Lincoln Repair Questions? Ask a Mechanic for Answers ASAP
This is most likely caused by the vehicle speed sensor giving off a poor signal. The speed sensor can be replaced to help remedy the problem. If the speedometer doesn't work at all it is likely a wiring issue.
Does yours not work at all or it is just not at the right speed?
I can send a diagram to show how to replace the speed sensor if you would like to replace it yourself.
Here is ford's listing for the speed sensor replacement.
I just wanted to see if you needed any additional information. If I have been of some assistance I would appreciate a positive rating. Thanks!