at 110k it needs the new fluid and a clean filter, even if that is not what's causing the current problem. doing the fluid will at least rule out that potential cause.

 

Did you know that Lexus recommends changing the transmission fluid at 100k miles. I know this sounds crazy but this is the factory recommended interval. It seems to me, that you run a greater risk by introducing too much new fluid at once. This may cause sludge to Loosen in large and damage the transmission. The recommended procedure is to introduce only 2 courts at a time that way it will not dislodge any sludge in large amounts. I don't believe that dropping the pan will hurt anything but I think that you are wasting your money. Given, that it is only a screen in there and not a filter. Don't forget to buy a new drain bolt and washer if you remove them.