Volvo Repair: VOLVO 89 NON SPEED, solenoid, overdrive

Question
I bought VOLVO 89 I made the required tune up, but when I drive it on the free way with D gear and reach the speed 55-60 miles the engine give high sound I think the gear didn't change to the faster speed, how can you help me and what type of maintenance need to be done. thanks .

Answer
Sounds like your overdrive solenoid isn't functioning.Make sure relay is working (button on shifter) If it lights when you push the button and then turns off again when you push it again thats good. You should be able to hear a clicking sound from the transmission when you push the button. No click, check wiring and replace solenoid