Can you change the gear oil in a manual transmission if the fill plug will not loosen up?

Answer 1

Well this can be re-filled by removing the gear shifter; simply remove the plastic cover then remove the rubber boot at the base of the shifter,then remove four 13mm bolts that hold the shifter in place. Slide out the shifter then slowly pour your gear oil in the opening. Be patient because it fills slowly. Replace everything you just removed. thank you for your comment but a 300zx has a linkage between the shifter and the transmission. in other words the shifter is not mounted into the transmission itself. i did find another way. i removed the exhaust and the drive shaft to get to the output shaft end of the transmission. i had a gallon jug of gear oil with a pump that mounts on the bottle.i cut the open end off of an advil bottle and poked a hole in the bottom just big enough for the tip of the hose that is on the pump. the reason i chose the advil bottle is because it is the same diameter as the yolk on the driveshaft. i used electrical tape and went around the hose and the bottle until the hose was good and tight. then i just shoved the open end into the back of the transmission and pumped away. i used 3&1/2 quarts of oil. when i pulled the hose out a small bit of oil leaked back out and i had a bucket ready underneath to catch the excess oil. then i just put everything back together.