I finally got this old car going and have found the overdrive does not engage. When I slide the switch the OD light on the dash lights. I checked the voltage at the solenoid and got 12v when the OD was switched on and 0v when it was switched off. I checked the fluid and it was low. I drained the fluid from the gearbox and the overdrive and refilled with Castrol ATF Type F. Did about 10 minutes on the freeway at 60MPH and there was still no engagement. I had someone move the switch for me while I put my hand on the solenoid, and did not hear or feel anything. The PO said the OD was operational last Fall, but PO’s say the darndest things. I saw one website that said you should hear a solid engagement, and another that said you may or may not hear anything. Should I just order another solenoid, or can it be repaired?

Vehicle: 1976 Volvo 245 DL M46 Transmission