8 Speed Transmission

BlancoSilverado · October 3, 2020

29 minutes ago, Jay P said:

The dealer is correct, it came with the updated ATF from the factory. The original fluid was hydroscopic (absorbs water) and the water is what caused all the problems. The newer Mobil 1 fluid doesn't have this issue.

GM is not the only manufacturer to have this issue, Audi had this in the past.

Since you got a used truck with 16k miles on it you don't know how it was driven prior to you taking it home. I would ask the dealer to reset the trans so it forgets all the learning it did prior to you owning the truck. It may cure the issues you are having. If they won't due that or it doesn't change the issue, take the tech or service writer for a ride to show them what your issues are. Much harder to say "no problem found" if you get them to see/feel the issue.

Jay

FYI there has been 3 different fluids that this 8L90 has had over the years. in mid 2019 they switched again to a newer mobil 1 trans fluid.

CamaroVetteGuy · October 3, 2020

50 minutes ago, Kristy F said:

Sorry for the long rant -- We have a '20 Silverado 1500LT (8-spd). Bought it w/16,000 miles on it on Aug 1. Hubby test drove it and I just did the financial stuff. A few days after we bought it, I drove it up to the store and noticed the awful shuddering starting @40mph and especially highway speed. Also, going over any kind of bump or groove in the road, it shakes horribly side-to-side. We had the tires rotated/balanced and an alignment. Didn't help. Took it to 2 dealerships and the first said they noticed a light shudder but no codes came up. Mentioned TSB 16-NA-019 but they didn't have a trans mechanic to work on it and referred us to the other dealership. Just picked it up today from the 2nd dealership. He said they test drove it and there's nothing loose in the suspension and he felt a light shudder but nothing abnormal.

I asked him that when it's time for us to take it in for the regular trans service, if they swap it out with the Mobil 1 - he said that's what is in the truck already (it came with it from the factory). He said they started putting it into the 2019 Trucks from the factory. I call BS but whatever. I looked in the manual and it says it takes Dexron-Hp so I'd assume that's what was put in it in the factory.

I hadn't heard about the 'Chevy shake" until I googled the shuddering. I noticed the comments about the trans fluid, torque convertor, driveshaft, etc. Very disappointed - we were excited about buying our first Chevy truck. That Tundra is looking pretty good right about now.

I guess my question is to take it to a third Chevy dealer and try again and maybe go on the test drive with the mechanic - and demand that they swap the fluid. I'm so pissed off right now but mostly just disappointed.

Kristy F

The Tundra drives and feels like a truck from 2000

Jay P · October 3, 2020

15 minutes ago, BlancoSilverado said:

FYI there has been 3 different fluids that this 8L90 has had over the years. in mid 2019 they switched again to a newer mobil 1 trans fluid.

You are correct, they switched in March of 2019 and the dealer was correct. I have had 2 of these 8 speed trannies. One in a 2015 Silverado and one in a 2019 Colorado. The Silverado had no issues but the Colorado was finally fixed by putting the latest Mobil 1 fluid in it.

Jay

Kristy F · October 3, 2020

Does the Duramax have the shudder?

Jay P · October 3, 2020

1 minute ago, Kristy F said:

Does the Duramax have the shudder?

The diesel doesn't come with the 8 speed trans and the 6 speed and 10 speed don't have the issue.

Jay

Kristy F · October 3, 2020

27 minutes ago, CamaroVetteGuy said:

The Tundra drives and feels like a truck from 2000

Honestly at this point, I don’t care. It’s just exhausting driving our Silverado. Only reason we passed on the Tundar was because of its MPG and towing capacity.
The dealer today did a relearn but the shudder is still there.

SilveradoRST · October 3, 2020

1 hour ago, Jay P said:

You are correct, they switched in March of 2019 and the dealer was correct. I have had 2 of these 8 speed trannies. One in a 2015 Silverado and one in a 2019 Colorado. The Silverado had no issues but the Colorado was finally fixed by putting the latest Mobil 1 fluid in it.

Jay

Any physical damage done on the Colorado tranny shuddering before you finally got the fluid changed? Do you find the 1-2 is better as well afterwards?

Jay P · October 3, 2020

8 minutes ago, SilveradoRST said:

Any physical damage done on the Colorado tranny shuddering before you finally got the fluid changed? Do you find the 1-2 is better as well afterwards?

Bad torque converter and the 1-2 shift was much better. Dealer told me the converter went back GM to see what was going on inside. This was fixed in late Mar of 2019.

Jay

SilveradoRST · October 3, 2020

6 minutes ago, Jay P said:

Bad torque converter and the 1-2 shift was much better. Dealer told me the converter went back GM to see what was going on inside. This was fixed in late Mar of 2019.

Jay

That’s a common thing I read here and there that the torque converter was replaced. Wonder if the bad fluid causes that damage?

If so, maybe I should get the new fluid before I experience the shudder.

Glad to hear the 1-2 improves.

winks79 · October 3, 2020

12 hours ago, BlancoSilverado said:

FYI there has been 3 different fluids that this 8L90 has had over the years. in mid 2019 they switched again to a newer mobil 1 trans fluid.

Yep. I owned a 2018 Sierra with the the 8 speed. No issues, but only put 18k miles on it and traded for a 19' Sierra with 8 speed. Build date was 12/18. Did not have the latest fluid from factory. Around 4-5k miles started having issues. 1-2 shift, shutter, and also a bad delay when shifting from reverse to drive. So bad that is would slam into gear and bark the tires if you did not count to at least five before you put your foot on the gas. Dealer told me had the older tranny fluid and that they would flush and add latest fluid. Cured the problem, now have 20k miles on it and have not had that issue again. My dealer is awesome though. Never had a problem with them. Use the same tech every time I go and have never had a repeat visit for an issue. Most folks I see that have a lot of issues with these trucks do not have a good dealer/tech working on their vehicle to start with, which causes a lot of frustration.

Kristy F · October 3, 2020

2 hours ago, winks79 said:

Yep. I owned a 2018 Sierra with the the 8 speed. No issues, but only put 18k miles on it and traded for a 19' Sierra with 8 speed. Build date was 12/18. Did not have the latest fluid from factory. Around 4-5k miles started having issues. 1-2 shift, shutter, and also a bad delay when shifting from reverse to drive. So bad that is would slam into gear and bark the tires if you did not count to at least five before you put your foot on the gas. Dealer told me had the older tranny fluid and that they would flush and add latest fluid. Cured the problem, now have 20k miles on it and have not had that issue again. My dealer is awesome though. Never had a problem with them. Use the same tech every time I go and have never had a repeat visit for an issue. Most folks I see that have a lot of issues with these trucks do not have a good dealer/tech working on their vehicle to start with, which causes a lot of frustration.

Exactly! I’ve been to 2 dealerships - of course they can’t ‘replicate’ any of it. I could go to a third one or take a drive with the tech but why at this point. I contacted GM - someone will be in touch with me next week.

Edited October 3, 2020 by Kristy F

CamaroVetteGuy · October 3, 2020

4 minutes ago, Kristy F said:

Exactly! I’ve been to 2 dealerships - of course they can’t ‘replicate’ any of it. I contacted GM - someone will be in touch with me next week.

Just keep on them. If they cannot get it fixed they should work out a good deal for you on a new truck or you could potentially go with the lemon law.

And make sure to be polite. You can be firm, but don’t go rude like some people. That makes people not want to help. GM should take care of you. Will likely require some patience which is not easy

Edited October 3, 2020 by CamaroVetteGuy

winks79 · October 3, 2020

6 hours ago, Kristy F said:

Exactly! I’ve been to 2 dealerships - of course they can’t ‘replicate’ any of it. I could go to a third one or take a drive with the tech but why at this point. I contacted GM - someone will be in touch with me next week.

They didn't have to replicate anything. I just told them the issues I was having and they told me about the TSB on the fluid, and that they would take care of it, and they did. They know I'm not going to bring my truck in to have it worked on for no reason. Again, dealership service dept and techs are the issue most of the time when it comes to customers being happy with their vehicle. All vehicle manufacturers have issues, and it makes it worse when service dept. do not and will not fix the issue the first time.

Edited October 3, 2020 by winks79

Kristy F · October 3, 2020

On 10/3/2020 at 2:40 PM, winks79 said:

They didn't have to replicate anything. I just told them the issues I was having and they told me about the TSB on the fluid, and that they would take care of it, and they did. They know I'm not going to bring my truck in to have it worked on for no reason. Again, dealership service dept and techs are the issue most of the time when it comes to customers being happy with their vehicle. All vehicle manufacturers have issues, and it makes it worse when service dept. do not and will not fix the issue the first time.

My stepdad owned a dealership so I was raised and worked in that environment 20+ years. I did everything but sales & loved it! So I’ve been on both sides of the counter. I’m no expert but I’m not stupid.
GM gave me a reference number - they said they’d contact the dealer and myself next week to figure something out.

Edited October 8, 2020 by Kristy F

Kristy F · October 7, 2020

UPDATE: I contacted GM last week - someone reached out to me today. We talked for quite a while. So tomorrow I’m taking it into a dealership not affiliated with the previous two. The GM rep is contacting them to let them know what exactly is going on. I’ll probably drive it with the tech tomorrow so the issues can be ‘replicated’.