020 Transmission Gear Oil

This one is pretty easy. My transmission is a 4K close ratio transmission, and I want to keep it alive. So - before my big roadtrip - I am changing the gear oil.

Most of you will want to use a nicer kind of gear oil than I did - such as Redline or Royal Purple. But I am happy with Castrol 80W-90 for my transmission.

You will need the following to do this...

• 17mm inside Socket
• A Drain Pan
• 2.1 Quarts (1.9L) of 80W Gear Oil - You can buy a jug and share with a VW friend!
• Some kind of cleaner
• Transmission Funnel - the kind with the flexible extension on it

Special thanks to forum member Southcross for helping me on this technote. We are doing this to his car (81 Rabbit S) and my car (84 Scirocco 8v) this weekend. My car has a 1.8 8v (JH) with a 4K transmission and Southcross's car has a 1.7 8v (EN) with an FF transmission.

Drive your car around a bit to warm up the transmission oil - so it all runs out quickly. Park and then crack the lug bolts for the driver's side front wheel - we'll be removing it later. Jack up the car on the driver's side. Get it really high - as high as you can. You will see why later in this technote. The point is to make the car as tilted as possible.

Put a jack stand under the control arm mount so the car doesn't crush you! Get out the drain pan and get it ready.

The tool you need to take off the drain plug and the fill plug is a 17mm hex thing that sticks out. You should be able to get one at your local auto parts store for less than six dollars. However - you can ghetto rig this job - use a 17mm bolt to get them out - an old lug nut is perfect! Ah the wonders of lazy tools!

So - next is to get the drain plug out. It is toward the back of the transmission on the back part where the axles come out (the differential). Clean the area off of grease and road grime - I used carb cleaner. Get your oil pan ready, and crack the bolt and loosen it out. BE CAREFUL - this stuff is hot!

When It's draining - note the color of the oil - it will tell you the condition of the transmission. Mine was brown and nasty. Southcross's was nice and clearish. So clean in fact - that it looked like it was the wrong kind of oil. My old Scirocco's transmission oil was black and metallic - signs of a dying transmission.

Remove your driver's side wheel so you can get to the fill plug on the side of the transmission. Take it out - it's the same size as the drain plug. Look inside - you can see your gears!! Rig up your transmission funnel - you can tie it to your strut spring.

When your car is done draining (takes a while) - you can put the drain plug back on. 17mm. Mine still stuck out a couple of threads when it was all the way in. Make sure you give the plug a good cleaning - you don't want any dirt going into the transmission!

Next you have this nice hole to fill the transmission with. The car is jacked up so much so we can get ALL of the fluid in the hole - no speedo cable trick for us! Carefully measure out the 2.1 Quarts of transmission fluid. Some car's filler plugs are too low to fill the whole capacity in the transmission. Tilting the car with the jack solves this.

Now - Fill 'er up!! Goes slow - the oil is thick - be careful not to spill any. Make sure everything is still clean too.

If you can't get all 2.1 quarts in - you need to jack up the side of the car a bit more. After you're done - Put the cap back on. Make sure everything is tight - and put it back together. Put your wheel back on, let the car down, and torque the lug nuts.

You now have a happy transmission!

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