Only clean, new SAE 80 or 90 weight transmission lubricant should be used in the manual transmissions.
Before checking the lubricant level in the transmission, make sure that the vehicle is on level ground. Remove the filler plug (located on side of transmission). The level of the lubricant should be up to the bottom of the fill hole. If lubricant is not present at the bottom of the fill hole, add SAE 80 or 90 transmission lube until it reaches the proper level. A suction gun or squeeze bottle is used to fill a manual transmission with lubricant.