Valve Springs
Valve Springs
Removal
All valve springs
1. Depending on the valve being serviced, remove the LH or RH valve cover. For additional information, refer to Valve Cover - LH Valve Cover - LH or Valve Cover - RH Valve Cover - RH.
2. Remove the spark plug. For additional information, refer to Engine Ignition - 6.8L (3V) Spark Plugs.
3. Rotate the crankshaft until the piston for the valve being serviced is at the top of its stroke with the intake valve and the exhaust valves closed.
Cylinder No. 7 front intake valve spring
4. NOTICE: The balance shaft bearing caps must be installed in their original locations or engine damage may occur. Record camshaft bearing cap locations.
Using the sequence shown, remove the 6 bolts, then the 3 balance shaft bearing caps and the balance shaft.
5. Remove the 2 bolts and the camshaft bearing cap.
Cylinder No. 10 front intake valve spring
6. NOTICE: The balance shaft bearing caps must be installed in their original locations or engine damage may occur. Record camshaft bearing cap locations.
Using the sequence shown, remove the 6 bolts, then the 3 balance shaft bearing caps and the balance shaft.
7. Remove the 2 bolts and the camshaft bearing cap.
All valve springs
8. NOTICE: If the components are to be reinstalled, they must be installed in their original locations or engine damage may occur. Mark the components for installation into their original locations.
NOTE: Do not allow the valve keepers to fall off the valve or the valve may drop into the cylinder. If a valve drops into the cylinder, the cylinder head must be removed. For additional information, refer to Cylinder Head Cylinder Head - Removal.
NOTE: It may be necessary to push the valve down while compressing the spring.
Using the Valve Spring Compressor, compress the valve spring and remove the camshaft roller follower.
9. Use compressed air in the cylinder to hold both valves in position.
- Apply a minimum of 965 kPa (140 psi) of compressed air into the cylinder.
10. NOTICE: If air pressure has forced the piston to the bottom of the cylinder, any loss of air pressure will allow the valve to fall into the cylinder. If air pressure must be removed, support the valve prior to removal.
NOTICE: If the components are to be reinstalled, they must be installed in the same positions or engine damage may occur. Mark the components for installation into their original locations.
NOTE: If a valve drops into the cylinder, remove the cylinder head. For additional information, refer to Cylinder Head Cylinder Head - Removal.
Using the Valve Spring Compressor, compress the valve spring and remove the valve spring retainer keys.
11. Remove the valve spring retainer and the valve spring.
12. Inspect the valve spring. For additional information, refer to Engine System - General Information Valve.
Installation
All valve springs
1. NOTICE: If the components are to be reinstalled, they must be installed in their original locations or engine damage may occur.
Using the Valve Spring Compressor, install the valve spring, the valve spring retainer and the valve spring retainer keys.
2. Relieve the air pressure from the cylinder.
3. NOTICE: If the components are to be reinstalled, they must be installed in their original locations or engine damage may occur.
NOTE: Do not allow the valve keepers to fall off the valve or the valve may drop into the cylinder. If a valve drops into the cylinder, the cylinder head must be removed. For additional information, refer to Cylinder Head Cylinder Head - Removal.
NOTE: It may be necessary to push the valve down while compressing the spring.
NOTE: Lubricate the camshaft roller followers with clean engine oil prior to installation.
Using the Valve Spring Compressor, compress the valve spring and install the camshaft roller follower.
Cylinder No. 7 front intake valve spring
4. Position the camshaft bearing cap and install the 2 bolts.
- Tighten to 10 Nm (89 lb-in).
5. Lubricate the balance shaft journals with clean engine oil.
6. NOTE: Camshaft sprocket removed from art for clarity.
NOTE: It may be necessary to rotate the crankshaft to align the balance shaft timing marks.
Position the balance shaft on the journals and align the timing mark on the balance shaft with the camshaft timing mark as shown.
7. NOTICE: The balance shaft bearing caps must be installed into their original locations or engine damage may occur.
Position the 3 balance shaft bearing caps and install the 6 bolts and tighten in the sequence shown.
- Tighten to 10 Nm (89 lb-in).
Cylinder No. 10 front intake valve spring
8. Position the camshaft bearing cap and install the 2 bolts.
- Tighten to 10 Nm (89 lb-in).
9. Lubricate the balance shaft journals with clean engine oil.
10. NOTE: Camshaft sprocket removed from art for clarity.
NOTE: It may be necessary to rotate the crankshaft to align the balance shaft timing marks.
Position the balance shaft on the journals and align the timing mark on the balance shaft with the camshaft timing mark as shown.
11. NOTICE: The balance shaft bearing caps must be installed into their original locations or engine damage may occur.
Position the 3 balance shaft bearing caps and install the 6 bolts and tighten in the sequence shown.
- Tighten to 10 Nm (89 lb-in).
All valve springs
12. Install the spark plug. For additional information, refer to Engine Ignition - 6.8L (3V) Spark Plugs.
13. Depending on the valve being serviced, install the LH or RH valve cover. For additional information, refer to Valve Cover - LH Valve Cover - LH or Valve Cover - RH Valve Cover - RH.