I appear to have a significant leak from the front of the diff, on the seal around the input shaft. The petrol tank and the chassis tubes are coated in oil, and if I leave the car untouched for a week, an oil patch 5" wide collects on the garage floor. Should I be worried? There is still plenty of oil in the axle. The car has 18,000 miles on it
What is involved in replacing the seal, i.e. can an amateur do it, or does it involve the use of specialist tools?