Lucas Oil 10121 Synthetic SAE 75W-140 Gear Oil, Red, 1 Quart (32 Ounces). Manufacturer Part Number: 10121. OEM Part Number: 10121. Manufacturer: LUCAS OIL. Lucas SAE 75W-140 Synthetic Gear Oil is a non-foaming, super slick, long lasting lubricant designed especially for heavy duty or high performance applications where regular gear lubricants just aren't good enough.