Withdrawal
The engine temperature must be below 38°C. To facilitate installation, make sure the Number 1 piston is at Top Dead Center before removing the camshaft.
1. Remove valve cover.
2. Remove the distributor or camshaft position sensor from the end of the camshaft.
3. Remove the camshaft pulley fixing bolt and washer and remove the camshaft pulleys along with the Woodroof keys, if any.
4. Before removing the rocker arm set, measure the camshaft end play as follows:
Do not rotate the camshaft while checking. Loosen the rocker arm adjustment screws before starting.
- a. Install the camshaft by moving it towards the end where the distributor is located.
- b. Install a dial indicator on the end of the camshaft. Zero the dial indicator against the end of the distributor drive, then move the camshaft back and forth, determine the axial clearance; do this for both camshafts.
- c. The standard camshaft end play for a new camshaft is 0.05-0.15mm.
- d. The standard service limit for camshaft end play is 0.5 mm.
5. Loosen the bolts of the camshaft struts and rocker axles in a cross pattern, starting from the outer strut.
6. Remove rocker arms, axles and strut assemblies.
7. Remove camshafts.
8. Wipe the camshaft clean, then inspect the working parts of the cams. Replace the camshaft if the camshaft lobes are corroded, seized or excessively worn.
If the radial clearance of the camshaft bearings is out of tolerance and the camshaft has already been replaced, then the cylinder head must be replaced.
For installation:
9. After cleaning the surfaces of the camshaft and the necks of the shafts, lubricate both surfaces with aggregate grease and install the camshaft.
10. Rotate the camshaft until the keyway is facing up (cylinder number 1 at top dead center).
11. Set the rocker arms to their original position. Place the rocker arms on the pivot bolts and valve stems. Valve lock nuts must be loosened and adjusting screws removed prior to installation.
12. Install the camshafts and camshaft seals with the open side (spring) inside. When installing the camshaft struts, note that each is marked with a letter, a number and an arrow. The arrow points towards the front of the engine and each strut MUST be installed correctly, E1 first on the exhaust side and l6 last on the intake side.
13. Apply a liquid gasket to the surface of the cylinder head mating with the number 1 and number 6 camshaft struts, then install these struts together with the number 2, 3, 4 and 5 camshaft struts.
14. Be convinced that shoulders of yokes are correctly located on rods of valves and temporarily tighten racks of a camshaft.
Use a non-hardening material to seal the surface of the cylinder head on each side adjacent to the camshaft seals (ov).
15. Using an oil seal installer of the correct diameter and length, install new camshaft oil seals.
16. Tighten each rocker bolt in two-turn increments in the appropriate sequence, working from the center and spiraling outward. Take care that the rocker arms do not pinch the valves.
17. Install the keys in the grooves of the camshaft. Slide the camshaft pulleys onto the camshaft, then install a new washer with fixing bolt.
To install the number 1 cylinder at top dead center, align the hole on the camshaft with the hole in the number one camshaft rack and insert a 5mm pin into the holes.
18. Install the distributor or camshaft position sensor.
19. Adjust valves.
20. Install the valve cover.
Inspection
The camshaft must be handled with care; it will be damaged if dropped or subjected to a sharp blow.
Remove grease from the camshaft using a safe solvent. Clean all oil grooves and passages. Inspect the cams and camshaft journals for wear. If in doubt, check all cams and necks with a micrometer. A worn camshaft will result in short service intervals or frequent oil and filter changes.
Measure the cam lobe from nose to base and again at a 90°angle. Lift is determined by subtracting the second measurement from the first. If all exhaust lobes and all intake lobes have different heights (compare intake cams with intake cams, and exhaust cams with exhaust cams), the camshaft must be replaced. Measure the camshaft journals and compare with the table in this Chapter. If the journal is worn, the camshaft must be replaced.
If the cams and journals appear intact, place the front and rear camshaft bearing journals in V-blocks and attach a dial indicator to the center journal. Rotate the camshaft to check its straightness, if the deviation exceeds 0.025mm, replace the camshaft.