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Posted

Hello guys, 

 

First time posting here so I apologize if I didn't post in the right section. Currently drive a 2018 silverado hybrid with eassist. 

 

Currently been experiencing some problems with braking. Whenever I brake it jerks before I come to a complete stop. Ran it by the mechanic at chevy and they told me it's because the "brakes are cold" afterwards it started becoming a little more often so I took it in again and they said everything was fine again. 

 

Starting to run out of options and patience to be frank with y'all. Is anyone out there with the same model experiencing the same issue or have any advice to get it fixed. I'm starting to lean towards the idea of trading it in biting the bullet and getting a Z71. 

Posted

It's not the brakes.  It is the crappy 8 speed transmission.  Mine does the same thing.  I was recently stuck in stop and go heavy traffic.  The transmission jerked when I took off and jerked when slowing down.  If you don't come to a complete stop and slowly accelerate, it can slam my head into the headrest.  Unfortunately, there is nothing your (or I) can do about it.

  • Thanks 1
Posted
41 minutes ago, steepllama said:

Hello guys, 

 

First time posting here so I apologize if I didn't post in the right section. Currently drive a 2018 silverado hybrid with eassist. 

 

Currently been experiencing some problems with braking. Whenever I brake it jerks before I come to a complete stop. Ran it by the mechanic at chevy and they told me it's because the "brakes are cold" afterwards it started becoming a little more often so I took it in again and they said everything was fine again. 

 

Starting to run out of options and patience to be frank with y'all. Is anyone out there with the same model experiencing the same issue or have any advice to get it fixed. I'm starting to lean towards the idea of trading it in biting the bullet and getting a Z71. 

Welcome to the site. Like the prior post said, it is the transmission. How many miles do you have on the truck? The transmission does have a period of "learning" where it tries to figure out your driving habits, which could be happening, or maybe you just have one needs some attention.

  • Thanks 1
Posted

Right now it has 15,300 so it hasn't been run hard. I'll probably take it to get the transmission looked at. Is this an issue with all Chevy trucks? Might just sell it back and get a different vehicle. 

Posted
6 minutes ago, steepllama said:

Right now it has 15,300 so it hasn't been run hard. I'll probably take it to get the transmission looked at. Is this an issue with all Chevy trucks? Might just sell it back and get a different vehicle. 

Yes and no, to answer the question about the transmission. If you like the truck otherwise, I would not give up just because of this issue. In my personal experience with GM's warranty is that they will take care of you, it may take some time, but they will make you happy.

  • Thanks 1
Posted

The Ford/GM 10 speed trans is a much better transmission.  I have had my 2017 Yukon Denali in to a very good dealer twice.  They found an obscure computer program and reflashed the computer.  It had to go through a whole new learning period.  As time went on I'm right back to where I was before.  There are times when I make a slow left turn without stopping and slowly accelerate up a short street that has a steep incline.  As I feather the throttle up the hill, it slams into first gear so hard our heads hit the headrest.  Once, while driving in a busy parking lot, as traffic started moving, the trans shifted unexpectedly into 2nd causing the truck to lurch forward.  I could have easily hit the car ahead if I didn't hit the brakes quickly.  Also, I often drive on a highway with a 55mph limit and several signal lights.  When a signal far ahead turns red I slowly decelerate.  As I get to the light the trans drops harshly into first causing me to let off the brake and making the stop real sloppy.

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Posted (edited)

Get up to highway speed and  Shift into  neutral when safe to do so and start applying the bakes, and if it still does the pulsation its in the brakes.

Edited by mjm-1957
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Posted

Definitely not going to give up on the truck just yet, it's just frustrating. I'm going to call the dealership and see what we can do. 

 

Yeah, all those problems you just mentioned is exactly what is happening with my truck. Makes driving sometimes very painful. What about a tuner? Do y'all have any experience with that? I heard that in the last models people were putting tuners in their trucks and that solved that gear shift process. 

Posted (edited)

Something that needs to be aware of is that when truck is in drive, 1st gear has zero engine braking.  This means that when you are coasting to a "near stop", then pressing the accelerator, if the transmission zzhas alreadyz shifted into low gear, the engine will instantly increase in rpm's to catch up to your speed . 

 

Manual ow gear(when you manually select low or 1st gear} will give you engine braking.  I don't know how it works in GM transmissions, but in the old style torqueflyte transmissions, when shifted to low gear it would apply the low/reverse band to enable engine braking.  Otherwise the overrunning(or one way) clutch would just freewheel.  Back in those days I would just adjust the governor mounted on the output shaft by changing a small spring.  Could do that without removing entire transmission, just needed to slide the extension housing back about 4 inches. 

 

The easiest way to see this is to put the truck in manual low gear before you get to the corner, or to the thing that normally made the issue you are having. If the issue goes away, then the transmission is downshifting into automatic low and behaving correctly. Or you could make yourself aware of the situation and alter your driving habits.

 

This never happened prior to current technology because current technology has removed engine braking in most gears to help emissions and improve fuel economy.  I don't know if this is something that can be tuned better or not, but GM should be aware of it happening.  Maybe if more people complained more about it, GM may look into a simple minor adjustment to the firmware to better handle how it downshifts into low gear. 

Edited by Doug_Scott
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Posted

That certainly is not my experience.  When gradually braking for a red light it does slow down significantly when downshifting to the point I have to lift way off the brake and creates an uncomfortable ride.  Also, when I manually shifted to the lowest gear in heavy stop and go traffic, it would not shift and stay in first gear.  Second gear is as low as it will go.  The harsh upshift and downshift continued.

Posted

And people wonder why GM is failing yet again ...

 

I'd get into the habit of throwing the thing in neutral when slowing down in city traffic, and just do brake jobs more often than normal. Will probably wear out the shifter, too, the way they build these things today ... :sigh:  Can't win!

  • 10 months later...
  • 1 year later...
Posted
On 1/19/2019 at 10:48 PM, steepllama said:

Hello guys, 

 

First time posting here so I apologize if I didn't post in the right section. Currently drive a 2018 silverado hybrid with eassist. 

 

Currently been experiencing some problems with braking. Whenever I brake it jerks before I come to a complete stop. Ran it by the mechanic at chevy and they told me it's because the "brakes are cold" afterwards it started becoming a little more often so I took it in again and they said everything was fine again. 

 

Starting to run out of options and patience to be frank with y'all. Is anyone out there with the same model experiencing the same issue or have any advice to get it fixed. I'm starting to lean towards the idea of trading it in biting the bullet and getting a Z71. 

Same experience with the 2017.  8 speed transmission is terrible.  I had it replaced with new because of the issues with it but it did not resolve the problem.  New is no better.  1st and 2nd gear up and back.  When coming to a stop, slowly, the truck will lurch forward.  It feels as if the brakes are stopping the truck but they are, it is just that the transmission is a pos.  GMC know that this is an issue and I see it as a safety issue.  DOT should be involved.  Not sure if the 10 spd is any different.  Just 25K miles on my odometer.. been a problem since 10K.

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