[Tigers] Auto Meter Cobra Tach

[Rollright at aol.com]

Hello,
 
 

So, I get the new Auto Meter tach, get the Sunbeam face all redone by  Paul 
(beautiful job), get the paint to make the blue segment inside, and go  
done to my workbench in basement to take the tach apart to start the mods.
 
- I take the nut and star locking washer off the middle of the back of the  
case. Then nothing. I put some real pull on it and nothing.... like it  
doesn't come off that way.
 
There must be an easy solution to disassembly that I'm overlooking. 
 
Can anybody help here?
 
Jim  Armstrong
Mk 1A 382002083
LRXFE