Speedo Problems

Don't know what causes this but I hope someone out there knows. The speedo in my 91 metro will go crazy in the morning. It will bounce and go all the way up to 85 mph. I don't think it has ever been there running right! LOL. In the afternoon, it will work right with no bounce. I think the cold weather might have some affect on it. Any suggestions?

The speedo in the ?92? on metros rides in a little "pot" of grease. If the grease dries out the speedo will start to read incorrectly, especially in cold weather. I have been driving with this issue for a couple of years and
the first cold day earlier this year almost got me a ticket (I passed a cop, in town, at about 15 miles above the speed limit. I will soon be removing the cluster to put new white face overlays on, and I am planning to use some AC Delco distributer grease to see if that will correct the problem. I will update the results here.

jon

Thanks for all the help. Will look into seeing if the grease is dried out or anything. It reads right as long as it is warm. thanks again.