Manual Transaxle Fluid Change

Fluid Specification

The factory-specified fluid for the 924/944/968 manual transaxle is:

• Hypoid gear oil SAE 75W-90 to API GL-5 or MIL-L 2105B
• Alternatively: SAE 80 to API GL or MIL-L 2105

Commonly used alternatives that meet or exceed these specifications include Redline Synthetic MTL, Swepco 201, and Mobil 1 75W/90. Motul Gear 300 and Royal Purple Synchromax are also widely used in the 924/944/968 community.

Note: There has been discussion in the Porsche community about whether certain synthetic gear oils may accelerate wear on bronze synchronizer rings. This concern has been raised specifically regarding Mobil 1 75W/90, but it has never been substantiated with documented evidence. Many owners run Mobil 1 and similar synthetics without issue.

Capacity: approximately 2.75 quarts / 2.6 liters

Tools

• 17 mm Allen head socket
• Oil drain pan
• Fluid pump or filler tube long enough to reach the fill hole from above the wheel well

Procedure

Caution: Remove the fill plug before draining. If you drain the transaxle first and then find that the fill plug is seized, the transaxle will be empty with no way to refill it. Confirm the fill plug breaks loose before committing to the drain.

1. Warm the transaxle by driving the car a short distance. Warm fluid drains more completely than cold fluid.

2. Raise and support the car on jack stands.

3. Locate the drain and fill plugs on the left side of the transaxle. The upper plug is the fill plug; the lower plug is the drain plug. Both use a 17 mm Allen head socket.

4. Remove the fill plug (upper) first. Confirm it is fully removed before proceeding.

5. Position a drain pan under the lower plug and remove the drain plug. Allow the fluid to drain completely.

6. Clean the drain plug threads and reinstall the drain plug. Torque to 24 Nm / 18 ft-lbs.

7. Warm the new fluid before filling. Placing the container in front of a heat lamp for approximately 20 minutes reduces viscosity and makes it easier to pump into the transaxle.

   Caution: Do not warm gear oil in a microwave oven.

8. Route the filler hose up and over the top of the left rear wheel well and around or above the exhaust to reach the fill hole from a convenient angle. Fill the transaxle until fluid just begins to run out of the fill hole.

   Tip: Filling to the bottom edge of the fill hole is the standard method. The transaxle is full when fluid begins to drip from the hole with the car level.

9. Reinstall the fill plug and torque to 24 Nm / 18 ft-lbs.

10. Lower the car. Check both plugs for leaks after the first drive.