hi sages- have experience with 3 manual od trans. current m47 five speed and dodge 4speed od. both are fully manual shift(no electrical semi automatic shift into od). currently have a 92 245 wagon. top gear in these 2 was od .73 to 1 in the dodge and i think .80 to 1 in the m47 volvo 245. my question is about the m46 od in older volvos which i think the m47 replaced. this one sounds like the borg warner trans in common use in chevrolets and fords and chryslers in 40s- 60s american cars. this trans would be manually shifted through 3 gears and if the t handle under the dash was pushed in for od then at 28 mph a distributor interrupter sensor would interrupt the coil and send a message to a solenoid on the side of the trans which would shift it into od. the trans would free wheel up to 28 mph which had two interesting effects:1. once rolling you didnt have to use the clutch to upshift or downshift just back off on the accelerator 2. you could actually obtain 6 forward speeds with these 3spd standards by skillfully handling the t handle , clutch and column shift. low demand and some unreliability with the electrically actuated od engagement killed them in american cars about 1967. had a 63 chevy with 3 spd od set up exactly this way. did the m46 od operate this way and was it a borg warner trans. think gm owned borg warner. hope you liked this trip through ancient history. thanks tons older sages who remember these transmissions oldduke