'88 240 DL temperature gauge, temperature compendsation board, gauge needle position.

My odometer failed so while I had the instrument cluster out to replace the odometer gear (do search for odometer gear replacement) I did the recommended fix of the temperature compensation board.

My temperature gauge was shooting up to the red zone periodically and I read that it would do this due to a fault in the temp gauge that would be reset by tapping forcefully on the dash.

I suspect while tapping forcefully on the dash for the umpteenth time that I might have accelerated the demise of the odometer gear as it stopped working on the last dirve I "tapped" the dash.

After jumping the temp compensation board contacts the temp gauge was reading at 1/4 to 1/3 - down from the 9:00 tick mark I was used to when it was warm and connected to the temp compensation board.

On the way back from a recent 4+ hour trip to the beach (hot, steady 60 mph) the temp gauge went up to 1/8" above the 9:00 tick mark. The water and oil checked out positive and I noticed no change in acceleration or engine noise. I stopped the car to let it sit a bit and when restarted the needle went right back to above halfway immediately.

Any ideas what I might be looking for?

Thanks you.