<VV> GM sspeedometers partial over veiw

N2VZD at aol.com N2VZD at aol.com
Sat Jun 3 18:02:13 EDT 2017

I went to the GM  tech center  for my job  back in 1968  for 2 weeks of 
training on speedometers , tachometers , and cruise units put on  by AC . I 
worked at the GM warranty repair center in Syracuse NY for @15  years.
 One thing I still remember is to avoid "pulling or prying on " the  Speedo 
needle , it messes up a friction damper disk on the pointer shaft.
 On most GM Speedos you just twist the needle GENTLY backwards against  the 
speed cup stop. To reinstall it , place it on the stem in correct position  
and gently tap it once.
  As far as calibrating , To be sure , you need a machine , and a  
magnetizer / demagnetizer to get the balance between magnetism  and  force of the 
hairspring.  There is a procedure to adjust the  play of the main bushing 
also. Unless it is really worn , it can  be tightened  up acceptably , but you 
have to tear it all the way  apart to do it .
 I still own the equipment to work on them , but am busy with other  work 
most of the time.  I am out of NOS parts , but kept a few used speedos  and 
tachs just in case.
There is more to doing them correctly than meets the eye , so that may  
explain the price from the old timers that know how to do it right the first  
time. One wrong move can damage odometer , or face etc. 
Regards, Tim Colson

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