@Drover its a bit of a drama installing a cooler but once done you won't regret it.
Even changing the trans oil at 30,000 the first was was a bit of a worry like you said a lot of sludge, the trans change after that was clean and had hardly any sludge at all on the last oil/filter change.
Mind you, I over change all our filters on the Colorado way before they are due.
- Fuel filter every 10,000 is a lot cheaper than a new injector/pump/motor.
- Trans every 30,000 only using Delco trans fluid (Dex 6).
- Oil filter and oil every 5,000 5/30 and wanting to upgrade on the next one to 10/40 due to traveling up north at temps 35+
- Air filter as required
- Diffs (Penrite) and transfer case (Delco Dex 6) every 30,000 the transfer oil is usually dirtier than the trans oil I find. Our rear diff oil is alway dirty as well, keeping a eye on that one.
@The escapist I would be advising changing that oil asap and even get a trans oil cooler as well wouldn't hurt.
Planning on a big lap next year but I think I will extend the oil changes to 10,000. I will wait until arriving back in WA for the rest so I can use a hoist, its too hard on the ground as you hinted Drover.
I have 2 other mates with the same 2013 and all of us have over serviced our RG and all have had no major break down so far. One has just clicked 200 thousand and he tows a mini digger (excavator) behind and he is just about to up grade to the new RG. He doesn't want to part with the old faithful because it's been a reliable car but the accountant insists on him upgrading due to tax reasons. We all find they are reliable but it's all due to the servicing I would say