Darryl.Richman's picture

One of the places I had never been on this bike was the transmission. Oh, sure, I had taken the top off before, but that's not a big deal. I wanted to go through it because it whines pretty loudly, especially in 3rd gear, and mostly because I wanted to be sure that nothing was going to pop up and surprise me on this trip.

There was nothing too terrible to find, fortunately. The transmission is a bit of a Chinese Puzzle; neither Brent nor I is still completely certain exactly what gyrations are necessary to free and replace the output shaft. It kind of hangs up on the shift fork and 1st gear, which is in back (see pictures below) and a bit wedged into a niche in the case. If you fiddle with it long enough, you can get it to go where you need it.

I took the time to clean up 2nd gear on the output shaft. This transmission has constant mesh gears for 1st and 3rd, but when you move the big shift lever, you're actually pushing 2nd gear around on the output shaft. This means that every time it goes into 2nd, the gears grind a bit as a prelude to meshing. 2nd didn't look bad, but there was a little bit of wear, and I used a diamond file to clean off the rough edges.

The box got new bearings and new seals, and now it doesn't weep nearly as much as it did before. The bearing on the rear of the input shaft was a neat old roller bearing. The rollers were captured by a brass ring with cutouts alternating on one side and then the other of the ring. The guy at the bearing house had never seen one like it, and because it was stamped "Germany", I think it must be a prewar item. (German items made postwar are generally stamped "West Germany" up to 1990.) Brent also shimmed up the box so it wasn't so loose.

Maybe it's a bit quieter now, but it does still whine in 3rd. Must be the straight cut teeth.

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German transmission ingenuity

Transmission guy's picture

Thanks for showing pics of this interesting transmission. As you said, to the untrained eye transmissions do look like a Chinese puzzle, and now that you've put some time in this one, you're probably that much more experienced and wiser. Hope your motorcycle lasts a very long time.

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