The fan is more then just a viscous. It is electrically controlled, I have seen both failures of the fan causing it to lock up and be loud, and there is a software fix for this as well, if it has stored a fault code.

 

Well I finally got up with the dealer in IL where this LR3 came from and they said they sent it to auction because it needed a new engine. Glad I called, I was about to pay for a pre-inspeciton. so I saved $150 with a 5 min call.

 

Going to look at an 05 HSE with only 44K on it. At this low mileage, when can I expect the rear diff to go?

service records show:
Coolant tank replaced
air compressor replaced
fuel tank replaced
new rotors/brakes last month

 

Don't expect it to go at all.

Change the fluid when you get it, and you should be fine. It is not a wear item, but they have had issues, more so with the front then the rear.

The main issues with the rear diff was with the locking ones, and that wasn't a mechanical issues, but with the electronics involved.

If it is locking, be sure to either use a LSD additive, or a gear oil that has an additive in it already.

 

I thought I would add my two cents worth to the life of the diff once the noise starts. Mine was already making a very slight noise when I got it, but it really was very slight. I have since done around 14K withthe last 4K being a drive from SK to NS with a trailer last week and now when you lift of the gas its getting to the point I really don't like it and can feel the vibration through the truck and the whine is now a heavy groooooan. I also have a second less obvious noise that its there all the time that sounds like two metal plates rubbing - its very slight, but getting worse, so maybe a bearing is also starting to give out. The truck is going to the shop for an inspection this week to confirm the problem is the diff, but having changed the diff oil 3 times in the last 14K and each time its pretty grotty all things point to the front diff. So to answer the original post - I have managed about 14K of normal driving - very little off roading.