Those with 8 speed shudder problems?

samckitt · March 5, 2019

Have been fighting a shudder with this truck, it has 15k miles on it & has been in the shop a few times for it (still under warranty). What I feel, almost feels like a miss fire, but no check engine light. When driving at constant speed, occasionally I will feel something, like a random miss fire, and when slightly accelerating I feel it alot, 10-12 times a second. Trans fluid was changed, nothing, changed torque converter, nothing, had it in last week for oil change & they changed the trans fluid again, said there was a new fluid out. For about 200 miles it felt different/better, (actually smiled driving it) it shifted when I felt it should, & didnt notice the shuddering. Now today on my way to work, it felt like it was back to the way it was before the last fluid change.

Stitches040 · August 14, 2019

Any updates on anyone with the prior fix. Did the flush work?

I have a 2018 Denali 6.2 / 8 .... Only 6500 miles on it, and it has started the shudder. I traded in a 2015 SLT/All Terrain 6.2/8 that had developed the same condition.

Gagliano7 · August 14, 2019

On 3/5/2019 at 10:34 AM, samckitt said:

Have been fighting a shudder with this truck, it has 15k miles on it & has been in the shop a few times for it (still under warranty). What I feel, almost feels like a miss fire, but no check engine light. When driving at constant speed, occasionally I will feel something, like a random miss fire, and when slightly accelerating I feel it alot, 10-12 times a second. Trans fluid was changed, nothing, changed torque converter, nothing, had it in last week for oil change & they changed the trans fluid again, said there was a new fluid out. For about 200 miles it felt different/better, (actually smiled driving it) it shifted when I felt it should, & didnt notice the shuddering. Now today on my way to work, it felt like it was back to the way it was before the last fluid change.

Is going into afm when you feel the shudder?

Ron_Swanson · August 14, 2019

So is this shudder problem covered by warranty? I bought a used 2016 5.3 with the 8 speed months ago. I’m coming up on an oil change and was going to have them change the tranny fluid as well when I found this thread. I have a lot of these issues, mostly at low speed. Bought a full bumper to bumper warranty for it so just curious. 49k on the odo.

elcamino · August 14, 2019

Good ole low bidder factory fill atf is the problem

Fluid Exchange

The TCC shudder condition is related to moisture content in the transmission fluid. The current fluid tends to be hydroscopic, or absorbs moisture, which increases the chance of TCC shudder. There are three different fluid exchange procedures to follow, depending on vehicle application, so that an acceptable concentration of the new HP fluid is achieved in the transmission.

The new Mobil 1 Synthetic LV ATF HP transmission fluid is now available to U.S. dealerships through your local GM Oil Distributor. The new Mobil 1 Synthetic LV ATF HP transmission fluid is available in quart bottles (GM Part Number 19417577) and, for a limited time, in 55-gallon drums (GM Part Number 19417904) (Fig. 12) in most locations. Drum production ended in January 2019. The GM part numbers are not on the product. The Mobil 1 Synthetic LV ATF HP fluid and the required tool kit will be available to all Canadian dealerships by the end of March 2019. GM Part Numbers for 0.946 liter bottles will be provided at that time.

samckitt · August 14, 2019

5 hours ago, Gagliano7 said:

Is going into afm when you feel the shudder?

No. Had service tech ride with me, he felt it & had it in the shop, said it was not the transmission, put a different tune in for engine & its better, but still feel it occasionally.

Crstfr · August 14, 2019

this will come back... had the fluids replaced and tpm re flashed at 30k.. i'm at 60 and it does it like it first did... sucks.. but i just deal with it... seems to happen more on going down small hills, shifting from 1st to 2nd.

samckitt · September 18, 2019

On 8/14/2019 at 3:36 AM, Gagliano7 said:

Is going into afm when you feel the shudder?

No.

High Country 6.2L/8 · September 21, 2019

On 4/6/2018 at 8:46 PM, DTB said:

I think my 16 Sierra 5.3/8 speed might be experiencing it. Seems to happen mostly around 45-50 under light throttle while cruising. It definitely has the rumble strip feel. It happens maybe two times for a second or two each and then it seems to go away. Also, the tachometer seems to flutter a lot, whether it is shuddering or not. Is this the symptoms that call for a torque converter or flush? I’m within 500 miles of the 3yr/36 so I want to hopefully get this resolved soon. I’m suppose to take it to the local Chevy dealer where my cousin works who is a transmission man. He is going to try to diagnose it although they said I really need to take it to the local GMC dealer (that I don’t like) for the warranty work? I figured GM was GM as far as that type of work went.

You mean 6 speed? Is the issue fixed

ToddTuttle · September 26, 2019

Just purchased a used 2018 GMC Sierra 6.2L 8-speed with 21k miles, single owner. Started experiencing the shudder issues described here within the first week. Found the GM Teck-Link article which references this dated 01/2019. Called my local dealership and described what I was feeling and the research I had found. Was told by them they had seen several from 2014-2018, 8 speed only and they had tried many things but GM had the fix (as of 01/2019) and he referenced the same GM Tech-Link article I was looking at (https://gm-techlink.com/?p=11127). The dealership says 95%-98% of these issues are fixed with the fluid exchange; specifically Mobil 1 Synthetic LV ATF HP and it was covered under warranty if less than 36,000 miles.

Had this done today, confirmed they used part number 19417577 fluid per their invoice. Have only driven it home so outcome is yet to be determined. Currently pleased with GM handling of the issue.

ToddTuttle · September 29, 2019

On 9/25/2019 at 8:26 PM, ToddTuttle said:

Just purchased a used 2018 GMC Sierra 6.2L 8-speed with 21k miles, single owner. Started experiencing the shudder issues described here within the first week. Found the GM Teck-Link article which references this dated 01/2019. Called my local dealership and described what I was feeling and the research I had found. Was told by them they had seen several from 2014-2018, 8 speed only and they had tried many things but GM had the fix (as of 01/2019) and he referenced the same GM Tech-Link article I was looking at (https://gm-techlink.com/?p=11127). The dealership says 95%-98% of these issues are fixed with the fluid exchange; specifically Mobil 1 Synthetic LV ATF HP and it was covered under warranty if less than 36,000 miles.

Had this done today, confirmed they used part number 19417577 fluid per their invoice. Have only driven it home so outcome is yet to be determined. Currently pleased with GM handling of the issue.

UPDATE: Just drove this truck over 300 miles over the last three days. No sign of the shudder. Transmission is smooth and feels strong. Still have the hard transfer from 1st to 2nd and 2nd to 3rd when cold and first taking off. I have read other threads about this as well, it disappears once the engine/transmission is warm.

Bikemobile · September 30, 2019

On 3/1/2019 at 3:52 PM, Jdub289f said:

Anybody else have further issues on this? I have a 2018 1500 5.3l 8-speed. I have never had the higher speed shutter (50-60 mph), but more of a jerking motion when the truck is almost coming to a stop but barely rolling forward. It also tends to have a solid clunk even when lightly applying the throttle after coasting for a few seconds at city speeds. I got the newest full syntheic ATF put in a couple weeks ago, and no change. I have the E-assist model (which I'm annoyed by the start/stop feature), but not sure if that changes anything. Has anybody had similar behavior? Maybe had the torque converter replaced? Maybe a 2019 transmission or torque converter installed being that they redesigned it for 2019? Taking it into the dealer again next week and they are going to try and diagnose further and compare it to other trucks. My dealer in Watsonville, CA has actually been working with me very well on this issue. Any input?

I have the same low speed clunks and bumps. Any progress on this?

jbsilverado · September 30, 2019

Just bought a CPO 17 Silverado LTZ 6.2 w/ 8 speed last week and instantly noticed it on my way home as I knew it wasn’t normal. Took to the threads and found similar issues so I feel better now. I called my local dealership (not the one I bought it from because they are 120 miles away) and described the issue to them and the service rep instantly knew what I was talking about and explained what was going on. As per the rep I talked to, the torque converter was the overall cause of the shutter. Something to do with the original oil they used in the tranny. The truck has 44K on it and being certified pre owned I got an extra year/12k bumper to bumper so I should be covered. He advised that the service bulletin says to flush it and reprogram it so it can relearn, he then said if that doesn’t fix the issue (after 5 days/500miles) to bring it back and they will do what’s next and totally replace the torque converter. That solved the shutter at certain rpm but what about the had shifting from 1st to 2nd and vice versa? Well his answer to me was and I quote “As for the harsh shifting, you may never totally get all of that out. That’s just how that transmission is, being stacked with 8 gears”. So my appointment is Thursday, and they were nice enough to supply a loaner. I will update with results.

Edited September 30, 2019 by jbsilverado

Fabricator19 · October 2, 2019

These forums have been very helpful through all of this. So wanted to repay the favor in what I have found/dealt with. I have a 16’ Sierra with around 77k on it. I’m the second owner bought certified preowned. I noticed the shudder right away but thought I was crazy. Well over the last 4 months it had gotten so bad others in the truck noticed it. Took it to the dealer and they couldn’t replicate. (Of course) so I drove it some more to the point it did it all the time. This time different dealer recognized the problem. Spoke to a very knowledgeable tech who knew right away and was well versed in the fix. Anyhow fast forward dropped it off Monday and received the truck back today. They did the flush under warranty (dodged $600 bullet) I’ve only driven it home so time well tell. The tech did say because of the mileage he wouldn’t be surprised if it came back for a torque converter swap. He assumes damage. But out of the 12 he’s done none have come back yet. So fingers crossed. I

attached the service slip as a reference.

Edited October 2, 2019 by Fabricator19

jbsilverado · October 2, 2019

14 hours ago, Fabricator19 said:

These forums have been very helpful through all of this. So wanted to repay the favor in what I have found/dealt with. I have a 16’ Sierra with around 77k on it. I’m the second owner bought certified preowned. I noticed the shudder right away but thought I was crazy. Well over the last 4 months it had gotten so bad others in the truck noticed it. Took it to the dealer and they couldn’t replicate. (Of course) so I drove it some more to the point it did it all the time. This time different dealer recognized the problem. Spoke to a very knowledgeable tech who knew right away and was well versed in the fix. Anyhow fast forward dropped it off Monday and received the truck back today. They did the flush under warranty (dodged $600 bullet) I’ve only driven it home so time well tell. The tech did say because of the mileage he wouldn’t be surprised if it came back for a torque converter swap. He assumes damage. But out of the 12 he’s done none have come back yet. So fingers crossed. I

attached the service slip as a reference.

That’s exactly what I was thinking about the mileage on mine. I can see how a flush would help with a vehicle with lower miles, but after a certain point you would just have to assume the torque converter would be damaged and have to be replaced. Which is why I’m thinking that even if the flush does stop the shutter, I’m tempted to take it back within the next two weeks requesting for it to be replaced. Because if it does return, it would probably come back the day after the warranty expires and I would have to pay out of pocket for the service.