Transaxle Installation – 2.5L NA

Overview

This guide details the procedure for installing the transaxle on all Porsche 944 variants with an 8-valve engine, covering both pre-1985.5 and 1985.5 onwards models. The transaxle, combining the transmission and differential, is reinstalled after maintenance tasks such as clutch replacement or transmission repairs. This process involves raising the transaxle, reconnecting the drive shaft, shift linkage, CV joints, and supporting components, with specific torque settings to ensure secure assembly. Model-specific steps are clearly marked for clarity.

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Tools Required

• Metric wrench set
• Metric socket set
• Jack stands
• Floor jack
• 8mm (5/16 inch) Allen head socket
• 8mm (5/16 inch) cheesehead tool
• Torque wrench
• Small flat tip screwdriver

Parts Required

• Loctite (for shift rod retaining bolt) – 944 423 010 00
• Steel lock wire (for shift rod retaining bolt) – 900 074 013 02

Step-by-Step Procedure

Step 1: Position the Transaxle

1. Raise the vehicle and secure it on jack stands to provide safe access to the underside.
2. Using a floor jack, carefully raise the transaxle into position against the torque tube bellhousing, aligning it properly.

Step 2: Install the Shift Linkage Rod

3. Insert the shift linkage rod protective tube into the transaxle case, ensuring the retainer is fully engaged.
4. Guide the shift linkage rod back until it engages the transaxle intermediate shaft.
5. Apply Loctite (944 423 010 00) to the shift rod retaining bolt. Install the bolt and torque to 21 Nm (15 ft-lbs) using a torque wrench.
6. Secure the bolt with steel lock wire (900 074 013 02) to prevent loosening.

Step 3: Connect the Drive Shaft

7. Through the access opening in the bottom of the transaxle case, slide the clamping collar into place over the drive shaft splines, aligning with the marks made during removal.
8. Using an 8mm (5/16 inch) Allen head socket, torque the clamping collar retaining bolts to 80 Nm (58 ft-lbs).

Step 4: Install Bellhousing Covers

9. Reinstall the transaxle bellhousing covers to protect the internal components.

Step 5: Install the Transaxle Support Cross-Member

10. Install the two M10 bolts to attach the transaxle support cross-member to the chassis using a metric socket set.
11. Torque the cross-member bolts to 46 Nm (34 ft-lbs) using a torque wrench.
12. Reattach the fuel filter to the cross-member.

Step 6: Secure the Transaxle to the Torque Tube

13. Install the four nuts and bolts (M12 and M10) to attach the transaxle case to the torque tube bellhousing using a metric socket set.
14. Torque the M12 fasteners to 85 Nm (62 ft-lbs) and the M10 fasteners to 42 Nm (30 ft-lbs) using a torque wrench.

Step 7: Reconnect Electrical Connections

15. For 85.5 Onwards models:

    • Plug in the speedometer sensor cable at the transaxle, if equipped with an electronic speedometer.

16. Connect the backup light wires near the top of the transaxle.

Step 8: Reconnect CV Joints

17. Reconnect the CV joints to the transaxle using an 8mm (5/16 inch) cheesehead tool.
18. Torque the CV joint bolts to 41 Nm (30 ft-lbs) using a torque wrench.

Step 9: Reconnect the Shift Linkage at the Shifter

19. For Pre-85.5 models:

    • Reattach the shift linkage to the shifter and secure it with the clip using a small flat tip screwdriver.

    • Reinstall the shift knob and secure it with the clip using a small flat tip screwdriver.

    • Reattach the rubber shift boot to the shifter opening.

    • Reinstall the trim piece at the base of the rubber boot, ensuring the clips are secure.

    • Reposition the carpet around the rubber boot.

    • Reattach the leather shift lever boot to the rubber inner boot.

20. For 85.5 Onwards models:

    • Reattach the shift linkage rod to the shift lever and secure it with the clip using a small flat tip screwdriver.

    • Reinstall the shift knob and secure it with the clip using a small flat tip screwdriver.

    • Reattach the rubber inner boot to the shifter opening.

    • Reinstall the shifter boot and inner trim ring to the console, ensuring a secure fit.

Step 10: Finalize Installation

21. Reconnect the negative battery lead.
22. Lower the vehicle from the jack stands.

Post Procedure Checklist

• Verify all bolts are torqued to the specified values (e.g., 21 Nm for shift rod bolt, 80 Nm for clamping collar).
• Ensure the shift linkage operates smoothly and engages all gears correctly.
• Check that the CV joints and drive shaft are securely connected with no play.
• Confirm all electrical connections (backup lights, speedometer sensor) are properly plugged in.
• Inspect for any leaks or loose components around the transaxle.
• Test drive the vehicle for 5 miles (8 km) to ensure proper transaxle operation.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manuals
• YouTube