I've got an odd issue. When I turn my car on, the speedometer needle sits below the 0. It moves normally but it's at least 10 MPH off (on the low end) at speed.

It started when we took my transmission off to fix the clutch vibration. There was nothing odd about the process, we didn't drop the transmission or bang it on anything, and sensors were plugged back in the way they were before.

I jacked the car back up last night and got underneath it again and looked at the sensor plugs and everything looks fine. Any ideas?