Manual Transmission Fluid Service
Manual transmissions used in most Volvo cars from 1961 to 1995 have two large plugs on the driver’s side used for draining and filling the transmission.
To drain, remove the lower plug (as well as the inspection plate on OD models) and drain into a suitable catch pan with at least a 1 gallon capacity. Clean the OD filter screens, re-install the drain plugs and OD inspection plate, remove the upper plug and fill with the appropriate fluid until it begins to pour out of the filler hole. Oil should be changed about every 30K miles.
The M40 takes .8 qts of 30 wt, the M41 uses 1.7 qts of 30 wt, the M45 uses .8 qts of Type F automatic trans fluid, the M46 uses 2.4 qts of Type F and the M47 uses 1.6 quarts of Type F.