One problem related to transfer case has been reported for the 2000 Lexus RX300. The most recently reported issues are listed below.
After a few weeks of feeling occasional slippage in the drive train of my 2000 Rx300 (118k miles), I had my local mechanic check it out. He drove tested it, checked all fluid levels, visually inspected the transmission, transfer case, u-joints etc and couldn't find a problem. Today with no further notice, the transmission fully broke - lurching, clunking, and after pulling over total slippage. I had it towed to a transmission shop where I'm waiting for an evaluation of the situation. If this had happened on a busy highway, I could have caused a severe accident, as there was no acceleration causing a very unsafe and dangerous situation.