High mileage Subaru 2000 Outback Legacy. While driving it over the weekend I experiences an issue with the dashboard gauges quitting accompanied by a hard thump in what I am assuming is the transmission. The gauges (speedo & Tach) drop to zero followed quickly with a thump in the transmission. It will then right itself, only to repeat, over and over.

 

I was on my way to ND from Idaho, got a 100 miles up the road when this happened. Limped home and it quit doing it for the last 20 miles or so. Now I can't get it to do it again, and error code reader comes up with nothing...

 

Any suggestions?

Kinda sounds like the car was losing electrical power altogether.

Check and clean battery connections.