All 140 series Volvos (without overdrive) equipped with the M40 gearbox use SAE 80 gear oil, or if none is available, SAE 30 engine oil. All 140 series Volvos with overdrive and all 1800 series Volvos equipped with the M410 gearbox use SAE 30 or SAE 20W-40 engine oil. Model 164 Volvos, without overdrive, and equipped with the M400 gearbox use SAE 90 gear oil or SAE 40 engine oil.
1975 240 series Volvos equipped with the M40 transmission use SAE 80W/90 or SAE 80/90 gear oil, while all 1975 240 series Volvos equipped with the M41 overdrive transmission use SAE 30 or SAE 20W-40 oil.
On a number of 1976 240 series and 260 series models equipped with the M45 transmission and the M46 overdrive transmission, the transmissions are filled with SAE 80W/90 or SAE 80/90 gear oil, while all other M45 and M46 transmissions (used on 1976-88 models) are filled with Type F or Type G automatic transmission fluid. You are reading that correctly; automatic transmission fluid in a manual (stick shift) transmission. An easy way to tell if the transmission uses gear oil or ATF is: on ATF filled transmissions, the figure eight shaped flat casting located at the filler plug is stamped "ATF-OIL" in white. Do not attempt to use gear oil in these transmissions, or vice versa. The M47 5-speed transmission introduced in 1987 also uses Type F or G fluid.
At 6000 to 7500 mile (9662-12,077 km) intervals, the fluid level should be checked. After making sure that the vehicle is standing on level ground, unscrew the filler plug and check to see that the fluid level is even with the bottom of the filler plug hole or just flowing out of it. Top up, as necessary, with the recommended gear oil.
On vehicles with overdrive units, the overdrive gears are lubricated by the transmission oil; no separate filler plug is used.
DRAIN AND REFILL
See Figures 1 and 2
Once the transmission has reached operating temperature (after being driven 5-7 miles or 8-11 km), the oil may be changed.
- Place a drip pan beneath the vehicle, then remove the drain plug and the filler plug. On vehicles equipped with overdrive, remove the six bolts and cover, allowing the unit to also drain.
- At this time, the pre-filter and fine filter must be removed and cleaned in solvent. To remove the fine filter, Volvo special tool no. 2836, or an equivalent removal tool, must be used to unscrew the filter housing. After blowing the filters dry with compressed air, install the fine filter in its socket with a new seal. Tighten the plug for the filter housing with special tool no. 2836 or similar to 16 ft. lbs. (22 Nm). Install the pre-filter and the cover with a new gasket making sure that the magnet is in place. On overdrive units from 1983, the strainer is external; it will come off with the cover and can be easily cleaned.
- Install the drain plug.
- Fill the transmission to the filler plug opening with the proper oil, then install the filler plug.