The five speed transmission of the BMW 2-valve boxer has one weakness in particular that can really cause you problems, suddenly and without warning, when you least expect it.
The shifting mechanism inside the transmission relies on a small spring to maintain contact with the shift lever and this spring has been known to break. When the spring does break, the transmission is stuck in whatever gear was engaged at that time. If you are stuck in first, you can keep going, but slowly. If it's fifth gear, you'll be OK at highway speeds but once you need to stop, good luck getting moving again without smoking the clutch. It's also possible for the bike to be stuck in neutral, and in that case, pushing your bike is pretty much the only option. With five gears plus neutral, there are 6 possibilities and the odds of winding up stuck in a usable gear carries the same odds as rolling a die.
The symptom of a broken spring is that the gear shift lever moves up and down freely, without resistance and springs back to the center position. Should this ever happen to you and you have the GearShifter along, you will be able to make it home or to the repair shop under your own power, without any assistance or expensive towing charges. The GearShifter is a tool, made of top quality stainless steel and it's small enough to fit in your standard tool kit. Like insurance, it's one of those things that you hope to never need, but if you ever do, you'll be happy that you made the investment.
Here's how it works in a nutshell: You remove the transmission oil fill plug and insert the tool to temporarily restore contact between the shifter pawl and the shift mechanism. The tool will allow you to select the gear of your choice, based on your current conditions in just a few minutes. Should conditions change, you can stop once again and quickly select a different gear. This tool will not repair the broken spring, but it will allow you to "limp" home or to the repair shop under your own power. The GearShifter is supplied with detailed, step by step instructions, printed in full color on high quality paper. You'll want to be sure and carry the instructions with you along with the tool.
The GearShifter is made in the German State of Bavaria and patented. It will give you peace of mind to know that you are ready for the almost inevitable spring breakage, if and when it should occur. If you carry tools for roadside repairs or to fix a flat tire, then you should also have the GearShifter along because the odds are against you never experiencing this failure!
All five speed 2-valve Boxer Transmissions (1974-1995)