How to change your gearbox oil
Firstly you shouldn't need to do this very often. The oil is supposed to last the life of your gearbox. You would only want to do this really if it hasn't been done for a couple of hundred thousand kms, you've fitted a new gearbox, or you're having shifting problems with your gearbox etc.
Its extremely easy. Don't waste your money on an expensive gear oil pump like I did once upon a time. Buy a $2 piece of clear hose about 2m long.
You will need 80wt gearbox oil for the micra/pulsar gearboxes, I used Castrol VMX80 for now which is what Nissan recommend. You will need 2.8-3.0 litres of oil for a micra gearbox, or closer to 3.5 litres for a pulsar RS5F31A gearbox.
- First you will need to drain the gearbox. So you'll need a bucket.
- Put the bucket under the gearbox.
- Under the gearbox you will see a threaded metal plug thing that has a sunken square shape in it - that's the drain plug. With the bucket underneath this drain plug, undo the drain plug with the drive of a 1/2" drive socket, i.e. you don't need any fittings on the end of the socket - the socket itself undoes the plug.
- When its very loose remove the drain plug and let all the oil spew into the bucket. Go and have something to eat and come back in half an hour after every drop of oil has had a chance to come out - you don't really want to mix your new oil with the old garbage..
- Now re-install the drain plug into the gearbox. I don't know the exact torque figure its meant to be tightened to, but do it firm but not extremely tight, you definately do not want to strip it or the thread in the gearbox - so be careful not to overtighten this one.
- Now look around the front of the gearbox more, and you will see another similar plug to this one, however it takes a smaller 3/8" square drive to turn it. So with your 3/8" drive socket, remove this plug - this is the filler plug.
- Now, similar to the photo below, suspend the gearbox oil up high (I used a zip tie to attach it to the bonnet latch and hang).
- Put one end of the clear plastic tube into the gearbox oil bottle.
- Guide the other end of the tube inside the engine bay down in front of the gearbox and make sure it reaches inside the filler plug hole
- Then get back under the car and suck this end of the tube so that you syphon the oil out of the bottle and you see it starting to flow through the tube.
- Quickly insert the bottom end of the tube into the gearbox filler hole and make sure it will stay in there.
- Now you probably have another 10-15 minutes or so to do something. So just keep checking the oil level in the bottle until its emptied 2.8-3.0 litres of oil into the micra 1.3's RS5F30A gearbox. (I used 3.5 litres for my RS5F31A pulsar gearbox because its larger).
- When enough oil is into the gearbox, remove the clear plastic tube and re-install the filler plug!
- You're done!