B5 manual transmission fluid change

Difficulty: About twice as hard as an oil change (potentially messier, tighter quarters)

Necessary supplies:

• 3 quarts of tranny fluid (2.25 liters of 75w-90 is the factory spec. Redline MT-90 is the favorite among ClubB5 members. Check www.redlineoil.com/dealers.htm for local listings. Around $8.50/qt.)
• VAG tool #3357 (available from www.zelenda.com for around $35 shipped. It is a ½” drive “tamper-proof” Torx socket for the transmission case drain plug)
• 17mm allen wrench (available from www.grainger.com for under $15 shipped)
• Siphon pump with at least 2’ hoses (available at most auto parts stores for under $15)
• Oil drainage pan (10-15 qt. capacity, Walmart $5-$8)
• Ramps (recommended: Rhino Ramps, Walmart $30)
• Flathead screwdriver (for removing belly pan)

Optional supplies:

• 17mm boxend or open-end wrench (highly recommended)
• Rubber gloves
• Rags
• Q-tips
• Protective goggles

1. Do not attempt this procedure on a fully-heated engine. Drive the car around for about 3-5 minutes to circulate and warm the transmission.
2. Position ramps in front of tires and drive car gently up to the stop.
3. Leave car in first gear (or P) and apply parking brake.
4. Place a chock behind rear tire(s) (or brick, 2x4, etc).
5. Remove plastic underbody cover—there are two plastic screws in each wheel well, 4-6 more towards the center of the car, and a small nut front and center. All of the screws should come out after ½ to 1 full turn. Set the screws aside.
6. Directly behind the rear central belly pan screw is the transmission case. It is silver, with cooling fins running longitudinally down its surface. On the bottom is the #3357 Torx plug, and on the driver’s side you will see a 17mm hex bolt, which is the fill plug.
7. Always test the fill plug first! If you drain your tranny and then find out that your fill plug won’t budge, you will not be happy. It is positioned at a very awkward angle for the allen wrench, so try the optional 17mm wrench (attached to the allen wrench) to assist in the removal of the bolt. Be patient, and try to avoid rounding off the hex head.
8. Next, replace the fill plug halfway by hand. This will prevent the drainage from flowing too quickly (I learned this the hard way)
9. Position the oil drainage pan below the drain plug, and put on your goggles. Remove the drain plug and allow the old fluid to flow for several minutes.
10. With the suction tube on your siphon pump secured inside a bottle of new fluid, open the fill plug and pump a few ounces of fluid. This will help remove some of the residual gunk inside the case.
11. Replace the drain plug and pump the remainder of the 3 quarts into the case. When you approach 2.5 quarts, take it slowly until you reach the overflow threshold. This is the ideal amount for the transmission case.
12. In the event that you are close to using all three quarts and have not yet overflowed, bend a Q-tip 90 degrees and probe for fill level. As long as it is within roughly a centimeter of the overflow point, you should be okay. If not, add more fluid and repeat this test.
13. Replace the fill plug and belly pan, pick up your chock, and back off the ramps.

-Ash (ashman78)