Jump to content

1st to 2nd rough shift

BigredGMC
 Share

Recommended Posts

BigredGMC Enthusiast

BigredGMC

Posted
Posted

Hi I have a 2019 GMC Sierra Elevation with the 8 speed, and was wondering if the 1st to 2nd rough shift is normal for this transmission?  Sometimes it shifts without noticing anything and sometimes it slams into 2nd. Been to dealership like 5 times, last time they updated the program so 2nd to 1st rough shift was fixed but still have intermittent 1st to 2nd. Is this normal or should keep going back?  I test drove an 2020 8 speed RAM and that was smooth like butter. Again thanks for replies .

 

  • Like 1
  • Replies 55
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

jlong1984
jlong1984

Mine only has the harsh 1-2 shift when the transmission is cold and I go straight from reverse to drive. If I give it a few seconds before I shift from reverse to drive I don't get a harsh shift. 

vancealot29
vancealot29

I've tried that twice already with two different dealers, this is what I got back....   Hi, Vance. After speaking with your dealer, it has been found that the shift concern you are experienc

UGADawgs
UGADawgs

known issue for cold vehicles. let it warm up first or hold pedal down lightly until in 2nd after initial go.

Posted Images

UGADawgs Enthusiast

UGADawgs

Posted
Posted

known issue for cold vehicles. let it warm up first or hold pedal down lightly until in 2nd after initial go.

  • Like 2
UGADawgs Enthusiast

UGADawgs

Posted
Posted
4 minutes ago, BigredGMC said:

It does it cold or hot. Sometimes worse when feathering the throttle.

Have them change the fluid

  • Like 1
jlong1984 Enthusiast

jlong1984

Posted
Posted
37 minutes ago, BigredGMC said:

It does it cold or hot. Sometimes worse when feathering the throttle.

Mine only has the harsh 1-2 shift when the transmission is cold and I go straight from reverse to drive. If I give it a few seconds before I shift from reverse to drive I don't get a harsh shift. 

 

This seems to be the general consensus among forum members with the 8L90. 

  • Like 3
BigredGMC Enthusiast

BigredGMC

Posted
  • Author
Posted

I guess I f it does no damage, if they do nothing I'll live with it. After highway driving I get the rough shift for about a mile or 2.  When cold it shifts smoothly.  Weird transmission.

bmoney5813 Enthusiast

bmoney5813

Posted
Posted

I had this issue. The thing that consistently worked for me was a deliberate pause after shifting it into gear. Mine only occurred first shift of the day so if yours does it more often it may or may not help. As others have said, the fluid change may be needed. 

  • Like 1
Dunn Senior Enthusiast

Dunn

Posted
Posted

mine had a rough 1st to 2nd if I rushed it......let it warm up and be smooth especially first drive of the day, after that was pretty much smooth as butter.....right before I sold it I noticed a few more clunky shifts that weren't normal but who knows, could have been mental thing....

  • Like 1
topgear1224 Enthusiast

topgear1224

Posted
Posted
It does it cold or hot. Sometimes worse when feathering the throttle.
Known issue / behavior with the 8-speed.

GM has informed dealers and has explicitly stated they are not to change fluid under their customer satisfaction clause. (GM won't pay for it)

The best advice I can give you is find the transmission guy at the dealer.

He can perform a stationary relearn. if that doesn't work he'll likely have to tear the transmission apart and use a micrometer to make sure the clutches are set properly.

At my local dealer here in Alaska the transmission guy (joined GM in 2000) says that every single one that didn't get better with a stationary relearn he had to tear it apart and he found that the tolerances would not correct in the clutch packs from the factory.

I returned my dream truck over the problem.

Went from a 2019 LTZ tech package to a GMC X31 Elevation. Cost me exactly the same amount of money [emoji35][emoji35][emoji35].

Sent from my SM-N975U using Tapatalk

  • Like 1
topgear1224 Enthusiast

topgear1224

Posted
Posted

Might want to try to add your name to the class action lawsuit, it's unlikely you'll get much. But it should at least help with the resale value if they win.

Sent from my SM-N975U using Tapatalk

  • Like 1
BigredGMC Enthusiast

BigredGMC

Posted
  • Author
Posted

Thanks for all the replies. Now for a couple of days while stopped at a red light my engine stumbles and feels like it's about to stall.  It happens about 20 seconds while stopped already.  Does not always do it but has done it twice in 3 days.

topgear1224 Enthusiast

topgear1224

Posted
Posted
Thanks for all the replies. Now for a couple of days while stopped at a red light my engine stumbles and feels like it's about to stall.  It happens about 20 seconds while stopped already.  Does not always do it but has done it twice in 3 days.
It's the stupid transmission tuning. Next time it tries to do it push the brake pedal to the floor. If it stops shuttering it's the transmission tuning.

Do the RPMs drop?

Even on my 10-speed when slowing to a stop and dragging the brake pedal, the transmission is actually fighting the brakes. Every once in awhile it gets so bad that I don't know if I can stop in time. (Feels like it's trying to accelerate)

I just started throwing it into neutral when coming to a stop when it starts behaving badly.

Sent from my SM-N975U using Tapatalk

  • Thanks 1
BigredGMC Enthusiast

BigredGMC

Posted
  • Author
Posted

It stops nicely, no shudder only after about 10-20 seconds it feels as thou it's about to stall.  And yes the RPM's drop during that 10-20 seconds.  It never did it before. I'm afraid to take it up north for the long weekend, don't want to be stranded.

topgear1224 Enthusiast

topgear1224

Posted
Posted
It stops nicely, no shudder only after about 10-20 seconds it feels as thou it's about to stall.  And yes the RPM's drop during that 10-20 seconds.  It never did it before. I'm afraid to take it up north for the long weekend, don't want to be stranded.
How low? And do you have the 2.7 or the 5.3?

Sent from my SM-N975U using Tapatalk

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • PunchT37
      Would this CV Shaft be bad?

      By PunchT37 · Posted

      Yes. You need to check out that thing, and the hub further.
    • anthony2558
      Would this CV Shaft be bad?

      By anthony2558 · Posted

      Would this be normal or a worn CV Shaft? 51K miles 3.5" lift? Boots are intact and no visible leaks showing. Attached is a the video I took. Thanks     https://youtu.be/ZnW7PPRmjJY?feature=shared    
    • Jsdirt
      2010 Avalanche 5.3 not running correctly after engine swap.

      By Jsdirt · Posted

      If everything checks out at the MAF, then the MAF is BAD, new or not.   You don't need a signal generator to troubleshoot this. PCM needs ALL powers and ALL grounds able to light a halogen headlight bulb - if it can light the bulb bright, then the wiring is good enough to run the PCM.   Best thing you can do for yourself is spend some time here: scannerdanner.com - Check out all his YouTube videos on similar issues. If you decide to subscribe it's the best bang-for-buck ratio in the automotive world, hands-down. He's got TONS of free vids on YouTube, too.
    • Tyler Gibbs
      PF63 Oil Filters Going Away?

      By Tyler Gibbs · Posted

      You got that Hengst D110??
    • contrabombarde
      2010 Avalanche 5.3 not running correctly after engine swap.

      By contrabombarde · Posted

      Yes, I used my multimeter to probe all of the wires at the MAF, both with the sensor connected, sensor disconnected, key on engine off, key on engine running, etc etc etc. I probed all of the wires again at the PCM, at the connectors, etc. All voltages are what they should be according to the service manual/wiring diagrams. All grounds are good, less than 20 millivolts from the battery negative under load. Both at the connector of the MAF, at the PCM connector etc.      I know this throws a pretty big wrench into things, but this truck was acting up before the swap. I don't have very much information, if any on what was causing it, but if you cleared all of the dtcs it would do the same thing where it would crank, fire, then die. And it would do the same thing a dozen or so times, and eventually it would start and run, but the difference is that it would run and actually be drivable. Whereas now if you can drive it at all, it goes into reduced power mode almost immediately, and even then it's not running correctly. When you come to a stop at a light it stumbles down to for 500 RPM before catching itself and returning to the smooth idle. And if you go more than about 50% throttle then it immediately goes back to doing the misfire thing.    Like I said, I know that throws a wrench into things, and unfortunately I was not able to pull any data or anything like that before I did this work, so I don't have much to go on.    I'm trying to not fixate on one particular thing as the cause of the problem, but it seems like all avenues are pointing me towards the PCM. Like I said I have tested the wiring extensively (see above), and during cranking the sensor does produce seemingly legitimate values at least according to my multimeter, but as soon as the engine fires those values quickly descend into gibberish. I've tried it with multiple different known working sensors, I have done literally every test I can think of multiple times on the wiring (probing the signals, probing the pins with the sensors unplugged, probing the pins at the PCM, voltage drop, voltage drop under load, continuity, ohms, and double-checking everything against the wiring diagrams/ proper values in the service data.)    Another thing that pushes me towards a possible PCM failure is, I have noticed in troubleshooting a little bit taking a break and coming back, that when I leave the truck to sit for a while and cool off, it starts and runs smoothly when I first start it up. However once it warms up. It starts having problems. For example, when I went out to the truck this morning after it had been sitting overnight, I was actually able to drive it down the block. And then once I got on the throttle a Little bit after going about a thousand ft, it started misfiring again. I pulled it back into the driveway, shut it down, and started it back up. It idled smoothly. As soon as I touched the throttle it did the misfire thing again. From then on as soon as I started it it would misfire. I shut the truck off and went to go get a coffee and do a bit more research. When I came back out I started the truck up and it immediately went into the smooth idle. After a couple of minutes of playing around with it, it would not idle smoothly anymore. Let it sit a couple of hours, rinse and repeat. This makes me think with temperature change something is going wrong inside the PCM. I have the PCM out of the 2007 donor vehicle and I'm thinking of getting a one-day subscription to the ACDelco programming service to try and program that and see if it helps.   Like I said, I'm really trying to not fixate myself on one potential cause, but it seems everything is pointing me towards PCM failure. I would really like to try to confirm that, but unfortunately I don't have an oscilloscope or a signal generator to do the GM service procedure where you feed 5 khz into the signal pin. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...