Camshaft (Timing) Belt Installation

Overview

This procedure outlines the steps to install the camshaft (timing) belt on all Porsche 944 engine variants with an 8-valve engine. The timing belt synchronizes the crankshaft and camshaft, ensuring proper engine operation. Correct installation is critical to prevent engine damage. This guide covers the 1983–1985.5 (pre-85.5) and 1985.5–1988 (85.5 onwards) models, noting differences where applicable.

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Tools Required

• Jack stands
• Floor jack
• Metric socket set (including 13mm (1/2 inch), 17mm (11/16 inch))
• Metric wrench set (including 10mm (3/8 inch), 13mm (1/2 inch))
• Porsche Timing Belt Tension tool (P9201)

Parts Required

• Timing belt, 944 105 157 02
• Water pump idler roller (if replacing), 944 105 027 02
• Camshaft sprocket (if replacing), 944 105 053 00
• Crankshaft gear (if replacing), 944 102 277 04
• Timing belt tensioning roller (if replacing), 944 105 241 02 (Pre-85.5 with eccentric roller) or 944 105 321 00 (85.5 Onwards with spring tensioner)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1

Step-by-Step Procedure

Step 1: Prepare the Engine

1. Disconnect the battery to ensure safety during the procedure.
2. Raise the vehicle using a floor jack and secure it with jack stands.
3. Follow this link to ensure this step – Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1 – of the process is followed accurately to set the crankshaft to TDC for cylinder number 1.

Step 2: Install Timing Components

4. Install the rear timing cover if it was removed, ensuring it is securely fastened.
5. Install the water pump idler roller, 944 105 027 02, if removed. Tighten the retaining bolt to 45 Nm (33 ft-lbs) using a 13mm (1/2 inch) socket.
6. Install the crankshaft gear, 944 102 277 04, if removed. Ensure the lip on the timing gear faces toward the front of the car.
7. Install the camshaft sprocket, 944 105 053 00, if removed. Align the mark on the camshaft sprocket with the mark on the rear distributor housing.
8. Install the timing belt tensioning roller, 944 105 241 02 (Pre-85.5) or 944 105 321 00 (85.5 Onwards), if removed. For 85.5 Onwards models with spring tensioners, consider installing the tensioner during belt routing for easier installation.

Step 3: Install the Timing Belt

9. Place the timing belt, 944 105 157 02, onto the crankshaft gear.

For Pre-85.5 models:
Route the belt around the camshaft sprocket, ensuring no slack between the camshaft sprocket and crankshaft gear. Verify that neither the crankshaft nor camshaft sprocket moves from TDC.
Continue routing the belt around the water pump pulley and tensioning roller.

For 85.5 Onwards models:
If using a spring tensioner, install it now if not already installed. Route the belt around the camshaft sprocket, ensuring no slack between the camshaft sprocket and crankshaft gear. Verify that neither the crankshaft nor camshaft sprocket moves from TDC.
Continue routing the belt around the water pump pulley and spring tensioner.

10. Adjust the timing belt tension according to the Porsche 944 Workshop Manual, using the Porsche Timing Belt Tension tool (P9201) to ensure proper tension.

Step 4: Verify Alignment

11. Rotate the crankshaft two complete turns using a 17mm (11/16 inch) socket and set it back to TDC for cylinder number 1.
12. Verify that the camshaft sprocket mark aligns with the mark on the rear distributor housing, confirming TDC alignment.

Step 5: Finalize Installation

13. Install the front timing belt covers, securing them with the appropriate bolts using a 10mm (3/8 inch) wrench.
14. Reconnect the battery.

Post Procedure Checklist

• Check that the camshaft sprocket and crankshaft are aligned at TDC for cylinder number 1.
• Ensure the timing belt is properly tensioned with no slack.
• Verify that all bolts are torqued to the specified values (e.g., idler roller bolt to 45 Nm (33 ft-lbs)).
• Inspect for any loose components or tools left in the engine bay.
• Start the engine and listen for abnormal noises, indicating potential misalignment or improper tension.

Sources

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