Fellas, I just did my 15K service. I swapped the tranny oil to mobil 1 75W-90 synthetic GL-5, the tranny took 3 quarts. The dealer charged me $115 for the drain/fill and I supplied the oil.
I must say the tranny feels much smoother and I'm hardly getting the 1-2 gear notchiness(feels like it was grinding) its almost gone, you feel it off/on, not all the time like before, 3-6 slide like butter, especially 3rd gear.

On another note, I've noticed that my clutch sometimes slips. When downshifting from 6-5 at highway speeds and I get back on the gas, a second or two go by then I get a mild jerk like the clutch finally caught, can't tell if the RPM's are moving because of the darn revs hang for ever(I noticed this around 5K miles).
This morning I was merging onto the freeway on 3rd(around 3200rpm's), I pressed the gas pedal and the same feel that I get when I downshift from 6-5 was felt, I got off the gas a bit then hit the gas pedal again(not literally) and it did it again, backed off a bit and I felt it jerk again but that was it, I haven't felt it since??

I'm thinking the clutch is going, keep in mind this car is my daily commuter (Bay Area traffic sucks) and I do spirited driving sometimes but no racing.

Any ideas as to why it might be doing this, if this continues, I will take it back to Lexus for an opinion.

 

06LexIS, when you're shifting gears (up or down), do you match revs before letting the clutch out? If not, then it's not uncommon for the clutch to be worn out very quickly. Even as soon as 10-15K miles, depending on how much shifting you have to do. You'll know it's getting close to needing replacement when the clutch doesn't grab until the pedal is almost fully released.

A side note, I took my car in for the 5000 miles service last Friday, and brought up the rev hang issue, and the grinding into 2nd gear issue. As I expected, I get the car back with the usual "test drove the car, and found normal operation" explanation. I think a call to the corporate office is in order. Tired of these dealerships just getting away with whatever they please. At the very least, the more we let these guys know the problems with their current design, the better the chances of them fixing it for future models.

 

I'd be weary taking a stick car to be serviced at a Lexus dealer. Seriously, how many sticks have they even seen, judging from the fact that all the cars they sell are autos except for 1st & 2nd gen IS'. Moreover, even stick IS' are a rare breed.

 

That's the main reason why I knew they'd do little (if anything) to look into the issue. The tech probably didn't even know what I was talking about when I said "The clutch shudders upon takeup, when taking off in first gear". The main thing for now is that I get the problems documented in their system.

 

I had the same complaints and same response from the dealer...hopefully there will be a tsb on this matter.

 

The Scion tC has the same issues, and everyone likes to blame it on the drive-by-wire throttle, but when I put a light flywheel in it, all the issues disappeared. Front drive is a lot more sensitive to throttle ambiguity since a sudden drop feels like a brake stab.

The OEM flywheel for the tC is only 16 lbs stock, but replacing it with a 9 lb (yes, I weighed it) Fidanza transformed the car.

Since the only other manual I have is a Supra with cable throttle control, it's not fair to even try to compare it to any other Toyota. It actually has a pretty bulletproof gearbox in it and it works just fine with OEM or lightweight flywheels.

 

I believe the IS' problems have little to do with the flywheel. Here's my reasoning:

- When the engine is cold, revs drop very quickly. Much more normal.
- When revs are hanging, initially they drop "normally" for the first ~100 RPM, at which point they suddenly slow their decent, almost hanging in "mid air" as they slowly wander downwards. The OBC is obviously taking over between shifts to control emissions.

If this was a flywheel issue, then the revs would hang consistently, and all the time. I'm not saying that a lightweight flywheel wouldn't help, because I'm sure it would. But it shouldn't be at my expense that the car be made more driveable. A simple reprogramming of the OBC should be all that's needed. If this was a BMW, I'd actually have faith that a fix would be made available. Since it's a Toyota, I really have my doubts.

Bottom line, if this does continue, I'm positive that I won't own the car much longer. And I won't be wadering back into the Lexus dealer to buy something new.

 

That's exactly how my clutch acts. I get the clutch slip not only when downshifting , but just after upshift to 6th. I match the RPMs when downshifting and the clutch has engaged, but it's 2 seconds later I get the slip feeling 'lurch'.
I've said it many times in other forums that this clutch is a POS from the toyota parts bin. I had a Celica years ago that felt the same way--notchy, average throws, some shudder during breakin period, now the lurch or clutch slip noticed at 5k. I'm going in next week for my 10k service and will have it documented, but I know nothing will be done. I do all highway miles and put just over 40k a year on my cars and if this Lexus MT goes before 60k then Lexus will be getting an earfull. I'm glad someone else compared this clutch to the Scion TCs as they feel the same, but I wouldn't expect much for 18k but we've doubled that number with the IS.
As for the Rev drops, I'd say mine are average to a tad slow, but with the throw length, it gives it the time to drop. Now on a S2000 with such short throws, it may feel average but really it's dropping fast as you are shifting faster.... my $.02

 

Thanks for the replies, I try my best to match the RPM's but it's almost impossible at times. What I don't get is the replies I've recieved from Lexus "this is the first time we've heard of this", for now it's documented on my car.
I think all of us should get together and write a formal complaint to Lexus.
So far, the synthetic oil is working great on the tranny, yesterday I felt a shudder in 4th gear as I was slowing down on the freeway(traffic), weird..
I'll keep you posted, maybe we need an aftermarket clutch/flywheel

 

I had a slip in 4th gear this morning. Downshifted into 4th easily, let the engine slow the car down, running from 4 to 3rpm, then cruised for a few minutes at 3kRPM in 4th. Went to accelerate, not to the floor but half-way, and it slipped.

It's random is all I can say.

 

I already plan to contact them about the issues with the manual transmission. Otherwise, then they'll never do anything about it.

 

ff, let me know what happens.