Automatic 2-1 rough downshifting

wstar

This is going to be a very subjective thing, which is why we get conflicting reports about people feeling it or not, and whether they feel it only in M or only in D, etc. Aside from varying sensitivities in general, it depends greatly on the speed curve you're decelerating at with the brakes (or just coasting down at), and the force you're applying with the brakes at the time of the downshift.

If you get your speed down well in advance of a light (like you're trying to roll and wait for it go green and never stop, for instance), and then get off the brakes around 20mph and just let it coast all the way down from there to the 2-1 shiftpoint on its own in M-mode, you'll feel it for sure.

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molamann

I had the same exact problem with 7AT on "D" mode. It was actually pretty bad at first(first couple hundred miles,) bad enough so that I actually took it to two different Nissan service stations. Both of them told me that it's quite normal since the Z has such an aggressive transmission and it tends to do that coming to a stoplight at low gears. Anyways I don't know if I got used to it or if the transmission got better but it's lot less noticeable now at 3k+ miles.

frost

Thanks Mola, good to know it may get better.

wstar

Mine has been pretty variable. Sometimes I don't notice it for a day or two, then I get a really hard hit of this the next day. I don't think it's the car getting better, I think it's that I'm adapting my driving to avoid it more.

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frost

I'll keep my fingers crossed. I'm kind of regretting not getting the manual, but I remembered how much I hated the stick in traffic, so I went with something different.

wstar

Yeah it's a tough call. There are a lot of times I wish I had the stick instead of the 7AT. But on the other hand, flipping to D in traffic is convenient, and this is a daily-driver in a pretty congested city (not that I actually commute to work, but still). Being able to let a friend or girlfriend drive the car home when you've had a bit to drink is handy too.

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frost

I've been to houston many times (Family lives in sugarland), and I wouldn't want a stick there. We have bad traffic too, but it might just be worse there.

epod86

Maybe, I've always had the worst traffic with accidents on roads trying to get back into Houston. Then again, the first time I was in the state, 5 minutes after leaving the airport there was a bumper damage crash at speed. Everyone kept driving. My dad said that was why I was going to be costing him 2k a year in this state

I'm going to assume that the 2-1 downshift is rough because of the ratios. 1st is a 'pull away gear' that a manual user never downshifts into (street driving) because the ratio is really high. It's designed to get the car moving from a standstill, so the ratio is huge to get the torque to the stopped wheels.

The shift may be more noticeable because the Z is a 7 speed, and so it's relying less on the viscous and instead on making the shift to get the torque curves lined up than say a 4 speed. Then again, our hauler Commander really had some rough shifts at altitude from 4th to 3rd, followed by a very depressingly high rev as it weezed over the mountains.

I think that use will let you know how the computer thinks to try and avoid or mitigate the shift shock with time.

spearfish25

I live in Chicago with my 6MT. Our traffic can be horrendous, but I've made lemonade from lemons...bad traffic makes me get off on the back roads and gives me more time to drive home, enjoy the car, and zip through corners, turns, lights, etc etc.

epod86

Great suggestion

I've gone manual, and any 'fun' car will be manual, daily driver or not.

meleazar

"Misery loves Company" It actually might be a characteristic of the car. I have about 16,000 miles on it and the jerk is still there. I actually remembered that first jerk coming out of the dealership's parking lot. I was hoping that with a little wear and tear, this issue would eventually disappear. I know some say that they don't experience this jerk and others do. As WSTAR mentions, I do feel the jerk between 2nd & 1st mainly when I do slow decelererations, but if I pound on the brake, the jerking pretty much becomes non-existent. The thing that somewhat bugs me is that it doesn't always happen. Shifting D to M makes this jerk even more prominent, so I end up just upshifting with M and then I switch it to D for auto-downshifting. I actually flipped my first 370. God rest her soul She also had this downshift jerk issue between 1&2. Well anyway, thanks to Insurance and knowing that the safety features work well, I just had to get another one. This car is like a drug. To be honest, I think these cars were made to be driven hard. A very good buy for the specs and the price. I just hope these jerking issues we are experiencing though doesn't force us to replace our transmissions every few years. (fingers crossed)

Diocletian

When the car is coasting to a stop and I'm still in second I ease off the brake and downshift into first. Downshift Revmatch takes care of the rest, then I reapply the brake. Smooth stops every time! What ever you do don't downshift as you depress the brake, the car WILL lurch forward when it shifts and if you're to close to a car already it'll ruin your day.

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VCuomo

I noticed the same thing - for whatever reason, on the rare occasion when the car was new and would downshift from 2nd to 1st (and I'm talking "D" or "M" mode guys - it doesn't matter, since the car automatically downshifts when it needs to, even in M mode) it would really jerk. I've got a little over 10K miles on it now, you still notice it but not that much.

BTW, the jerk is normal. Try downshifting (at low speed, of course) a manual from 2nd to 1st and see what happens - unless you're barely moving you'll feel a jerk and hear the engine rev.

antman22

In my 7AT, like others have stated, only in M mode do i notice the sudden jerk. Its not that bad, but it is noticeable compared to a stop in D mode.

now i just pull the ebrake when in M mode.

kidding. kidding.

wilsonp

I don't drive in D very much, but I never have a jerk stopping. I don't think I see it downshift to 1 until I'm stopped, though?

OTOH, in M mode I notice a jerk more from 4 to 3 or may be 3 to 2, not 2 to 1.

I don't like braking late in traffic, but it makes coasting down difficult to do smoothly. I wish the SRM worked on the automatic down shifts as well to help smooth that out.

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