[10at2017zl1]

Hello everyone, new guy here got an issue on the '17 10AT

Last 2 Mondays, when reversing out of my garage and shifting into drive, it’s taking about 5 seconds to engage the gear (D), and then producing a loud thud and lurching forward.

Unseasonably cold winter here in LA, car usually sits on the wknd bc my gf hates the racing seats so we usually Uber or take her car on the wknds.

Don’t notice day to day during the week, will be hard to replicate at the dealer since it’s only happened twice (after sitting 2 consecutive days last couple wknds). Short of a recall or bulletin, nervous to turn it over to dealership. Found this online but it pertains to the 8 speed https://gm.oemdtc.com/6777/16-na-019...hevrolet-gmc/4

No noticeable issues when driving. Around 2500 miles, driving the car w/ respect (no abuse). Thanks for the free advice

[Can'tHave2MuchHP]

From 8 speed experience, usually a dealer will try a trans update and if that doesn't fix it, they'll order a new trans. That may not be the same procedures for an A10 but it's worth a visit if you have a good dealer.

[SLO]

is this with time to warm up a bit? Or immediately moving right after starting up?

I have no issues like that with mine but I do give it a minute or so before moving the car so im curious. My car sits outside in the cold Colorado weather.

[10at2017zl1]

Yesterday I let it warm up about 30 seconds, certainly not very long, today same amount and no problem.

[likerage]

Originally Posted by 10at2017zl1

Yesterday I let it warm up about 30 seconds, certainly not very long, today same amount and no problem.

In Colorado with single digit weather I have not had this issue and I don't sit for more than a few seconds after starting the car. You shouldn't need to warm up the car to get it in to D in LA.

[10at2017zl1]

I'd be lying if I said I was thrilled about the issue, was part of my reluctance on the car ('17) as it was the first production car with that transmission.

My out of state friend who was a master mechanic thinks it's the adaptive shifting and the fact that I'm going slow as a turtle most of the time (LA traffic) with a small percentage of performance driving. He's attributing it to pressure dynamics and confused solenoids.

[jimmypop13]

Originally Posted by 10at2017zl1

I'd be lying if I said I was thrilled about the issue, was part of my reluctance on the car ('17) as it was the first production car with that transmission.

My out of state friend who was a master mechanic thinks it's the adaptive shifting and the fact that I'm going slow as a turtle most of the time (LA traffic) with a small percentage of performance driving. He's attributing it to pressure dynamics and confused solenoids.

That doesn't sound right to me. If a car got confused shifting into gear because you drove in traffic, GM has some serious problems

[rjacobs]

Sounds like low fluid to me...

[10at2017zl1]

Just got the diagnostic email from Chevrolet today, all green checkmarks, no issues found

Suppose they could check the fluid level next oil change, it's coming soon

You take a risk anytime you buy a vehicle in its first model year

[camaro5]

Originally Posted by 10at2017zl1

Hello everyone, new guy here got an issue on the '17 10AT

Last 2 Mondays, when reversing out of my garage and shifting into drive, it’s taking about 5 seconds to engage the gear (D), and then producing a loud thud and lurching forward.

Unseasonably cold winter here in LA, car usually sits on the wknd bc my gf hates the racing seats so we usually Uber or take her car on the wknds.

Don’t notice day to day during the week, will be hard to replicate at the dealer since it’s only happened twice (after sitting 2 consecutive days last couple wknds). Short of a recall or bulletin, nervous to turn it over to dealership. Found this online but it pertains to the 8 speed https://gm.oemdtc.com/6777/16-na-019...hevrolet-gmc/4

No noticeable issues when driving. Around 2500 miles, driving the car w/ respect (no abuse). Thanks for the free advice

Lack of fluid in torque converter and/or clutch pack(s).

They drain when it sits and then must "refill" circuits and/or TC.

h

[10at2017zl1]

Great, thanks for the explanation camaro5. Should any action be taken?

[kwav8r]

That's not normal and should not be happening. I live in PA, and even when cold soaked I don't have that problem on cold mornings. Sounds more like a low fluid condition.

As for the OnStar 'diagnostics', I don't believe there is any sensor within the transmission to report fluid levels. The only way to check is that the transmission be brought up to operating temperature (209F?) and the fill plug pulled to see if it is properly filled.