Hell, even my GS350 with the 8 speed will do this (to a softer extent), I presume since that transmission is a derivative of this one mated to our V8s. It’s just the way they are. Occasionally a little clunky, but generally bulletproof.

 

My '15 RCF also does this; was told it was normal when cold and will improve once the trans warms up. You'd think the rough shifting would have been improved almost 9 years later but nope lol.

 

My 2015 GS350 (8 speed RWD) does NOT do this at all.

 

It only really happens if I don’t come to a complete stop when it does the 3->1 or 2->1, and it’s pretty much exactly like the IS500 like that. Downshifting into first while still in motion is just jerky in a lot of older transmissions.

I have a buddy who used to own a 2015 IS350, and he noticed the exact same thing. I mean, it’s not as jarring as this car and it happens less frequently, but the version of this transmission for the 2UR-GSE seems to be programmed to engage its gear change clutches a good bit harder.

 

Yeah it does shift hard. My car will go sideways if I shift in a turn. And now with colder temps (still 60s here) even like 50% throttle and manually shifting around a bend will kick out the rear and trigger the traction control. When it's hotter and dry it will chirp the tires on the 1-2 shift. It's really freaking fun when it's not dangerous lol

 

Yeah my IS 350 (same trans as your GS 350) didn't do the same thing as my IS 500. It only rarely would clunk into first gear when slowing down in auto, but I mean RARELY - like once every few weeks. The IS 500 is doing this clunk at least a couple times on an average errand trip.

The 1-2 tire chirp is addictive, I have to say.

The transmission shifting really quickly doesn't explain the low-speed downshift issues... One thing I've done to work around it is manually downshift. However, that can be sorta rough in a different way. If the revs are too low, the engine RPMs do not come up to meet the speed of the transmission (no rev-match, basically), so I get little lurches on each gear change. It's a bit less rough than the clunk that would otherwise occur, but it doesn't feel great, either. I just have to cross my fingers and hope it doesn't do it.

 

Wow this is very different than my experience. Manually downshifting into 1st (or even 2nd) as I slow to a stop lurches the car hard. It's a real neck workout. That's true when the trans is warm. I don't do that much when the trans is cold, so I couldn't say how different it is then. I feel bad when I have passengers but it's annoying as heck even when I'm driving solo and I know it's coming.

 

Again, the car is smoothest when you’re in M and you don’t do anything when braking. Try it.

 

Incidentally, I tried this yesterday, and I can confirm this. I didn't get lurches.

 

You don't get lurches and you don't get transmission clunks. It proves the transmission noises is purely software based.

 

It looks like I'm an outlier, my car hasn't lurched in like a year. After driving it about 5k miles, it now comes to a stop just fine in all driving modes as long as it's warm.

 

So I think the low-speed deceleration clunk has something to do with the torque converter lock-up. I watched the Gear Position display as it happened. Every time, it was in 5th gear, and there was a separate jump in RPM for downshifting into 3rd.When I'm in manual mode in second gear, at around 22 MPH I can feel a similar hesitation or clunky feeling, every time. I'm guessing it is the same thing, but in reverse?

Anyone else seeing this?

 

Maybe I should have been more specific. I'm not referring to lurches when the car auto-downshifts. I'm referring to manual downshifts triggered by the paddle.

Yesterday I deliberately did some testing of flappy paddle shifting in manual mode vs. flappy paddle shifting in automatic. Downshifts seemed smoother in M mode (when comparing shifts to the same gear, at similar rpm), but I would classify that testing as "anecdote" not "data".

 

As far as I can tell, there's no difference between downshifting behavior with the paddles in D or M. It's all dependent on RPM. This thread doesn't really have to do with the paddles.

Can anyone else please respond to my post above? I'm trying to see if it's something all our cars do, or just mine.

 

Yes I am pretty sure I experienced this as well. Since adding my mid pipe and new exhaust, the car performs differently and these things you mention Arentz are gone. As it was for me anyway, they were subtle to begin with. The new things that are happening is the shifts are smoother, yet more pronounced. I get this awesome subtle back draw from the engine as it shifts from 5th gear where the issue you mentioned once occurred. I am of the opinion, a lot of tangibles effect the ECU for this car given it's parts and pieces are from various models. At the end of the day they married alot of things together and these subtleties have some effects that we scratch our heads with. I guess what I am saying, I never expected the exhaust modification to have a profound effect on shifting subtleties like it did. The overall mod was a drastic improvement to alot of areas to the car, which I could explain better in person than writing out. The only thing I miss previous mod exhaust is having a stock quiet option. When the valves are closed, it is quiet but not like it was stock. Not trying to make your question Arentz about exhaust, just pointing out the issue you mentioned went away or should I say became very smooth with my exhaust change.