GM 8-Speed Transmission Lawsuit Heats Up - Does Yours Shudder?

OldChevyNut · May 13, 2019

As a comment for Mr. Rutherford's persistent vibration problem, the vehicle should be capable of reaching the computer-controlled maximum-allowed speed of about 125 mph without noticeable vibration. Just think, cop vehicles do it all the time, but their speed limiter is usually set for 140 mph or higher.

Vibration such as you describe is generally caused by a rotating mass. Objects with a small diameter usually develop less vibration than objects of a large diameter, so when trying to find out what causes a given problem, start with checking things with large diameters. In the transmission area, the object having the largest diameter is the torque converter.

But then again, the transmission may not be the only source of excessive vibration. In most cases that I'm aware of, tires and suspension components are the most common causes of high vibration levels.

Virtually every dealer can check vibration levels by attaching sensors at specific points on a vehicle, then using a fairly common device that picks-up the sensor readings under a road test and displays results by the frequency (in Hz) and intensity of the vibration. Then the tech looks into a book, finds what can cause vibration at the noted frequency, and then further work is directed at the suspected vibration source. At least, that's how it's supposed to work, and it can be a laborious and costly process of testing, fixing, retesting.

The dealer(s) should have started by testing the vehicle as above, then simply fixing the vibration sources and retesting until all vibration levels are withing factory levels.

But by your comment, this didn't happen. So you're probably getting a dealer doing some amount of work with tires, driveshafts, etc, without doing any testing and having no idea what the real problem is.

And when they think they've done enough, you'll get statements like "normal vibration" simply because the dealer doesn't want to spend the time and money to fix it.

Under such conditions, the best advice I can give is to continue taking the vehicle to the dealer, or a different dealer, documenting the condition and the vehicle mileage when the issue was first reported for warranty purposes, then insist the dealer test and repair the problem and even put "normal vibration" statements in WRITING. Do this many times, keeping all records associated with each dealer visit, and after many attempts to correct the condition, if problems persist, file for resolution via "lemon law" mechanisms such as arbitration or even litigation.

But I wouldn't continue to drive any vehicle with such an obvious defect. I would insist they either fix it or buy it back.

But then again, that's just me.

Hillwood · May 13, 2019

Make sure GM customer care is always involved with your concerns.. The dealer is not going to do anything that GM won't pay for.. Getting payment for warranty repairs is not automatic..

The dealership is a business just like any other.. Maximizing profits and minimizing costs..

If GM won't pay for the repairs then it comes out of the dealer profits..

Always get the General involved because the General pays for the repairs not the dealer.

OldChevyNut · May 14, 2019

I agree with Hillwood's statement 100%

Snuff · May 17, 2019

So what is a man to do? I was about to order a 2019 RST Crew 5.3 with 8 speed.

Then I read that the 2020 is coming soon. I read an article from Donlen that said you can order 2020 (now or soon) for Production in August. Now I am reading all the complaints and about the 8 speed lawsuit.

Do we think the 2020 8 speed (MQ3) will be better? I can not afford the 6.2 and 10 speed.

Dont really want to look at F150 because they are having issues with their 10 speed.

Which truck to buy?

Edited May 17, 2019 by Snuff

Paintor · May 18, 2019

6 hours ago, Snuff said:

Which truck to buy?

Go to Youtube and search for “6.6 Duramax Ute”

Those Australians shoving new 6.6L diesels into Japanese trucks are onto something.

OldChevyNut · May 18, 2019

For Snuff: I no longer own a GM vehicle, and currently own a Ford F-150 XLT Crew 5.0 10-speed plus the usual goodies. I have no problems of any sort with the vehicle (except for keeping it clean), but have just over 1100 miles on it.

Because I received a notification regarding this post, today I spoke with 2 of my former colleagues at the GM Transmission plant in Romulus, Michigan (where I was employed prior to retirement). From what I've been told, GM engineers keep track of Ford-reported issues because the GM 10 speed unit is functionally nearly identical. Ford has reported low-occurrence issues with rough shifting and "gear searching" in less than 2% of vehicles with 10 speed transmissions returned for service. I've been told both issues have been resolved, with a single TSB issued for the rough shifting issue. Like the GM 8 speed, the Ford 10 speed is an adaptive unit, where the user driving habits are recorded and used when the same user operates the vehicle, and Ford finds that when the vehicles have been driven for approximately 800 miles or more, the occurrence of owner-reported "gear searching" issues is virtually eliminated.

Because I know the Ford 10 speed has been getting very positive results from using the 10 speed in F-150 and Ranger vehicles, and that I did considerable research into history of the unit prior to my recent purchase, I would recommend it without reservation.

I cannot say the same for any previously existing version of the GM 8 speed unit.

However, I was told the NEW GM 8 speed transmission, earmarked for use in Silverado 2500 vehicles, is a new design, not just a warmed-over version of the 8L90.

I'm also told the new Allison 10 speed unit earmarked for Silverado 3500 vehicles is testing to be far superior to the existing 8L90 8 speed or even the GM 10 speed.

And I was told that certain 2020 GMC Sierra 1500 models will offer the GM 10 speed as an option, even on 5.3 liter engines but not with 2-wheel drive. I was not told if a similar option would appear for the 2020 Chevrolet version.

I'm not sure if any of the above helps with your 2019 decision, but it's about all I could find out on short notice.

But if it were me, and I needed a truck now, it would be the Ford.

If I could wait 4-5 months, I'd check-out the 2020 GMC Sierra with a 10 speed option.

I would not buy a GM 2019 with an 8 speed under any circumstance.

BTW, here's a couple of the news release links I found that back-up the info I was given on the 2020 GMC Sierra 1500.

https://www.cnet.com/roadshow/news/2020-gmc-sierra-1500-technology-powertrain-updates/

https://media.gmc.com/media/us/en/gmc/home.detail.html/content/Pages/news/us/en/2019/may/0517-gmc.html

Snuff · May 18, 2019

Thanks Mate!

Mandalorian · May 18, 2019

20 hours ago, Snuff said:

So what is a man to do? I was about to order a 2019 RST Crew 5.3 with 8 speed.

Then I read that the 2020 is coming soon. I read an article from Donlen that said you can order 2020 (now or soon) for Production in August. Now I am reading all the complaints and about the 8 speed lawsuit.

Do we think the 2020 8 speed (MQ3) will be better? I can not afford the 6.2 and 10 speed.

Dont really want to look at F150 because they are having issues with their 10 speed.

Which truck to buy?

Ram has the pretty perfect ZF 8-speed. It's hard to beat the Hemi/ZF8 combo.

OldChevyNut · May 19, 2019

5.7 or 6.4 Hemi with a ZF 8 (8F70/8F75) is a great package. Basically a 6 speed unit with 7th and 8th being OD for highway use. High first gear ratio is good for hauling/towing, which is what a truck is for, right ?? But real-world mpg numbers in the 13 range, high MSRP's in the 60K-85K range, and marginal/poor dealer services make buying one a chancy proposition. After renting a well-equipped Laramie 5.7 for 4 days to do a real test drive, I didn't buy.

worldaccordingtojim · May 20, 2019

I had a 16 5.3 8 speed, it was the worst driving transmission I ever owned. It hard shifted randomly when slowing down, it hesitated all the time, I never felt like I had power. It was so bad passengers even commented. There were times I would press the gas and it was like ti had to think about what to do. I came from a 2010 GMC Sierra 5.3 6 speed that ran like a dream. After a few service sessions with no issues found, I decided to trade up for a 2019 5.3 6 speed. I can tell you after a month, going right from the 5.3 8 speed to the 5.3 6 speed it is night and day. Driving and towing it feels like a I doubled the power, but really it is the same engine. Zero hesitation, hard shifts, and it always seems to have power on had. Honestly the whole thing that it has to learn to shift correct is bullshit.

Edited May 20, 2019 by worldaccordingtojim
Grammer

econometrics · May 20, 2019

8 minutes ago, worldaccordingtojim said:

Honestly the whole thing that it has to learn to shift correct is bullshit.

Maybe. But I can say that my 2019 8 speed has improved significantly as I've owned the truck over the first 2000 miles.

wizard4878 · May 20, 2019

well, knock on wood, I haven't had any of these problems with my 8 speed, in fact it's so smooth I have a hard time telling when it actually shifts. Maybe I'm just lucky (not likely), because I heard/read all sorts of problems with the 4L60E trans also, but never had a problem with that one either. It went 186,000+ miles over 14 years

econometrics · May 20, 2019

8 minutes ago, wizard4878 said:

well, knock on wood, I haven't had any of these problems with my 8 speed, in fact it's so smooth I have a hard time telling when it actually shifts. Maybe I'm just lucky (not likely), because I heard/read all sorts of problems with the 4L60E trans also, but never had a problem with that one either. It went 186,000+ miles over 14 years

Yeah, my 4L65E in my 2007 LTCC RWD was an amazing transmission. Never once had any issues with around 125K on it (before I traded it late March 2019 for a T1).

OldChevyNut · May 20, 2019

For wizard4878, Glad to hear your vehicle is doing good, and I wish you the best of luck in the future. Actually, ALL TSB's on 8L45 and 8L90 have been cancelled. The 6 speed was much more likely to shudder, usually going from 2nd to 3rd and having problems selecting which gear. The 8 speed had a similar problem, plus others. But since the introduction of some "better-late-than-never" product changes, proper diagnostic test equipment distributed to every dealer, and the still-continuing re-formulation of a suitable transmission fluid, vehicles manufactured after 2-16-19 and equipped with a 8L45 or 8L90 are SUPPOSED to be trouble-free. Too bad mine wasn't, but it's gone now (buy back following litigation) so I shouldn't speak badly of the dead. By the way, the 4L60E was fairly reliable, but the 4T60(E) was a major reliability nightmare for GM.

OldChevyNut · May 20, 2019

For worldaccordingtojim, I disagree about how you regard the transmission "learning". It's actually referred to an "Adaptive" transmission, it's been around for a couple of decades, and it's not alone. Ford 8 speed and 10 speed have the same feature, as does the new GM Allison 10 speed and the 8 speed ZF 8 used in many Ram products and European vehicles.

In 2019 GM vehicles, I'd highly recommend you setup your operator profile and assign it to a key fob ID, so the vehicle can begin learning how you operate the vehicle.

From the time you establish the profile, your driving habits will be recorded and used for altering transmission characteristics during vehicle use, such as shift points.

If a second person operates the vehicle, that person should also create their own profile and assign the other key fob ID.

If more than 2 persons operate the vehicle, the 3rd (and any other operators) may also need to create profiles and assign a specific key fob ID, otherwise, as they operate the vehicle the way they want, that data may indeed corrupt the profiles of operator 1 or 2.

If you don't establish a profile, the factory default settings are used from the moment the vehicle was taken out of "Transport" mode during dealer prep.

By the way, the operator profiles save a lot more data than just usage information, like all of the available entertainment (AM, FM, Syrius) and communication (Apple, Blue Tooth, etc) preferences. So once you understand what it can provide, the operator profile can be a very desirable feature.