[W126 Coupe] How to fix flaky speedo needle????

[Dick Spellman]

I have a speedo needle that works perfectly at temperatures above 40 F.  
At temps below 40F (especially when sitting overnight) the speedo will 
run 60-70 MPH greater than actual driving speed.  After 5-10 minutes the 
needle simply drops to the correct speed and works perfectly once again.

Question how is this speedo made up for this year MB and what needs to 
be fixed, replaced or adjusted to clear this up?

Thanks in advance.

Dick

Problem is on an 86 300SE Euro(126 chassis) and odometer etc. work 
perfectly and independent of the speedo.