I have searched and searched and asked around but could not get a satisfying answer.

I have a 2008 ISF at 41k miles.
In stop and go traffic, or starting from a stop and driving causally ( not WOT or even medium throttle) the car will rev up before going into 2nd. It is like the feeling of rolling over a speed bump.

Also in normal or sport mode in D ( not M ) if I WOT , you can feel it jerk before taking off. I dont know if this is normal or not

08 w/94k. Only odd shift I feel is driving around in parking lot sometimes it feels like it can't decide if it wants 1st or 2nd gear. Revs a bit before settling on gear. This is under very light acceleration and has only happended 3 or so times.

This happens to me at every single stop and go under little acceleration, it literally feels like small ''lunge in the seat'' before going to the next gear.

My 2011 does the same, nothing to worry about. I'm no tech by any means but I think it has to do with the torque converter locking up fully after 2nd gear. That is why such a difference in first to second gear.

From what I've read you might want to get your transmission fluid level checked.. The isf is known to have "cold flair" where the gear feels like it's slipping from 1st -> 2nd or 2nd -> 3rd right after starting the car up.. But if it's happening consistently I personally would have the levels checked just to ease your mind. It you search cold flair or transmission slip on here there are a couple great threads with some expert input (lobuxracer and others) dealing with the topic.

The transmission locks the converter in M/sport mode. If you're experiencing rough or unusual shifting in D mode, you should have your transmission fluid level checked.

Try transmission oil flush and change at Lexus dealer and see.

There is no procedure in the service manual to do this, and I've had my ATF tested by Blackstone twice now. It's still good at 120k miles. It's a waste of everything to attempt to change it before it is time. The only thing you need to do is ensure the level is set correctly and you'll be fine.

The flare issues disappear when the level is set right.

Sorry to steal thread was wondering when u should change the trans fluid ?

How do you ensure it is set properly at the correct level?

I wouldn't mess with transmission oil unless you have check engine light or running rough, slipping. I change my 3 time 2 quart each and my car seem to run better.

To flush and change all transmission only Lexus dealer had machine to do it and they charge $250.

And again, there is no procedure in the factory service manual to do this. Lexus specifically says never required, and I have used oil analysis supporting their claim to 120k miles. The only thing necessary is to properly adjust the level. The adjustment procedure is in every one of these threads that keep popping up every 6 months or so.

Nothing last forever.

Including the friction materials in the transmission regardless of whether you choose to change the fluid or not.