348 speedometer help

I have a 94 348, and everytime it is driven over a hard bump the speedometer (cluster) looses power. Can it be that there is a bad connection on the transmission and if so where should I look for it. Recently I had some trans. work done, so maybe the shop didn't connect it well. Thank you for any help.

I would pull the instrument pod and have a look at that back of the connections first. There are two screws on the bottom corners of the pod. Remove those and then lift it straight up. There is nothing else holding it in place.

As for the tranny sensor. There is a speedometer sender on the bottom left side of the trans. You can look under the car and see it, just to the side of the shift cables. It could either be that they didn't connect it properly, or that there is a busted wire on it, or that the sender itself is actually bad. If the sender is bad you can change it yourself, but be sure to drain the gear box oil before you change it out.

Thank you ernie.