How to fix worm screw and get mileage counter working

[Moyners]

Hello,

someone did kindly describe how to fix this before - sadly it was in response to a 'wanted' message when I thought I needed an instrument cluster and posted seeking a replacement one - that message is now long gone and I'm about to ask Graham at the garage to see if he can understand what was needed and do it for me (among other things)

Could that kind person or some other font of knowledge describe what to do in a way that I can relay - i think I remember a dab of glue being involved.

Thanks millions

Paul

[AdrianC]

Of help?
https://club8090.co.uk/forum/viewtopic.php?f=39&t=108512" onclick="window.open(this.href);return false;

[California Dreamin]

The two times that I've used glue to fix this issue neither time lasted more than a few weeks......I think if I have another one to repair I would look at trying to stop the trip 'spindle' working it's way out of it's mount...maybe make some sort of stop plate. Not really a cure but could work.

Martin

[AdrianC]

I think if I have another one to repair I would look at trying to stop the trip 'spindle' working it's way out of it's mount...

<thinks>
This was a common problem on Saab 900s, too - and the generally accepted cause was resetting the trip meter whilst the car was moving, causing different load directions on the plastic gears. I wonder...

[California Dreamin]

From memory I'm sure the plasting worm gear itself is the stop (the part that stops the the shaft moving) it's tight interference fit to the shaft resisting the natural lateral forces put upon it by the action of the meshing gears. From my understanding, ageing makes the plastic material become brittle and as a consequence of the internal forces (interference fit on the shaft) the gear developes a hairline crack. Whilst there remains adequate friction to drive around the gears, unfortunately now the lateral forces work the gear up it's supporting shaft until that shaft falls out of it's mount.
Hope this makes sense.
Without the benefit of having a speedo to hand I was wondering if using the innards from a terminal block connector on the shaft to stop the gear creep would be an option (cut off the plastic outter and thread the connector onto the shaft..I'm guessing the gear would need to be removed as well)

http://www.google.co.uk/imgres?q=termin ... ,s:0,i:155" onclick="window.open(this.href);return false;

Martin