Hi,

I will soon change m timing belt on my S40 2.0 (216'000km) and I'd like to change the camshaft front oil seal as a preventive maintenance (although I suspect them to start to leak). Following instructions in both Haynes manual and VADIS, I will need to remove the timing belt but also lock the camshaft not to ruin the timing...A warning states that attempting to do this job without locking the camshaft will irretrivieblably lead to the loss of the valve timing!

However I don't understand why I need to lock the camshaft especially because in VADIS/Haynes procedure, camshaft locking take place AFTER the removal of the camshaft pulley and the replacement of oil seals!

My thought was the following:

-Remove the timing belt
-Spray some paint around center of camshaft pulleys to mark the exact position of the retaining bolts.
-Remove the camshaft pulleys and change the oil seals
-Fit the camshaft pulleys in the exact position they were fitted before thanks to the marking of the bolts with respects to the pulleys
-Fit the new timing belt

Do you think this is a safe procedure or do I really need to lock the camshaft??? Why would I need to lock the camshaft?

(my car is a phase1 S40 2.0 normally aspirated)

Thanks