2nd Gen Non-Engine/Transmission speedo acting up

[datablitz]

my speedometer looks like it is actin correct, but it is usually %100 too high... . when crusing about 50-60 the speedo reads between 90-120mph... . the trans is shifting correctly, just the speedometer is wrong, what could be causing this

 

[Dennis Garrett]

Follow the speedo drive cable back to the transmission tailshaft. It should have a speed sensor there, make sure it's tight, and make sure the electrical connection is clean & tight too.