How Long Do I Need To Service My Gearbox?

[Lex66b]

My is250 is 70000km now, when do I need to service the gearbox?

[BigDenis]

You don't. Lexus built the transmission to be service-free, and is sealed. It will supposedly last the life-time of the car. If you dropped the pan to change the transmission fluid, you would only be replacing 15 to 20 of the transmission fluid.

[E910]

If you look at the service schedule it recommends changing the fluid (WS) every 90K. Yes you don't change all of it but it does help by replenishing additives in the oil that will have broken down over that time. The synthetic oil its self technically doesn't break down, just the additive pack.