I also had an 84 with an odometer that had crossed the 300K mark. It would slip miles in the hot days, just a bit, making me think the gas mileage was poor. The lambda sond reminder box was already disconnected (and already discovered on a previous 83), so I had to dig into the gauge to find the same gear Dave Barton mentions slipping on the shaft - the pot metal one.

Instead of re-staking the pot metal like he did, I reversed the shaft, because it was obvious to me the shaft had worn. Once fixed it made it the rest of the way to its 375K rust demise without giving me further trouble.

I used the trip meter to keep track of fuel economy. Since I'm about run out of little plastic junkyard gears for the later models, I've stopped resetting the trip odo at every fill-up.




--
Art Benstein near Baltimore

Those who get too big for their britches will be exposed in the end.