New flywheel bolts must be used on refitting. To remove the flywheel, first take out the manual transmission and the clutch assembly. Prevent the flywheel from turning by locking the ring gear teeth with a special tool or by using a long bolt in one of the engine-to-gearbox mounting bolt holes while inserting a wide-bladed screwdriver into the starter ring gear. Unscrew the securing bolts and withdraw the flywheel from the crankshaft, noting that the flywheel bolt holes are offset for proper alignment. Discard the old bolts as new ones are required for refitting. For inspection, if the flywheel's clutch mating surface is deeply scored, cracked, or damaged, it must be renewed, and advice from a Nissan dealer or engine reconditioning specialist should be sought. If the ring gear is badly worn or has missing teeth, it also needs to be renewed, and checking with a Nissan dealer or engine reconditioning specialist is recommended to determine if the flywheel can be repaired. For refitting, locate the flywheel on the crankshaft, insert the new securing bolts, and tighten them in a diagonal sequence to the specified torque while holding the flywheel stationary as during removal. Do not oil the new bolt threads as they come with a locking compound. Finally, refit the clutch and remove the locking tool if used, then reattach the transmission.