Valve Train Servicing Precautions
CAUTION:
Wait recommended time to permit hydraulic cam followers to compress. If wait time is not followed, valves appear to be closed but may actually be open and come in contact with pistons. Failure to wait recommended time may damage engine.
NOTE:
Hydraulic cam followers expand when camshaft is removed and require a certain amount of time after installation before they compress.
- If camshafts will be removed and installed without removing cylinder head from engine, turn crankshaft in normal direction of rotation about 30 degrees from TDC. This will keep valves from hitting pistons.
- Install camshafts with lobes for cylinder No. 1 facing each other. Use Camshaft Locating Fixture (11-3-240) to align and hold camshafts. See Fig 1 or Figure.NOTE: Always wait specified time between installation of camshaft and installation of cylinder head. See CYLINDER HEAD INSTALLATION WAITING TIMES table.CYLINDER HEAD INSTALLATION WAITING TIMES
Temperature °F (°C) Minutes 68 (20) 4 50-68 (10-20) 11 32-50 (0-10) 30 - Wait recommended time to permit hydraulic cam followers to compress. See CYLINDER HEAD INSTALLATION WAITING TIMES table. Turn crankshaft back to TDC position.
- Use TDC Aligning Plug (11-2-300) to hold crankshaft in TDC position. Install timing chain. Remove camshaft and crankshaft holders. Wait at least 10 minutes before cranking engine. See ENGINE CRANKING WAITING TIMES table.
NOTE:
Engine may be cranked only after waiting specified time after installation of camshaft and timing chain. See ENGINE CRANKING WAITING TIMES table.
ENGINE CRANKING WAITING TIMES
| Temperature °F (°C) | Minutes |
|---|---|
| 68 (20) | 10 |
| 50-68 (10-20) | 30 |
| 32-50 (0-10) | 75 |