WOW! This is a great thread. I have a 2000 NBS Silv 4x4 and bought it with 91k miles. At 100k miles I dropped the pan and changed the filter. I filled it up, ran it around the block a few times, and drained the fluid/filled it back up. (basically half of the fluid).
Would it be a good idea to drain the fluid every 15k miles (which would be half the fluid in the system)? I am under the belief that the fluid has "cleaning properties" and you dont want to do it too much, but figure I should change the fluid every 15k and fluid filter every 30k? Of course, I'm looking at preventative MX on my truck as I plan on keeping it a long time.
