2019 5.3l 8 speed jolt when accelerating

Bmwtech113 · April 30, 2019

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?

steve841 · April 30, 2019

Read an article earlier ... someone's filing a class action suit because GM cant get the 8 speed working correctly ....

HondaHawkGT · April 30, 2019

1 hour ago, 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?

Is it a shudder while accelerating in a gear or just when a shift occurs?

If it's a shudder, then there's a new fix for it. It's incredibly annoying that some dealers will play stupid, making comments like "that's just how it is".

TSB #18-NA-355

Print this article out and hand it to them:

https://gm-techlink.com/?p=11127

Here's a simple explanation of why the new fluid is the real deal:

"The base stock of old fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

Edited April 30, 2019 by HondaHawkGT

RMR · April 30, 2019

I have the 6 speed. On occasion, the torque converter will slip a bit on the 2-3 shift under mild acceleration. Feels like it disengages for a moment - engine spins up a smidge - then it re-engages. Only section of the drivetrain. Under no other conditions.

Bmwtech113 · April 30, 2019

12 minutes ago, HondaHawkGT said:

Is it a shudder while accelerating in a gear or just when a shift occurs?

If it's a shudder, then there's a new fix for it. It's incredibly annoying that some dealers will play stupid, making comments like "that's just how it is".

TSB #18-NA-355

Print this article out and hand it to them:

https://gm-techlink.com/?p=11127

Here's a simple explanation of why the new fluid is the real deal:

"The base stock of old fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

The issue I’m having occurs while accelerating in gear, not while shifting. According to the article you posted, it doesn’t apply to the 2019 Sierra/Silverado. Can you confirm that it actually does apply to my truck?

HondaHawkGT · April 30, 2019

If it were my truck, I would try it. Notice that the 2019 Colorado and Canyon are covered under it. It's possible they used the old formulation of Dexron HP in your transmission. Don't give up on it.

ShamrockShooter · April 30, 2019

I asked my dealer. I have harsh 1-2 shift the first couple shifts in the morning when cold. Gm has a bulletin #16-NA-361 that says its normal due to the initial clutch fill time on the 2-3-4-6-8 c4 clutch. Advise customer it's normal and won't affect reliability or performance. Replacing transmission won't fix it. I have driven 5 19s so far and they all do it to some degree.

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Z45 · April 30, 2019

You are driving a computer so expect anomalies.

Z45 · April 30, 2019

fwiw " The new fluid (19417577) has a new GTL (Gas to Liquid) base stock "

GTL base stocks are Gr. III. There are five groups in the classification system, ranging from Group I – Group V:

Group I Characteristics
Group I base oils are the least refined of all the groups. They are usually a mix of different hydrocarbon chains with little uniformity. While some automotive oils use these oils, they are generally used in less-demanding applications.

• Group II Characteristics
Group II base oils are common in mineral-based motor oils. They have fair-to-good performance in the areas of volatility, oxidation stability, wear prevention and flash/fire point. They have only fair performance in areas such as pour point and cold-crank viscosity.

• Group III Characteristics
Group III base oils consist of reconstructed molecules that offer improved performance in a wide range of areas, as well as good molecular uniformity and stability. Manufacturers can use these synthesized materials in the production of synthetic and semi-synthetic lubricants.

• Group IV Characteristics
Group IV base oils are made from polyalphaolefins (PAO), which are chemically engineered synthesized base oils. PAOs offer excellent stability, molecular uniformity and improved performance.

• Group V Characteristics
Group V base oils are also chemically engineered oils that do not fall into any of the categories previously mentioned. Typical examples of Group V oils are esters, polyglycols and silicone. As with Group IV oils, Group V oils tend to offer performance advantages over Groups I – III. An example of a mineral-based Group V exception is a white oil, a very pure lubricant used in industries ranging from cosmetics to food processing.

Edited April 30, 2019 by elcamino

Darmichar · April 30, 2019

My 2018 spent 2 days at the dealer because of this. I can't recreate it and the techs they send out play dumb and "don't feel it". I can sometimes get mine to do it under ~75% acceleration climbing an incline (think on ramp going up).

Bmwtech113 · April 30, 2019

1 hour ago, Darmichar said:

My 2018 spent 2 days at the dealer because of this. I can't recreate it and the techs they send out play dumb and "don't feel it". I can sometimes get mine to do it under ~75% acceleration climbing an incline (think on ramp going up).

That is when I notice my issue as well, going up an incline with steady throttle.

UGADawgs · April 30, 2019

2 hours ago, ShamrockShooter said:

I asked my dealer. I have harsh 1-2 shift the first couple shifts in the morning when cold. Gm has a bulletin #16-NA-361 that says its normal due to the initial clutch fill time on the 2-3-4-6-8 c4 clutch. Advise customer it's normal and won't affect reliability or performance. Replacing transmission won't fix it. I have driven 5 19s so far and they all do it to some degree.

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I have the same lunge from 1-2nd if it's cold and I lightly accelerate. If I give it half throttle when cold, no issue. Also, no 1-2nd shift issues when warmed up.

ShamrockShooter · April 30, 2019

I have the same lunge from 1-2nd if it's cold and I lightly accelerate. If I give it half throttle when cold, no issue. Also, no 1-2nd shift issues when warmed up.

I have noticed it mostly does it when I back out out of my driveway first then start going forward. This morning it was in the 30s, that first shift from 1 to 2 felt like the transmission slipped. Enough that it actually made my body go forward in the seat a bit like you you were shifting a manual. After that first 1-2 shift of the day it goes back to being normal.

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UGADawgs · April 30, 2019

11 minutes ago, ShamrockShooter said:

I have noticed it mostly does it when I back out out of my driveway first then start going forward. This morning it was in the 30s, that first shift from 1 to 2 felt like the transmission slipped. Enough that it actually made my body go forward in the seat a bit like you you were shifting a manual. After that first 1-2 shift of the day it goes back to being normal.

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Yeah, exactly, but it's 70 here and it does it. But that's cold for an engine.

Edited April 30, 2019 by UGADawgs

ShamrockShooter · April 30, 2019

since I have driven 5 trucks and they all do it, I'm just going to accept it as normal and learn to accelerate harder that first shift of the day

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