Well, I had a little light bulb out behind the odometer so I removed the speedo cluster to fix it. Now for some reason my speedometer needle drops everytime I shut the truck off. It drops everytime until it can't drop any further, making it read about 12-15 mph too slow. Is there something I should have done before taking it out (unhook battery)? When unplugging the cluster, then plugging it back in, it goes thru what I would call a recalibrating sequence where it vibrates and hums for about 5 seconds or so then drops the needle too low. I can move the needle manually where it belongs, but everytime I shut off the power, it drops after about 30 seconds. Have I stretched or broken a spring somewhere or what? Thanks in advance...