2. Install the spring support washers.
3. Press new oil seals onto the guide bushings using a mandrel or device (photo). Rotation of the seals during pressing is not allowed.
10.3 Pressing on caps using a tool
4. Lubricate the valve stem with engine oil and install the first valve. Install the valve retainer and crackers and check the spring height in working condition (i.e. the distance between the support washer and the lower surface of the plate in the closed valve position, photo). If necessary, adjust the height by installing additional support washers.
10.4 Checking the spring height in working condition
5. Remove the plate and crackers and install both springs with the tightly wound side down (photo).
10.5 Orientation of valve springs during assembly
6. Compress the springs and install the crackers. If necessary, lubricate the crackers with grease to temporarily secure them to the valve stem (photo).
10.6 Lubricate the valve stem retaining crackers
7. Install the remaining valves in the same way. Check the height of the springs again (photo) and adjust with support washers. It is not allowed to install extra support washers if the original height of the spring in working condition corresponds to the norm.
10.7 Rechecking the spring height
[Data taken from this portal: NissanBook.ru]
8. Install the camshaft, rocker shafts and tappets (on V6 engines).
9. On 4-cylinder engines, adjust the valve clearances to cold engine clearances.