onestar

As some might have seen, I have the occasional 3rd gear slip and sometimes it gets confused on 4-3 gear or whatever gear. Im doing tranz fluid change in a couple days which isn't going to solve the issue, but sometimes you trick yourself into thinking it will. To keep it 100%, I'm a bit terrified dealing with this issue not only because it's my 1st Lexus (I just purchased), but due to it only having 109k miles. When I drove the car the other day I really focused on listening and feeling what's going on when the trans acts up.

To me it seemed like it's a computer software issue of the transmission that's causing these random shift issues. I did some digging only to find posts of master Lexus/Toya tech saying the 04-06 trans has a lot of issue's. The computer learning shift points, so an update came out that needs to be flashed. Calibration and then reset the computer memory for shift learned values. More times than not if caught early on it fixes the issue. Anyone here have success or experience with this issue? Or know the cost for the service or lack of maybe recall?

Oro

First, have you inspected all the motor/transmission mounts and the upper dog-bone mount?

Fixing these resolves a lot of transmission “jerkiness.” It really does.

The next thing I would do is add some Lubegard to the case (splash an ounce in the PS res, too, after you drain/fill it). The AW additives + ester oil to clean bores and condition seals will improve line pressure and shift precision. I spent years fighting issues like you describe. The transmission at 330k now shifts as well as it EVER has, and way better than 100k miles ago, with just very careful maintenance and some pro-active therapy for the solenoids and valve body (via the Lubegard).

Our car has never had a “flash” and it is great with the above steps. I have a friend with a much lower mile 2006, also not flashed but maintained, and it’s smooth and correct, too.

If you are swapping out the fluid soon, add some SeaFoam or Chemtool B12 for a few days of driving before you flush it. It will give a jumpstart on cleaning the valve bodies and solenoids. And check the three lower mounts and the upper strut. Use the correct fluid - T-IV or 3309 (same thing). Thinner fluid like WS, MaxLife, etc will alter shift points and lock-up time.