KLB

He mentions two different fixes. One for the downshifting and one for the high altitude.

RotaryRevn

Hi guys, I just wanted to give an update. My car now has 1300 miles and the problem is WAYYYY better. Now that 20 mph downshift is hardly noticable. It's still more noticable than every other car I have driven, but I can deffinately live with it. It doesn't bother me anymore. It's barely there. Now it just feels a little "sporty" where before it was just annoying as hell. I will look into that computer upgrade that someone else posted! Thanks for that.

G37beijing

Is your G37 RWD or AWD?

ChodTheWacko

iTrader: (1)

I have a g37x, and I feel the downshift but only because I'm paying close attention to it. I was driving around in manhattan with a carful of people and nobody noticed anything, it felt like normal braking.

- Frank

RotaryRevn

Mine is RWD. I am eager to get the flash upgrade next time I'm at the dealer.

TX_Driver

I've noticed issues on my week old '09 G37S Sedan. The transmission takes awhile to get the hint that I want to go when I push the pedal from a dead stop. It's not a good feeling when you're trying to get out of a jam or need to accelerate quickly to get merge into oncoming traffic.

I've also noticed that when I shift the gear shifter into "DS" (Drive Sport) mode and use the paddle shifters, the transmission will let me shift to the redline (not on purpose) and then the fuel-cutoff will kick in. It's not a good feeling (and it's a little scary). Does anyone know if there is a TSB on these issues?

Chris.

RedG37SNC

It seems like most of the transmission complaints are on new cars sub 3000 miles. I suspect once your engine and transmission break in things will smooth out. My 5AT has always been smooth as silk in D mode with gear changes unnoticable. In DS mode the large ratio change from 3rd to 2nd was definately noticalable since it causes the largest RPM blip as rev matching kicked in. These days at 15K miles the same RPM blip is much smoother and a welcomed sporty feel and sound, something I'd actually prefer on 4th to 3rd in DS mode as well but too small a ratio change. I'd bet most will notice things smoothing out after thier first oil change at 3750 miles.

For the throttle response issues, look into a grounding kit and possibly an intake upgrade.

PeterUbers

iTrader: (1)

technically speaking, a faster shift is better for the clutch packs anyway -- but i think a couple or more things are going on here:

1) people have different tolerances and/or definitions for what "normal" shifting is or should be

2) people have G37's with the 7AT that shift different than others... irrespective of the mileage..

G37beijing

In DS mode, there are actually two modes. If you just flip the shifter to DS without doing anything else, it becomes AUTO in sports mode. But if it's in DS and you change a gear using either the paddle shifter or the shifter, it becomes kind of pure MANUAL. This means you'd have to shift all gears manually, otherwise the rev will hit red line.

SkyMG37x

After reading this today I paid extra attention this afternoon as I was driving my week-old G37x with 350 miles. My observations:

• At highway speed (60+ MPH) and taking my foot off the gas, the car will coast just fine with very gradual decrease in speed. Nothing obviously out of the ordinary.
• At slower speed (35 MPH) and taking my foot off the gas, the car will coast normally while decreasing speed. I let it coast to 20 MPH where it downshifted to 2nd (foot off the brake) and it was noticeable but bearly. The car slowed more rapidly from that point but not what I would consider abnormal.
• While braking to slow down from 35 MPH, I would again notice the downshift from 3rd to 2nd at 20 MPH but again nothing I would consider out of the ordinary. I actually notice the 2nd to 1st downshift more at about 10 MPH.
• Earlier in the week I hit stop/go traffic on the highway where several lanes merge. The speed constantly varies from 0 to 30 MPH and back to 0. I didn't have any trouble in normal auto mode but actually preferred putting it in manual mode to keep it in 2nd then down to 1st when needed.
• Although I understand what's being described as "lag" when accelerating from a slow roll in normal auto mode, I find that there's a clear threshold in the accelerator where below that threshold the car reacts more slowly, but above that threshold the response is quicker. It appears that's because below the threshold the transmission is taking longer to downshift.

Maybe it's because I just came off a 6MT performance car that I and was used to keeping it in 2nd gear in the same traffic conditions I listed in my 4th bullet as well as rowing through the gears in a similar not overly aggressive fashion, but I don't find the gear changes in this transmission to be out of the ordinary for a performance car. It's clearly programmed in normal mode to conserve gas by moving to the highest gear as quickly as possible, and as noted the lower 2 gears have a greater ratio change. So far I love the way this car drives. But then again I still haven't gotten too aggressive with it.

G37beijing

The behavior of G37X could be different from that of the G37 RWD at slow speeds. My G37 RWD behaves much better at slow speeds when the A/C is running. I guess the slightly elevated RPM helps with the bogging.

Herkypilot

I now have 5,000 miles on my G-37 sedan and most of the shifts are smooth. I did some spirited driving this past weekend and the tranny had a few stiff downshifts from 3rd to 2nd. It was most noticeable when you get on the gas a little right at the time it downshifts from a deceleration. I'm back to normal driving this week and not much was noticeable other then I was going down a long hill at about 50 mph and was braking a little to keep from gaining on a car in front of me and the car downshifted and shot the rpm's up to about 3500. Not sure why but it stayed there until I took my foot of the brakes and then it upshifted to about 1800 rpms.

PeterUbers

iTrader: (1)

Was thinking of this thread and also did some spirited driving on the highway today (near 1000 miles now) and as per Herky -- shifts are smooth with the occasional 3rd-2nd "felt" shift (not a slam, jarring or anything like that -- it's just that I can "feel/perceive" the shift) and usually only when i'm in bumper to bumper traffic -- the '37 seems to gear hunt a little more ..

but WOW .. does this thing LOVE highway driving -- it just feels like it always finds the right gear and isn't afraid to downshift to squeeze every bit of hp/tq outta the engine -- i'm enjoying this car alot!! The G35x we have feels pretty flat on the highway, and our 2k6G35x is even flatter... (flat = more gradual, less aggressive acceleration)

RedG37SNC

What's really fun is aggressively braking in DS mode, not enough to skid but a good indication you want to come to a stop quickly and the car will downshift rapidly to engage engine braking. Had the opportunity to see that twice recently and with intakes and exhaust it's a rather loud announcement as it blips to 7K RPM that sometimes makes me think WTF!!! and then I realize the G's just doing what I couldn't possibly do at the same time as quickly. I'd imagine it does it in D as well, I just rarely drive in D and haven't verified that.

PeterUbers

iTrader: (1)

I'd be interested to drive a G37 coupe w/ the 5AT for comparison purposes...