Q: How do you replace a pinion seal and perform related tasks on a Nissan Pathfinder's differential assembly?A: Loosen the wheel lug nuts, raise and support the vehicle on jackstands, and block opposite wheels. Remove the wheels and disconnect the driveshaft. Rotate the pinion, check the torque, and mark the relationship. Count the threads, use the flange holding tool and remove the pinion nut. discard old seal, lubricate new seal, tap into position, install pinion flange, apply RTV sealant, install pinion nut, tighten the nut, measure torque, reinstall components, and reconnect driveshaft.