| Hi Fred,
I had this happen on a Speedometer that I Rebuilt.  Not a very good job,
was it.  I actually adjusted the disk too close and it was hitting the
indicator plate.  I would say there is a problem inside the unit.  Take
it to a shop, don't even try like I did to repair it.  Took me almost a
month to figure out what was happening.
Rick
52 MGTD, 74 B, XJ12C, & Puddles (60 Frogeye) 
Fred Krampits wrote:
> 
> Unfortunately I was stopped at a light, my flaky speedometer had the
> needle fall forward at about 50 mph and stayed there for a few minutes
> before going back to 20. What is interesting is that the mileage is
> increasing correctly on the odometer, but when driving it goes from 40
> to 70 to 50 to 60 without any real change of speed. It was humourous to
> see it pegged out at 100.
> 
> Fred
> 1963 Midget MK I 1098CG
> A real Mean Machine
 |