[Old Tom]

Being the new guy here I'd like to contribute something useful. I think it's been covered before but maybe I can add something new.


My 2017 SS with 6800 miles developed a shudder at all speeds. I thought at first it was the road but it happened on the smoothest surfaces. It felt like driving over rumble strips, never more than a few seconds, but definitely indicating a problem. I took it in to the dealer, and after 2 days they diagnosed it as a faulty torque convertor. The shudder was the convertor locking and unlocking, shuddering the whole car.


The said the cure was to flush the convertor 3 times and give it back. The service manager told me Chevy wants it driven 200 miles to see if the problem returns. If not, ok, but if it does they will replace the convertor. They couldn't tell me what causes the shudder, but it seems to be a common problem on the 2016-17 six and eight speeds. It's surprising that no TSB has been issued but the manager told me it it starts get to the dealer pronto because it will eventually take out the transmission. I've got about 100 miles on the "fix" and I'm just waiting for the other shoe to fall.

[arpad_m]

Unfortunately, this is an expansive issue with 2016 and 2017 models, I recall some have seen it even on 2018's. There is a section on this site dedicated to Q&A with the Camaro chief designer, Al Oppenheiser, and he provided a response to this specific question about the 8-speed automatic transmission (A8), see https://www.camaro6.com/forums/showthread.php?t=527133.

In addition to the thread above, you'll find many other if you just search for "shudder". I am not an expert, but the overall consensus seems to be that neither the flush nor the torque converter replacement is an ultimate solution, as the problem may return even after the latter, and the transmission needs to be tuned to fix the problem in the long run. Obviously, tuning means kissing the GM powertrain warranty goodbye.

[KingLT1]

yep.. unless you are willing to tune the transmission so the converter quits slipping at cruising speeds, you might as well part with the car. GM needs sued over this because the Ultimate fix requires voiding the warranty and their fix is band-aiding the issue until your warranty is up.

[ItsChristianInHD]

Originally Posted by arpad_m

Unfortunately, this is an expansive issue with 2016 and 2017 models, I recall some have seen it even on 2018's. There is a section on this site dedicated to Q&A with the Camaro chief designer, Al Oppenheiser, and he provided a response to this specific question about the 8-speed automatic transmission (A8), see https://www.camaro6.com/forums/showthread.php?t=527133.

In addition to the thread above, you'll find many other if you just search for "shudder". I am not an expert, but the overall consensus seems to be that neither the flush nor the torque converter replacement is an ultimate solution, as the problem may return even after the latter, and the transmission needs to be tuned to fix the problem in the long run. Obviously, tuning means kissing the GM powertrain warranty goodbye.

Does yours shudder in V4?

[Old Tom]

Originally Posted by ItsChristianInHD

Does yours shudder in V4?

I wouldn't testify to it but I think it was V4 because I was just rolling on level ground, maintaining steady speed, and the rumbling started. Truefully I can't say yes or no but the conditions say I was V4. How does this affect the problem?

[crosive]

Originally Posted by Old Tom

I wouldn't testify to it but I think it was V4 because I was just rolling on level ground, maintaining steady speed, and the rumbling started. Truefully I can't say yes or no but the conditions say I was V4. How does this affect the problem?

the tc is set to allow more slip in v4 mode to alleviate the pulsing from the engine. Whenever mine had the shudder, v4 mode was wayy worse than in v8 mode.

[KMPrenger]

Yep. Someone within GM (more like multiple someones) knows this is a huge mess up but the cost to correct it all would likely be absolutely huge. Of course, GM has already had to have spend tons of money on the warranty repairs on this one, but that's what they will do until people's warranties run out and they can get the 10 speed out into the market.

This issue affects multiple brands, cars, and trucks over a multi-year span...I hate to say it, but it really does deserve special attention, whether that be through some kind of class action suite, or just GM at least having the decency to give an extended warranty on the TC and transmission.

If this issue still continues into the 2019 trucks with the 8 speeds I'll be shocked....how GM can continue to just let this go on without at least working in a fix at some point is disappointing at best....but so far its been an issue for at least 3 - 4 model years worth of vehicles.

[crosive]

It is a problem, I'm not downplaying it. they've already thrown a blanket statement trying to say they know what the problem is, and fixes for it (look in the ask al section). However, that isn't the only problem (my car should have come with the correct fluid from the factory, according to build date. It has been flushed with the correct fluid twice, still not fixing the issue).

so, to fix the problem, they would have to remove v4 mode, replace your fluid with the correct fluid if it hasn't been already, and zero out your slip tables. If your tc is not malfunctioning, that should fix the issue. This however changes quite a few things, notably fuel mileage that gm has already taken into account.

just using this as one example, I don't have to explain to you how much trouble they would be in if they released a car deserving of the gas guzzler tax, with an option that bypasses said tax, then removes said option because of a "oops" on their part.

They are handling it as professionally as they are allowed to. Gm itself wants your car functioning with no issues. Individual dealers are the problem most of the time.

[Kaji]

How big of an issue is the shudder with the 2018's?

[Herewego]

Originally Posted by Kaji

How big of an issue is the shudder with the 2018's?

If you look in the technical section under transmissions, I think you may find one or two examples. I don’t know if they’ve been verified but they seem to be few and far between.

[arpad_m]

FWIW the A8 in my 2018 2SS is still flawless after 2000 miles. Had a preventive flush done by the dealer at 1500 mi (very-very helpful service manager there).

I know it's still very early to call at such a low mileage, just wanted to add a data point. Also, I am planning to take the tuning approach sooner than later, this car needs to serve me for the long haul. (The '19 SS has a front even a mother would have a hard time loving, me not like the rear goggles either, power is the same, RVM and MyLink 3 alone aren't worth it, so trading in or up is not an option.)

[avalonandl]

The real fix is swap to an M6 car.......

[JACKPAC]

They flushed my system and told me the problem wasn't solved and immediately replaced the transmission control module (TCM) and I haven't had any issues since. That was over 10,000 miles ago.

[arpad_m]

Originally Posted by avalonandl

The real fix is swap to an M6 car.......

Trust me, I thought about it, and it would've even been cheaper. In the end, however, it just does not appeal to me any more. The situations where I miss the stick are relatively rare (arbitrary quick downshifts), and if the paddles or the console shifter were a bit faster, the auto would work better in 100% of driving situations.

Yeah, I get the points about rowing your own gears and the revoked man card and all, but these things (or having the V8 vs a V6 or I4) don't make a man. Plus, with all its faults, the A8 is no longer your grandpa's 4-speed auto, it is pretty darn good, those WOT upshifts in performance shift mode are intoxicating. I hear the A10 is even better, perhaps I'll have a chance to try it one day.