Replaced my wife's '99 300 with an 05 330. back at the end of last year. The difference is amazing and makes the original 300 look like an old VW or something. The new one is a true Lexus in terms of look, fit and overall quality. EXCEPT for one thing- the transmission and it really ticks me off. We all know of the transmission issues of the 300's. We had ours replaced (under warranty) at about 50,000 miles.

Low and behold the transmission in the 330 is really worse than that in the old 300 drive wise. Don't know about longevity yet but it does not perform anywhere near the level I expect out of a Lexus. Around town driving conservatively it shifts well. The two biggest annoyances are when using cruse control on the highway it shifts in and out of overdrive at the slightest incline. Sometimes it shifts out of overdrive and down another gear or something because the RPM's shoot up and the engine howls. This ain't good for something. The other major complaint is sometimes when driving around town you will go to accelerate at about the time the transmission is up shifting and it clunks and gives a pretty good jerk. This can't be good either.

I have seen the issue with hesitation discussed here but not the two issues outlined above. Anyone else experience these symptoms? Am also curious if the latest software upgrade will address the problem or make it worse or create new ones. Does anyone specifically know what is addressed in the latest upgrade?

 

The 330 has 5-speed auto tranny with a fairly tall last gear to save gas, so it downshifts at the slightest incline. The 300 has a 4-speed tranny. It can handle up to 7% Interstate grade in 4th gear. I find it quite a joy to drive on highway with cruise.

Do you use premium gas? I've noticed that downgrading to regular makes the tranny shift a lot smoother in my RX300. Not sure if that can work for RX330. (I've gone back up to mid-grade for performance reason. VVT-i doesn't seem to kick in with regular gas.)

 

I have an 04 RX330 with the latest transmission software upgrade (I believe it's Feb 2006) I just got done in June and upshift and downshift smoothness has improved from the stock program (my RX was built Feb 2003 in Japan), especially from a rolling start (<15km/hr) when it used to downshift abruptly to first. However, it's still not "perfect"...

I noticed the downshifting/upshifting on inclines with the Cruise on but nothing out of the ordinary that any other car wouldn't do to maintain the set speed. I'll usually cancel the setting when I will approach an incline - I just don't like the idea of the car downshifting and wasting more gas to maintain the desired speed - I can live with a slight deceleration while maintaining (manual foot control) the same fuel input.

Now with the harsh upshift. I have the exact issue and it is reproducible most of the time under the conditions you described: when the tranny is about to upshift say from 2nd to 3rd under light to normal acceleration (say 2400 rpm) and you suddenly give more gas (half throttle) for whatever reason. It's as though the computer and/or mechanical components (i.e. clutch plate) cannot react quickly enough to the "new" fuel quantity and the result is first an additional 1 sec hesitation, then what appears to feel like the original intended upshift, followed by the actual harsh/clunky upshift.

Disappointing. Knowing this, I try to anticipate my driving a little more than normal to avoid the harsh upshift. Overall, not ecstatic, I am satisfied with the improvement of the reprogramming (it was pretty bad before).

To note: I drove the 2007 RX350 as a loaner for two days and the tranny was fantastic. Not only was it quicker to respond, not once did it shift harshly or appeared to be "confused" while I explictly tested it under many situations (rolling start, full throttle, half throttle, part throttle, deceleration then quick throttle input, ssudden increased throttle input prior to an anticipated upshift, etc.)

Cheers