Redfox

My 7 speed automatic transmission was placed in my 2009 G37 Journey Sedan 08/08.

From the start I experienced the sharp down shifting problems at approximately 30 mph and then again at aproximately 20 MPH.

Had the reflash done to the transmission and it by and large smoothed out everything. No noticable downshift at the above mentioned speeds.

Oddly enough though, I do on occasion experience a slight rough downshift at 15 MPH when coasting in for a stop. However, it doesn't happen each and every time. Just now and then. Must be just the wrong amount of gas/de-acceleration/brake combination that sets it off. Anyone else out there experiencing something similar?

On another note, I also have experienced the hesitation/power surge on acceleration problem. Press down the accelerator just a fraction of an inch too far and too rapidly and the the engine becomes a howling banshee and takes off like the after burners have kicked in - slamming my head back into the headrest. Turns a few heads in my direction, (including law enforcement I might add!) and I believe that overall it reflects badly on the image of the automobile. Would be OK if I were 18 once again I suppose.

All things considered, I can live with the 7 speed transmission the way it now is. It gets me 22 MPG city and 30 MPG highway, so I can't complain too much.

maxfinity

When I first purchased the car I absolutely hated the transmission. It felt like it was always switching gears. But after 1 1/2 years and almost 30k miles of driving I have no issues with the transmission. Either I've learned to work with the quirks or they have basically ironed themselves out. Every blue moon I'll notice some hesitation or a rough shift and I do about 60 city and 40 highway. I drove my friends 07 g35 sedan and the gas pedal on that car is noticeable more sensitive then my gas pedal( I have a 2010 sedan/12-09 bulid date) which I didn't like. It felt a little too sensitive. I also get about 22 mpg combined which is much better than my Maxima which was rated to have better epa ratings and had about 63 less horses under the hood. I also get better mileage than my friend who has the 07 sedan and he does about 60 city and 40 highway. I have not had any TSB's applied for my tranny. To each its own. It's definitely not the best Transmission but IMO its far from the worst.

jb606

There is some kind of software problem that Infiniti needs to get right. It seems like (I'm not any kind of expert here) a lot of the harsh gear changes are caused by the torque converter not completely unlocking, then locking too quickly after the gear change. Pay attention to how the car changes gear, you'll see the tach drop twice after a gear change. The first is gear change, the second is the converter locking up. In my G the "bang" I can feel is when the converter locks up.

In older cars the converter wouldn't lock up until you were in top gear, the G will start locking the converter in second (In D you get "slip lock" from gears 2-7 with full lockup in 7th. Manual mode is full lock in 2-7)

mw09g37

iTrader: (3)

7AT is never in the power band. I'm in DS mode with my hand on the downshift every time because of it.

and I've never gotten anywhere near 22/30... I mean if you get that. damn you're lucky. or you're grannying it.

i get closer to 12/24 avg 16-17

6mtg37s

iTrader: (1)

Drive a cvt in NYC.. I don't think gears are convenient there.

6mtg37s

iTrader: (1)

But then again I think any car without the third pedal has a problem!

Hellcat716

Had my torque converter replaced on my 2010 G 37 and has cured all of my transmission problems. Am very satisfied with the car now.

Igorsky

Really? what problems with the transmission were you experiencing???

devil2k

Yes there are issues but not serious enough for me to complain about the 7AT. There's no option for it so I didn't vote.

awais

iTrader: (4)

Very interesting. What did you tell the dealership that they replaced your torque converter.

norcaldave82

I have a 2011 IPL and the DS mode is so aggressive that while on winding roads I am at almost 5k RPM constantly. When on the freeway in 7th gear it does rev higher, that is what I have noticed. Hope that helps lol

maxfinity

My car has been at the dealer for the last two days so I have an 09 loaner. It has about 25,000 miles on it and I must say if my transmission behaved like this car I would be highly disappointed. The lag is very noticeable on this loaner. I've had previous loaner cars and none have had so much lag. I'm starting to think that some cars may have had some faulty transmissions. Im glad mine wasn't one of them.

HappyG

Please do this experiment. Reset your loaner's ECU by disconnecting the battery. After you reconnect the battery, try to drive it aggressive to see if the lag is still there.

If it still lag, then there must be something wrong with the transmission as you experienced. But if it is much more responsive, then I think it could be a software programming issue that can be fixed without replacing any hardware.

Mike S.

Look at the percentages...while this group on this forum may be picky-er than the average population, 30% is a HUGE number when were talking about a problem. That's 1 in 3 think there is something not right with their tranny. And guess what, they're right. This stuff isn't in our heads, the tranny is quirky. Me thinks that ALL the trannys are the same, and the others just don't find it annoying. I've driven SEVERAL g37 loaners and they're all the same.

Even my friend (a girl who doesn't know much about cars) recently (last 6 months) got a G25 7AT. The day she said she loves the car but asked "why does it jerk sometimes when I'm comming to a stop?"

The 7AT could be a really good tranny.

I think its all the software. That, and the adjustable torque converter (TC). Its not just that the TC can lock in gears 2 through 7 (something like that) but that the locking is adjustable in how much it slips. I don't even understand why that is necessary..but its how the system works.

Combining the throttle inputs, so many gears and variable locking torque converter is somthing Nissan/Infiniti has just not worked out yet. Lags, rough downshifts, flares, etc...

rlo

I am going to agree with you there Mike S. It is too coincidental that almost all G auto owners know what you are talking about when you mention the tranny.
And all service advisors have an explanation or response when the issue is brought up, so that pretty much says it IS an issue that Nissan/Infiniti has yet to completely resolve.
I think only when people start getting into accidents (i.e. Toyota throttle) and the info makes it into the news will they look into it.

Hmmm, anyone here work for the media?