Camshaft Assembly Oil Seal Replacement

Tools

• Jack stands and floor jack
• Metric socket set
• Metric wrench set
• Porsche Timing Belt Tension tool P9201
• Flywheel Lock P9206
• Balance Shaft Pin Spanner P9200 or equivalent (if removing balance shaft sprockets)
• Gear puller (if removing crankshaft gear)
• 1/8" hex key
• 10 mm cheesehead tool

Other Procedures Needed

• ENG-03: Flywheel Lock Installation
• ENG-05: Camshaft and Balance Shaft Belt Removal
• ENG-06: Camshaft and Balance Shaft Belt Installation
• ENG-10: Camshaft and Balance Shaft Belt Tension — Checking and Adjusting
• ENG-13: Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1
• IGN-01: Distributor Cap and Rotor Replacement
• AF-01: Air Filter Housing and Air Flow Sensor — Removal and Installation

Parts

Description	Model/Year	Part Number
Front Main Camshaft Seal	944 (1983–1985)*, 944S (1987–1988)	999 113 282 40 (30 × 47 mm)
Front Main Camshaft Seal	924S, 944, 944 Turbo (1985–1991)	999 113 349 40 (32 × 40 mm)
Rear Distributor Housing O-Ring	924S, 944/S/T (all)	999 701 602 40 (50 × 5 mm)
Rear Distributor Housing Seal (small)	924S, 944/S/T (all)	928 105 184 00
Spacer Mylar Seal	924S, 944/S/T (all)	944 105 321 00
Rear Cam Housing Cover Gasket	924S, 944/S/T (all)	928 105 189 02

*For engines up to: #43F 06994 (M/T) / #43F 21202 (A/T)

Replacing the Front Camshaft Housing Seals

Refer to the timing and balance shaft belt drawings for your model:

• 1982–1986 models with eccentric roller tensioners
• 1987 and later models with spring tensioners

1. Disconnect the battery negative lead.

2. Using AF-01, remove the air filter housing and air flow sensor.

3. Remove the alternator and power steering belts.

4. Remove the front timing covers.

5. Using IGN-01, remove the distributor cap and rotor.

6. Remove the front distributor housing cover.

7. On cars not equipped with spring tensioners (pre-1987): a. Loosen the camshaft tensioning roller locknut and turn the tensioning roller nut clockwise to release tension on the timing belt. Hold the flats on the tensioner roller with an open-end wrench while loosening the locknut to provide counter-torque — failure to do so stresses the tensioner stud and can cause long-term failure.

8. On cars equipped with spring tensioners (1987 and later): a. The front plate of the spring tensioner resembles a triangle. Loosen, but do not remove, the locknut and bolt on the side near the tensioning spring. b. Release tension by pushing down on the tensioner lever arm. With the spring compressed, tighten the locking bolt and nut to hold the tensioner in the released position.

9. With the timing belt detensioned, slide the belt off the camshaft sprocket.

10. The camshaft sprocket is held by a retaining collar (Figure 1, item 18). Remove the rotor and the front distributor housing, then remove the bolt (10 mm) that holds the ignition connector in the collar and pull the connector straight out. The connector may be difficult to remove and may require heating the outside of the recess to loosen.

11. Behind the connector, locate the M10 × 65 mm bolt in the retaining collar (Figure 1, item 19). This bolt holds the retaining collar and sprocket to the end of the camshaft.

12. Before attempting to remove the cheesehead bolt, "wake it up" by inserting the cheesehead tool into the bolt head and tapping the tool with a hammer several times.

Caution: DO NOT ALLOW THE CAMSHAFT SPROCKET TO TURN MORE THAN A FEW DEGREES while loosening the cheesehead bolt. Excessive rotation will cause the valves to contact the pistons and can cause serious engine damage.

Hold the flats on the camshaft sprocket retaining collar (1-1/4") with an open-end or combination wrench while turning the cheesehead bolt. A second person holding the wrench is strongly recommended. Cheesehead bolts strip easily — keep the tool fully inserted and straight throughout removal.

13. Once the cheesehead bolt is removed, slide the retaining collar and camshaft sprocket straight off the end of the camshaft. Do not rotate the sprocket or collar while removing — they are positioned by a woodruff key, so any rotation also turns the camshaft.

14. Remove the woodruff key from the slot in the camshaft. Diagonal cutters or needle-nose pliers work well for this.

15. Remove the three bolts holding the rear distributor housing to the camshaft housing.

16. Slide the rear distributor housing off the camshaft.

17. The spacer (Figure 1, item 20) will likely come out with the rear distributor housing, held by the main camshaft seal. If so, a thin mylar seal (Figure 1, item 23) will be visible on the end of the camshaft — replace this seal. If the spacer did not come out, slide it off the camshaft and replace the seal.

18. Replace the three seals on the rear distributor housing:

    • The main shaft seal (Figure 1, item 22) goes into the front of the housing.
    • A large O-ring (Figure 1, item 21) goes in the back of the housing.
    • A small round seal (Figure 1, item 13) also goes in the back of the housing, installed in the rear distributor housing cover (not the cam housing front as the exploded view may suggest). Apply a small amount of engine oil or bearing grease to all seals before and after installation.

19. Install the new seals on the distributor housing and slide the housing onto the end of the camshaft.

20. Install the three distributor housing retaining bolts (M6) and torque to 8 Nm (6 ft-lbs).

21. Insert the woodruff key into the slot in the camshaft and install the camshaft sprocket and retaining collar.

22. Install the M10 × 65 mm bolt into the retaining collar:

    • Cheesehead bolt: torque to 65–70 Nm (48–52 ft-lbs)
    • Hex head bolt: torque to 45 Nm (33 ft-lbs)

23. Install the connector into the recess in the retaining collar.

24. Apply Loctite to the connector retaining bolt (M5 × 10 mm), insert into the collar, and tighten.

25. Verify the crankshaft has remained at TDC (ENG-13).

26. Align the camshaft sprocket to TDC using the scribe mark on the sprocket and the alignment mark on the rear distributor housing.

27. Install the camshaft belt onto the camshaft sprocket, ensuring no slack on the portion running from the camshaft sprocket to the crankshaft gear.

28. Tension the camshaft belt using ENG-10.

29. Install the timing belt covers.

30. Install the alternator and power steering belts.

31. Install the air flow sensor and air filter housing (AF-01).

32. Reconnect the battery negative lead.

Rear Cam Housing Gasket Replacement

The rear cam housing gasket can be replaced without a full cam housing removal. Porsche used a cork gasket on the rear cam housing cover.

1. If equipped with a TDC sensor, an electrical connector is attached to the rear engine lifting ring. Remove the 10 mm bolt holding the connector retaining strap to the lifting ring and move the connector out of the way.
2. Remove the three M6 bolts holding the lifting ring and rear cover to the cam housing (10 mm socket or wrench).
3. Apply a thin coat of bearing grease to both sides of the new gasket (Figure 1, item 9).
4. Position the gasket onto the rear cam housing cover and install the cover and lifting ring using the three M6 × 22 mm retaining bolts.
5. Torque the retaining bolts to 8 Nm (6 ft-lbs).