I have a problem with my car’s transmission slipping going from second to third gear. I have taken it to my mechanic that has over 20 yrs experience and he drove it 15 miles and nothing happened. His transmission specialist drove it 50 miles and nothing happened. When it slips from second to third I notice the speedometer goes crazy. Goes from 0 to 30 back and forth like a ditzoid.
I drove it to church which is 17 miles and it drove fine. The trip back home it had the same symptoms after 10 miles.
If the Vehicle Speed Sensor (VSS), which is attached to the transmission, is malfunctioning it could explain both the speedometer and the transmission, especially since they are happening at the same time.
Did you tell your mechanic about the speedometer?
Yes, I just told him today. I wish I told him earlier. He is looking into it.