Walt White Coupe

Not interested in pros & cons from a driving standpoint of shifting the A8 into neutral while coming to a stop. But I'm curious about what is going on when I do it.

Say I'm coming up to a red light and I know I'm gonna have to stop. If I push the shift lever into neutral while I'm going 20 to 30 mph, the car coasts but just as the car stops I feel something in the transmission disengage. Now if I wait for the car to stop and push it into neutral, it acts like every other automatic transmission I've ever had and simply goes into neutral without any feeling in the car of disengagement.

Any thoughts?

Walt White Coupe

Has anyone else experienced the same "disengagement shake" once the car stopped if dropped into neutral before stopping?

owc6

Can't say as I've ever tried that on this car, but will check to see. A6, but hey!

Steve_R

I've never done that with any auto trans car I've owned, so not sure. Dunno why you'd do that.

Kevin A Jones

I was wondering the same thing myself.

Vetteman Jack

Don't really see the point in it, but maybe the OP has a good reason.

sunsalem

Me too.

Walt White Coupe

My request clearly stated that I don't want to get into a debate about why I like to be in neutral at a stop light.

What I want to know is:

1. Is this normal?

2. What's actually going on in the transmission since I've never experienced this with other automatics.

JerryU

Hmm, never tried to do that when driving the wife's automatic cars. Assume the OP is hearing a gear clutch pack disengaging, which in addition to shift lever position is speed dependent?

Just a thought, an automatic doesn't have a heavy flywheel like a standard trans that helps keeps it running smooth at idle. The toque converter provides some of that function when under load, i.e. when in gear it slips when stopped. That is one reason to buy a slush box!

Assume GM designs the system assuming it will be in gear when stopped. Just responded to a comment about an "as delivered" car's rough idle. I posted, similar to others, that it's a high performance engine and doesn't idle like a Honda!

Curious what others who have an automatic Vette and try, find what the OP observes.

Kevin A Jones

Seems you may have difficulty finding if the results of an abnormal procedure is normal.

NSC5

In neutral the C1 and C2 clutch packs are applied when there is no load on the drivetrain but release in neutral under load and as you transition from rolling to stopped there will be a change in drivetrain load.

The only time I shift into neutral is sometimes in hot weather stop and go driving at a light I will bump the shift selector up into neutral which reduces heat contribution from the transmission and slightly increases engine idle speed which slightly improves AC operation. But this is a rare event for me and probably unnecessary in the C7.

Letting the transmission do its normal thing while coasting down to a stop takes some of the load off of the brakes. And although you are unlikely to have an issue given the low miles most owners put on Corvettes the 8L90 internal mode switch (its equivalent to the older and simpler neutral safety switch) still uses a mechanical switch section as the starter safety switch so I guess over time you might manage to wear it out given the engineers never envisioned the high level of switch actuations you are causing. The remaining parts of the IMS use Hall effect sensors so they aren't subject to mechanical wear.

davanz

Walt, I sometimes shift my auto trans vehicles into neutral at long stop lights.

If it is on a level street where I do not have to hold the brake to keep it from rolling, I sometimes also do not want to hold the brake to prevent it from "creeping" while in drive. Just easier to slip it into neutral. Some stop lights in my area last a long time. Next time I have my 2016 A8 out I will try what you described and see if I detect anything.

L8ter

After reading your post Walt I went out and tried what I think you were doing. I put my transmission into neutral at 30 mph while coming to a stop. There is complete disengagement, and no reengagment.
I hope this answers your question.

bjones7131

I do it on my DD chevy truck and nothing unusual happens. I do it on occasion when the engine is cold at the end of my driveway to rev the engine just to speed up the warm up. Not a vette but this is my story.

Walt White Coupe

I didn't say there was "re-engagement". When put into neutral while moving the transmission goes into neutral. But as soon as the car actually stops, there is another very noticeable "disengagement" or at least that's what it feels like in the car to me.

Mike Mercury

I tried this today on my '15, same thing. Right before coming to a full stop, I do feel something.

same here; when going into N after a full stop, felt nothing.

Rebel Yell

I've never tried that Walt, but I will put mine into neutral when stopped at the "all day" stop lights sometimes. Anywho, you now have me curious, so I will give your method a try next time just to see what happens.

Walt White Coupe

So I was just out and decided to make it do it's thing to see if I could describe it better. While the car was cold it didn't seem to happen. And I never got the car really warmed up but just before I got where I was going it started to exhibit that what I will now call a very slight "clunk". I think it would be worse if I let the car & transmission really warm up. But a critical piece of information. It doesn't happen "immediately" when the car comes to a stop (and surely not before it stops), but about 1 sec after the car actually stops. So Mike what you are feeling must be something else.

Johnp94

I've always done the same in my Camaro. I bought my 2014 c7 3 weeks ago and I occasionally do it. I'll check into it later or tomorrow.

cv67

was always told by my trans guy to never do that, when you hit N the inners keep spinning , if you go to dump it in D again could cause damage
Are the ones in the C7 like that who knows not something Id make a habit out of personally. Not a technical answer thats all I got.