2019 5.3l 8 speed jolt when accelerating

ShamrockShooter · May 13, 2019

I have been trying to ignore the first shift or two every morning. This morning I backed out and thought let me give it some gas instead of light throttle like I normally do. It had a huge hestiation on that first shift to the point it felt like it went into neutral and my body actually lunged forward in the seat before it slammed into 2nd. Felt like a 16 year old bucking the clutch on a manual. After that first shift it was back to normal.

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ILSilverado · May 13, 2019

57 minutes ago, ShamrockShooter said:

I have been trying to ignore the first shift or two every morning. This morning I backed out and thought let me give it some gas instead of light throttle like I normally do. It had a huge hestiation on that first shift to the point it felt like it went into neutral and my body actually lunged forward in the seat before it slammed into 2nd. Felt like a 16 year old bucking the clutch on a manual. After that first shift it was back to normal.

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What happens is and I know this from the Corvette forums over night the fluid drains back out of the torque converter so in the morning it just doesn't have enough fluid to give a proper shift. On the Corvette you can start the car first time and use the paddle shifter's to go from 1-2 and back again a couple times before selecting reverse or drive and doing this pressurizes the system enough to get a smooth 1 to two morning shift. Unfortunately we don't have this option on the trucks. You would think after 5 years GM would have come up with a fix for this.

ShamrockShooter · May 13, 2019

It seems to be the worst when I park on my steep driveway engine uphill, then back out of the driveway. It hardly ever does it when it sits at work for 10 hours on level ground and put it straight into drive after startup. Also seems much worse when temp falls below 45.

But GM says it won't affect performance or longevity so we are forced to just accept it as is and move on as long as it only does it the first shift or two if the day.

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econometrics · May 13, 2019

8 minutes ago, ShamrockShooter said:

It seems to be the worst when I park on my steep driveway engine uphill, then back out of the driveway. It hardly ever does it when it sits at work for 10 hours on level ground and put it straight into drive after startup. Also seems much worse when temp falls below 45.

But GM says it won't affect performance or longevity so we are forced to just accept it as is and move on as long as it only does it the first shift or two if the day.

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Start parking backwards on your inclined driveway. ?

I backed into my inclined driveway and parked over night last night (not to help the trans, just for some other reason), and I actually noticed my shifts were SUPER smooth this AM.

So yeah, maybe this has something to do with oil getting into the torque converter?

ShamrockShooter · May 13, 2019

Start parking backwards on your inclined driveway. [emoji16]

I backed into my inclined driveway and parked over night last night (not to help the trans, just for some other reason), and I actually noticed my shifts were SUPER smooth this AM.

So yeah, maybe this has something to do with oil getting into the torque converter?

So there you all go. I solved the problem. That was easy.

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mookdoc6 · May 13, 2019

On ‎4‎/‎29‎/‎2019 at 6:39 PM, Bmwtech113 said:

I have a 2019 AT4 with the 5.3l engine. I’ve had it for about a month now and I have noticed especially when I first take off after the truck has been sitting for a few hours that there is a jolt that will happen multiple times while accelerating up to speed. I’m not flooring it, just accelerating normally. It occurs between 10 and 50 mph and once it warms up then I never notice it again. Happens in D and also if it put it in L7 or L8. It feels like either a misfire or the transmission slipping. I just picked it up from my dealer tonight after they said “we’ve had other complaints but that’s just how it is.”

Has anyone else experienced this?

You should have "firm" shifts on warm up...after that it goes away? It should even be stated in your manual I believe has to do with warming the fluid up quicker and reducing wear on components....

Bmwtech113 · May 13, 2019

2 hours ago, mookdoc6 said:

You should have "firm" shifts on warm up...after that it goes away? It should even be stated in your manual I believe has to do with warming the fluid up quicker and reducing wear on components....

My main issue has nothing to do with shifting. Maybe I am describing it inaccurately but it is like a transmission slip that occurs multiple times over the course of a few seconds or like a stutter. It happens during acceleration from around 10mph up to 50 mph but not at shift points. If it were an all-wheel drive BMW I would say it feels exactly like the transfer case is slipping but I'm not sure the 4x4 system on these trucks works the same as the BMW all-wheel drive system.

ShamrockShooter · May 14, 2019

Start parking backwards on your inclined driveway. [emoji16]

I backed into my inclined driveway and parked over night last night (not to help the trans, just for some other reason), and I actually noticed my shifts were SUPER smooth this AM.

So yeah, maybe this has something to do with oil getting into the torque converter?

Nope. Backed in last night. Still had hard 1-2 shift this morning.

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econometrics · May 14, 2019

51 minutes ago, ShamrockShooter said:

Nope. Backed in last night. Still had hard 1-2 shift this morning.

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Well that's disappointing. At least you tried!

My 8 speed has been unusually amazing the past week. I'm not sure if it knows how badly it's being talked about or what. Lol

Bmwtech113 · May 20, 2019

Ever since the new fluid, I have not had the exact issue I originally had which was when going up a hill on a cold start the drivetrain would jolt or buck about 3 or 4 times in about a 5 second span.

I took the truck back this past Saturday for a harsh 1-2 and 2-1 shift. They basically told me it was normal and I have to admit the loaner truck felt the same at times as far as the 1-2 and 2-1 shifts.

However I still get a random jolt from the drivetrain. It doesn’t appear to be when shifting but it is at lower speeds between 10-50mph. The drivetrain on this truck in general feels like at times it doesn’t know what it wants to do and gets confused causing a rumble or clunk type feeling. Some of that may or may not be the DFM. One thing I did notice is that on the loaner they gave me (a Silverado LTZ 5.3) the engine rpms seemed to stay higher than what the rpms are at the same speeds on my AT4.

Bmwtech113 · May 21, 2019

Well I spoke too soon about my original issue being fixed. It happened today. Going about 15-20mph through a neighborhood at constant throttle I felt a shudder and could even see the rpms fluctuating as it was happening. I’ll be back in touch with GM tomorrow.

DaveHC · May 24, 2019

mine does it to, also seems to take a couple seconds to go from reverse to drive, after the first 40 feet its fine.

whatsnext6.2 · November 22, 2019

You have TCC shudder. hopefully they replaced it for you. i cant believe its made its way all the way in to 2019's.

whatsnext6.2 · November 22, 2019

http://gmauthority.com/blog/2019/08/tsb-seems-to-fix-8-speed-automatic-gm-transmission-problems/

Im gonna guess most dealers arent flushing the fluid on trucks sitting on the lot that haven't sold yet. And if they did i would bet they used black label and not blue label.

Tom Regal · December 3, 2019

On 4/29/2019 at 8:39 PM, Bmwtech113 said:

I have a 2019 AT4 with the 5.3l engine. I’ve had it for about a month now and I have noticed especially when I first take off after the truck has been sitting for a few hours that there is a jolt that will happen multiple times while accelerating up to speed. I’m not flooring it, just accelerating normally. It occurs between 10 and 50 mph and once it warms up then I never notice it again. Happens in D and also if it put it in L7 or L8. It feels like either a misfire or the transmission slipping. I just picked it up from my dealer tonight after they said “we’ve had other complaints but that’s just how it is.”

Has anyone else experienced this?

I have the same exact problem with my 2019 GMC Sierra.

The dealer told me GM will not pay for any repairs on this. UNBELIEVABLE !

I would never by another GM product and I suggest otherS to beware.