Can you please elaborate, rbock? I only have 56k miles on our 06 and did a tranny service two months ago. It did seem to shift smoother and seamlessly immediate after the "drain and fill" but has returned back to perceptible shifts.

 

I changed all 12 qt. out like in the mother of transmission thread. It wasn't that bad to do. If you are just draining out the pan, you are just getting 3 or 4 qt. of new fluid.

 

This is close to the procedure for some Toyota Aisin 6 speed transmissions.



It's pretty involved, and usually this type of work is relegated to the teenage lube jockey making 12 bucks an hour. I'm sure there are shortcuts you can take.



YMMV, but these steps are there for a reason.

 

yeah i have to say, i prefer the 5 sp to the 6 sp. It seems the 5 sp in my '01 was always tight and crisp, whereas the 6 sp in my '05 every so often hunts for the gear and doesn't go into 6th gear with the crispness i'd expect. I don't think there is anything wrong with it, that's just the way it is. Improvement in gas mileage with the 6 sp? i doubt it. I guess maybe it would have a quicker takeoff with a lower first, but who cares about that.

 

My 6 speed is smooth as silk... If yours is anything but that, then I would suspect something may be wrong. Most people know that the 6 speed is the better tranny...

 

Most people? Depends on your criteria for a better tranny, don't you think. The 6 sp is unquestionably harder to service, doesn't provide any better gas mileage, and doesn't have any better reliability, nor does it shift any differently than the 5 sp. in terms of smoothness. What it does have is the same issue that afflicts any transmission the more gears you put in it....they tend to hunt or shift more often and some people find that noticeable and even annoying. Try any of the Chysler 8 speed tranny's, it will drive you nuts.

 

Hunting for a gear? You have an 05 but sounds like the early 04. I don't know if the updated shift software would help. On my recent '04 purchase, I am getting better gas mileage. Tank average (same driving as my 01) is 22 (vs 20.5). Anyone that's driven a well maintained 5 is spoiled by the smoothest automatic in the universe. Any minor differences in shift quality on the 6 are going to be noticeable. On the 6, automatic upshifts (at 2,100) under moderate acceleration are pretty smooth. Worst so far (for me), is stop/start freeway (10-15). Gear shifts were obvious. Agree that I also prefer the 5. The invisible transmission is part of the legendary Lexus smoothness. 01-03 vs 04-06? Depends on the package and options. Good/bad on each. That's another thread.

 

In my '10 LS460 test drive, transmission seemed to be back to being invisible. Of course, there's a big difference between a test drive and actually driving a car for a couple of months. Still prefer a 430 for the luxury feel and quality build. Tranny smoothness def part of the picture.

 

I have had an 02 model 5 speed and at present I have a 04 model 6 speed. I prefer the 6 speed. It is just as smooth and it is not that much harder to service the transmission. Checking the fluid level from the bottom is not that hard to do if you have ever done any kind of work on cars. It also has a lot more get up and go than the 5 speed.

 

My '01 (5-speed, 272K miles) is a smoother shifting trans than any of my three 6-speed LS's (one '05 with 50K miles and two '06's). I can assure you there's nothing "wrong" with any or all of my LS's 6-speed transmissions - it's just how they shift - occasionally a little noticeable compared to the buttery 5-speed.

The discussion is incomplete without a comparison of the drive train specs:

Gear 5-Speed 6-Speed

1st 3.357 3.300

2nd 2.180 1.96

3rd 1.424 1.35

4th 1.00 1.00

5th .753 .73

6th N/A .58

Diff. Ratio 3.266 3.77

The extra (like an "overdrive") gear, and the fact that it's a lower ratio top end / final gear indicate the 6-speed should have slightly higher expected MPG (lower engine RPMs than the 5-speed for a given speed). The 6-speed's shift points in the lower (1, 2, 3, 4) gears are at earlier / lower speeds thereby getting into higher gear ratios sooner. And because of the lower ratio 6th gear, I find that my 6-speed LS's have higher top-end speed (before red line) than the 5-speed '01 LS. Both have plenty of torque.

What I really enjoy about the LS, whether it's the 5- or 6-speed, is that it blends the best of: (1) off-the-line and in traffic acceleration for a big heavy sedan, (2) it's a great high speed cruiser on the open road, and (3) it gets excellent fuel economy as well. There's usually some serious trade-offs in these three categories / criteria, and the '01 - '06 LS doesn't disappoint in any of them.

Edit: The differential gear in the 6-speed is also slightly higher than the 5-speed, which slightly offsets the lower final 6th gear in the 6-speed tranny.

 

Thank you Tom, for posting the transmission ratios and rear end ratios. That explains why the 04 05 and 06 accelerate better than the 01 02 and 03. And the 6th gear in the 6 speeds is a final drive of 2.19 compared to 2.46 in a 5 speed.

 

Really, tallcaguy? Interesting. I have not driven the '10 and up 460s. The few 07-08 460s I test drove all exhibited frequent shifting due to the 8-speed and the shift quality was very average...on the car's I test drove I certainly wouldn't categorize it as smooth, and way too busy of a transmission. I like the interior of the 460 but that transmission alone is enough to dissuade me from buying. I felt every single gear change and 8 gears is a lot to cross between stop lights.

 

Tom - thanks for the ratios and details on the 6 speed. My wife and friends couldn't figure out why I bought a big heavy 15 year old car. Everyone got a ride which included hard acceleration, full pedal 60-0 braking and some ultra quiet 75 mph highway cruising. No more confusion. My wife loves the recent 04. She's never driven 85 mph before. I've owned many cars. Never had one that I took out just because I like to drive it.

Father - my 460 trans comment based on a short test drive w/ only moderate acceleration. Best to refer to the 460 owners page for more useful feedback.

 

I am biased and think the 2006 LS 430 is the best LS Lexus has ever made and that is the main reason I said the 6 speed is better then the 5 speed. LOL... All of these cars are fantastic.

 

Recently had the transmission in our '01 fully drained, flushed, and refilled...... 16 qts of that precious fluid..... It was not acting up or anything but just due to have done.

Do not have an 04-06 to compare with, but we do have the 8 speed '14 LS460 and I prefer the ride/smoothness of the '01 over '14.... (my wife does not agree...).

Anyway you look at it, though, we are very lucky to have these cars and even a lot of the LS400 owners continue to sing the praises of these models. Even at 15+ years on our '01 it is one of the best cars I have had the pleasure of driving. Ride comfort, routine handing, power, and other arguable features makes it enjoyable....