7 A/T Question
 

Anyone that used to have a 350Z A/T notice a big difference with the timing on the 370Z's 7 A/T? It seems to me like it takes longer to upshift and hangs out in the gear a little longer than the 350. I also notice a big difference in it's downshift as well, slowing the car down almost like it's braking when it does downshifts at a light or making a turn. Anyone else notice this?

it does take long for the upshifts. often if I start it goes up to 4500 rpm before shifting.

didn't notice the downshifting problem.

i can't compare to the 350, but the upshifting can depend on how much of a lead foot you have. i think the timing of the upshift can vary depending on how aggressive you are, because i think it adjusts itself as you drive. so if you're driving with a light foot, it'll shift earlier but if you're constantly mashing the pedal, it may hold the gear longer.

as far as the downshifting, i have noticed that. not sure why?

A few videos that I took demonstrating how odd the Nissan 7-speed transmission is. This is my '09 FX35. It needed a transmission reflash, and it made the transmission a little less jerky, but you still notice that it's very busy. Here's a few examples of how it goes into this really "low-revving" mode. I'm sure you AT'ers have noticed this before. It's long, but I just wanted to demonstrate it. If you have jerking in your transmission when you're slowing down or it holds gears longer, this is completely normal for Nissan/Infinitis. That's how they're designed and programmed.



Now here's a video of it running normally.

now when i'm slowing down, i usually just let off the throttle and the downshifting provides enough braking...unless i need to make a full stop.

I have no clue if this was ever a TSB on the 370, but it was with a limited number or FXes. When I bought my new FX, it would actually jerk my head forward when slowing down. I had the TSB tranny re-flash, and it calmed that behavior down a little, but you still can tell it's downshifting when coming to a stop. With the new 7-speed transmission, Nissan/Infiniti started with this reprogram, but I don't know if it carried to the first Zs. All newer 7-speeds will come with this reprogram from the factory.

My second video is how the transmission normally works. I never grabbed a video before my reflash.

Is this magical re-flashing of the transmission something that is covered by warranty or something I will need to lay down some $$$ for?

the slowdown isn't jerky, it doesn't make my head go forward, but i can tell when its downshifting and there is a slight "lag" in motion i feel. similar to if i very lightly tapped the brakes. a little difficult to explain, but its there.

I really wouldn't call it magical, nor do I know if there's a TSB for the Z. This happened to some of the first FX's that came off the lot. Even after it, I still feel the slight "drag/lag" when slowing down like Ant talked about. If someone has records of the Z's TSBs, let mwilli know, but as far as I can tell, it will still "drag" mildly when slowing down. It seems to be part of the 7-speed design. It won't hurt the car. Mwilli, I'll sum it up by saying that there's a good chance there wasn't a TSB in the Z. I think it was fixed by the time the car was released. It's just a quirk.

If there's not a TSB on the Z, it's the way the transmission is. You won't make any progress by bringing it in IF there's no TSB.

That is exactly what I'm talking about...no whiplash or anything funny like that, just a light tap on the brakes, which I would probably feel downshifting a manual.

Dumb question to follow...what is TSB an acronym for?

Nevermind...Google knows and sees all things...I'll check the database it found to see if there is anything for the 370Z. Thanks all!!

Technical Service Bulletin. If you're under warranty, and you have a particular problem that's covered by a TSB, it will be free and fixed with instructions from the factory.

I don't really feel the downshifts when breaking or letting go off the throttle only issue here is that it reallyyyyy takes a long time before it upshifts

sometimes at 4000rpm or 3500rpm.

comparing it to the GTR automatic it IS odd. the GT-R if your accelerating slowly it still shifts at 2000rpm

That's my thought exactly...really comes into play from 2-3 and from 3-4 IMO. There's no TSBs on Nissan's website for anything regarding the issue.

I don't see any of the issues described in my car and my 370Z shifts a LOT faster than my 350Z did. There is no comparison.

+1

Seriously I think alot of these types of questions are posted by people that have never driven a 370z. The 350z is a nice car, but it is not a fast car at all compared to most stock sports cars. The 370z holds it's own against any stock car. And the AT in the 370 is far superior to the 350's AT which was a pig in all respects. Heavy slow and a power hog.

mostly 1-2 and 2-3 that have the problem well "problem" I don't mind

um, the 5AT in the 350Z only weighed about 10 to 20 lbs more than the 6MT. Heavy it ain't. Shifting speed was at least average to good as opposed to the 7AT's best in class. It was a very light AT for it's time, just needed at bit faster shift times (fixable with a shift kit). It's downfall is not being able to hold power past about 400 WHP without having problems.

Here is a quick link to some curb weights.... http://www.350z-tech.com/zwiki/Weight_Reduction_Guide

7 speed is so many gears and so many things that can go wrong...automatically.

I too, feel this...just assumed (hoped!) it was normal!

^i also think jerky is too strong of a word. you can feel the downshift, but it's not bad at all. sometimes it gets near the "jerky" borderline but i think it's normal.

i've come to terms with it and say its a feature of the Z. Automatic engine braking. Allows you to spend less time on the brake pedal :)

don't you always engine brake when downshifting?

I mean here they tell you that you should always engine brake

6 cylinders cars have more engine braking than any 4 cylinders cars,in real world driving a v12 will even have more engine braking,than our Z.

Both my Z and my Frontier do the same thing as shown in the video.

OMG, the world is fail.


Seriously, it's an economy-mode program. Lower RPM = Less Gas used.

the only real problem I have with the AT set in manual if I downshift too slow I do a double shift and the engine flies up to 5000RPM

not fun if you are driving down your street at night.

Yes I know that it is just me not shifting quick enough but bleh

slowing down wanting to downshift to third but a fraction of a second before me it already downshifts making me go from 4th to 2th.

loud engine is loud