<VV> Re: SPEEDOMETER ISSUES

[N2VZD at aol.com]

if the odometer is set up it is time to replace it.  i have repaired them but 
it aint worth it!  . it puts a load on the whole system when it is set up 
because the little tiny bearing in the magnet is probably as worn as the rest  of 
the unit. the magnet is probably not running true so the speed cup may be 
touching it at times also causing the jump. it runs on a broze bearing in the 
frame , and is staked together at a special tolerance. if you are very very lucky 
you may be able to lube the cable (i use a silicone grease that is not 
affected by "normal" temps) and replace the odometer. i think someone put the 
instructions on how to set the mileage in the tech guide. you can get odometers new 
or check the yards for low mileage gm speedos from the 80's to use for parts.  
if you dont have a speedomter calibration machine and a magnatizer / 
demagnatizer  available nearby do not disturb the needle on its fragile post. you can 
tip the face carefully witout removing the needle to change the odometer..  i 
still hope to put together a presentation tape or cd sometime on the speedos 
and hot to repair them or what to look for. i repaired them for a large company 
under gm warranty back in the late 60's and early 70's. scarf up any gm good 
speedos for parts because the frames etc are getting hard to find in good 
condition.  earlies are 1000rpm's per mile  lates are 860rpm's per mile as i 
remember...they can be changed with the right tools...   spyders had a metal second 
worm , others had a plastic which will bend causing a "jump" when the 
odometer is setup. 
if you are not good with small tight work send it out for repair.
this is a "condensed" explaination.
regards, tim colson