Trip Reset Removal

I have a problem with the tachometer on my 79 A1 and need to take the instrument housing apart. However, I am having trouble trying to remove the trip reset knob. The manual (and several posts on this site) suggest all you need to do is to turn the knob clockwise and it will unscrew. Unfortunately, the knob just seems to turn and turn with only a slight click each revolution. I have tried "shocking it" to try and free the thread but nothing seems to be working - anyone else had this problem? - and yes, I am trying to turn it clockwise. Thanks!

I just removed mine from my own bike last weekend, and it came out exactly as the manual states............by turning it in the opposite direction to resetting it.
The threads inside the knob are very fine so it did take a good few turns before it was obvious it was coming off its shaft.
As its a delicate part of the bike, its might be worth applying a little warm air / heat to it with a Hair Dryer first just to make the plastic expand and a little softer.

Pete F
UK

Thanks! - I hadn't thought of using some moderate heat - good idea. Is the thread formed in the plastic material itself or does it have a metal insert with the thread inside? I can't tell from the few pictures I can find.

Looks like no metal insert in the knob on mine. There are threads on the metal shaft of the reset part though.

Hi Neville, just went to the garage to check, on my bike the knob has a left thread and when i try to unscrew it there is a spot when all the numbers come to zero, that's where it started to turn on the shaft. There is no metal insert in the knob.





daro

Thanks Daro, very helpful - just one more question - does the centre hole on the outside of the knob go all the way through to the threaded part? Just wonder if I can spray something in there to help loosen up the threads?