I purchased a 2008 Toyota Kluger via a dealer in November 2016. This car has a 5 year warranty and underwent a 90 000km service with Toyota while under statutory warranty. The transfer output oil leak was diagnosed by Toyota at this service. The car was sent to an warranty authorised mechanic who repaired the car under statutory warranty. However, despite having visited the mechanic 6 times, the leak persists and the stat. warranty has since expired. The mechanic now claims, that their original diagnosis (and Toyota's) was incorrect, and that the leak is not coming from the transfer output seal (which they have replaced twice) but another part of the car. If I recall correctly, they believe the leak is caused by a 'breather box' problem. I gather there is a circular plate in this box, which has a small pin hole sized hole in it. According to the mechanic, this plate has a manufacturing fault and have suggested they use a sealant to repair the problem, or, they can replace the entire shaft which will provide "...no guarantee the leak wont still occur, as parts are made in runs....". AutoCo's suggestion is to have the plate sealed rather than have the shaft replaced. I'd like your opinions on the following:1) Do you believe the sealant repair option is going to be the best option? The mechanic does not want to replace the faulty part at $3 000 per shaft, and I am not confident that a sealant repair will be a permanent solution to this leak!2) Should I be asking the dealer to replace this car?In my view, this car had a pre-existing fault at purchase, and I have met my obligations to ensure that the car was in good mechanical condition, having had it serviced while still under statutory warranty. I would like the dealer to replace the car with a similar vehicle, but before I make this request I wanted to check in with the Toyota massive for some alternative opinions. Tired and frustrated!!