Replace components that are worn more than the maximum limits.

Do an inspection for damage caused by corrosion.

Measure the volume of the oil carefully.

Make sure that the nuts are tight.

There are three jacking points on the fuselage.

Make sure that the tension in the cables is correct.

Operate the engine at 100% thrust.

Slowly turn the vane.

Apply sealant on the outer surface.

Find the damaged areas.

Make sure that the pipe is not clogged.