Well I changed my tcase fluid this weekend and was it a mess. It looked more like gear oil than ATF. My titan has 22k and I sure didn't expect it to look this bad. There was at least .5 of an inch of crud stuck to the plug. I flushed it out with atf and then added mobil 1 atf. Funny thing is the trans fluid looks like new compared to the tcase fluid.

The trans fluid is a different type of fluid and yes it certainly does hold up well. I changed the transmission fluid on my last truck at 20k miles and it looked every bit as good as the new stuff I put in it. Hopefully this is a good sign that the trannies are easy on the oil and will last many many years.

I changed my xfer case fluid to M1 ATF, too. Mine wasn't terrible, though, as I only had about 5,400 on it.

On the tranny fluid......my dealer told me that they were changing the fluid now based only on fluid analysis, instead of changing at recommended interval. This kinda makes sense, since this is the best indicator of the condition of the fluid. We do the same thing on large chillers and a/c systems at work.