Volvo Repair: Speed sensor ... in auto transmission, speed sensor, bellhousing

Question
I am driving a 940 Turbo 1994. I would like to know what is the function of the speed sensor on the Auto Trans? Because from what i know, the gear change is govern by fluid pressure.

i am having higher than normal RPM ie 3000 rpm on cruising a speed 110km/h ... in the past it is only abour 2500 rpm on the same road.

shift from 1-2 is bad, after a long rest, it is difficult to get it to shift from 1-2
ATF is new. I am using Elf Dex III

thanks


Answer
there is no speed sensor on the transmission.the behind the cylinder head near the top of the transmission bellhousing is engine RPM sensor.I would be sure it is going into overdrive just because the light works does not mean it is going into overdrive it could have a bad overdrive solenoid or a blockage in the transmission orifice where the solenoid bolst on the trans.

Rege