Scotty,
I watched your recent video about how to change the transmission fluid in a car with a sealed transmission with great interest. You said that if you DYI this job, you won't get all the fluid out but that it would be good enough. And you said to do it every 60,000 miles.
I bought a 2008 Lexus GS-350 AWD a few years ago. It had 65,000 miles on it. After listening to your earlier videos, I decided to have the transmission fluid completely changed. I also had them change the transmission filter. While they were at it, I had them service both differentials. I knew I would have to have a professional do it and I knew this would be an expensive job. I plan to do this every 60,000 miles. After that, I had them do the same service on my wife's 2004 Honda CRV (which fortunately does not have a sealed transmission).
I am a big believer in preventative maintenance. But am I taking things too far?
Hugh
A bit. You don't need to do diffs at 60k unless you're towing/hauling.