First off, great choice of vehicle, I love my Y61 (possibly a little too much according to my friends/family :augie :lol). Great trucks, very capable, and that mileage, although a little high, shouldn't be a problem if it's been maintained (like most vehicles).
Bad rust on the chassis or body is really the main one to look out for as with any 4x4 of that age/mileage. Make sure to check around the inside of the rear wheel arches as the plastic trim creates a lip which can become a bit of a mud trap :thumb2
At that age you should be out of the woods with regard to the issues with the early 3.0 engines as by the time they made the one you're going to see they had prety much sorted the problems and started fitting them in the Terranos. Might want to ask if there's been any engine issues anyway though.
Leaky ball joints are just one of a number of wear related issues that aren't particularly Trol specific. If it does have leaky ball joints it's not the end of the world as the 4wd is part time (so lack of axle oil won't cause diff wear during normal driving) but factor in the cost of a whole hub rebuild kit (or parts thereof) as chances are the swivel bearings have had it and it's the play in the swivel that's causing the inner axle seal to leak. Also for your own sanity you're gonna want to factor in garage costs for getting the work done as on the Y61's it's a bugger to seat the inner axle seal correctly - when I needed to get my offside one done I got a local garage to do it as I'd heard from the Aussie forums that it was a PITA. Just as well as the garage had take the swivel apart 3 times before they got it the axle to seal :doh (they didn't charge me extra for that!).
I would say the main wear related issue for a Y61 at that age and mileage is that the flywheel might want replacing as the DMF fitted as standard is the weak point in the driveline - the 3.0 engine can produce more power than the flywheel is designed for and as the rest of the dirveline is particularly beefy (its the same as fitted to the 4.2 Y61s) the DMF will often fail prematurely. Symptoms are a rattle on hot startup which gets progressively worse. This is an expensive repair but you can get a solid flywheel and clutch kit to prevent it happening again. I ordered mine from a company in Aus with an HD clutch and got a local garage to fit it. Doing it that way cost me the same for parts (inc delivery) and labour as I would have paid to get the kit on it's own in the UK
Don't worry if the oil pressure warning light has a habit of staying on as it's more likely than not that it's just the high oil pressure switch starting to fail. The 3.0 has two pressure switches, high and low. Low is very easy to get to and very unlikely to fail. High is very hard to get to and very likely to fail
To replace the high oil pressure switch you either need contortionist skills and a lot of patience or have to take the engine out, although it will fail again as it can't cope with the pressure fluctuations. I decided not to bother replacing mine and instead I fitted an oil pressure gauge so I can monitor the pressure manually (much better than an on/off warning light anyway).
That's all that comes to mind at the moment anyway...
