Should I buy this 2017 LTC 6.2 liter--Chevy Shake?

Donnie Gregg · October 18, 2021

Thank goodness for this site. I just purchased a 2017 Chevy 6.2 liter LTZ. It only has 19k miles on it. I noticed a small vibration through the steering wheel. I thought it had to be the road as most of the 100 mile drive was smooth. On the way back, the shakes were more often and more noticable. I even felt a couple of "clunks" while slowing down to make a turn and then when I sped up the clunk happened.

I had not idea what I was experiencing unti I found this site and all the issues with the transmission of the 8 speed 6.2 transmissions. Here is my question--

Carmax gives a 30 day money back gurantee--If they can fix it through the trans flush and/or torque converter replacement--do I buy it? I love the truck and i really want the 6.2 as I am coming out of a 2007 Duramax and I feel like I will miss the power.

Most of the posts on here seem to say that it can be fixed--however, I do not want to be in the minority that it cannot be

If they fix it and I notice no issues--should I buy it?

thanks for the help

Edited October 18, 2021 by Donnie Gregg

rav3 · October 18, 2021

If it were me, I'd get to a dealer & request the "fluid change", where they put in a Mobil 1 heavy duty fluid & see if that corrected it.

Is it a certified car from GM dealer?

Donnie Gregg · October 18, 2021

Just talked to Carmax--they are sending to local GM dealer as it still under GM's 5 year powertrain warranty. I actually know the service manager at the dealership--so I will also see what he says. My only worry is that it wont fix it--but it seems like so far it has for most people

Edited October 18, 2021 by Donnie Gregg

rav3 · October 18, 2021

Good plan. Talk to your service manager friend & see what he tells you & report back. It's my understanding the new fluid (Mobil 1) is a little thicker than the Dexron VI

TSB Seems To Fix 8-Speed Automatic GM Transmission Problems

Donnie Gregg · October 18, 2021

Thanks for the link!

NWI Denali · October 18, 2021

The Chevy shake and transmission shudder are 2 different things....

Chad2815 · October 18, 2021

Tune is the only thing that will fix both….many have tried and failed. Sucks because they are awesome trucks but GM tuning is pathetic.

steelerdude15 · October 19, 2021

15 hours ago, Chad2815 said:

Tune is the only thing that will fix both….many have tried and failed. Sucks because they are awesome trucks but GM tuning is pathetic.

Yup. These trucks were tuned to be as efficient as possible, but lessened the drivability in the process. I can't wait to retune mine, but I'm waiting for the powertrain warranty to expire first.

Donnie Gregg · October 19, 2021

so what I am experiencing is a shaking of the wheel while driving--like running over rumble strips--not all the time. Also--the problem is not near as bad or noticible when I am in manual shift mode

NWI Denali · October 19, 2021

11 minutes ago, Donnie Gregg said:

so what I am experiencing is a shaking of the wheel while driving--like running over rumble strips--not all the time. Also--the problem is not near as bad or noticible when I am in manual shift mode

That is the trans shuddering. Since you like the truck, I would have the dealer do the trans flush and see if that fixes it. If it doesn't, then return the truck to Carmax.

Donnie Gregg · October 19, 2021

That is the plan--I talked to the service manager at the GM dealer--he says the flush normally fixes the shudder-thanks for the info

Chad2815 · October 20, 2021

It does for about 1000 miles and then it comes back. I would look for a 10 speed truck, haven't heard of the issue with them. Sorry I just cant imagine buying it knowing that the shake exists and waiting for it to reappear. Find someone that can tune it or I promise it will shake….and clunk.

Donnie Gregg · October 20, 2021

Chad--has this happened to you? Also, is there a plug and play tuner or does it have to be taken to a mechanic?

CrawlSlow · October 20, 2021

Use it as a leverage and knocked the price down low

Chad2815 · October 21, 2021

Yes it has happened to me. There are two variations of the shakes. The one that the flush helps is if you see the rpm needle moving at cruise. The other one is at cruise and I think its the TQ converter locking up and trying to hold the gear. I am far from a mechanic but I have read and contributed to the the nearly 900 pages of the shakes on this forum. I dont mean to be a downer on these trucks because I still love them but I feel like someone should let you mnow what your getting into. Handhelds cannot do anything to the tcm and thats where the troubles at. You have to mail the tcm off to hp tuners ($217 with shipping) then pay for 8 credits to tune ($400) and then find someone who can do it. I found and awesome guy here in KY who did it for $600 which included 4 hrs worth of dyno runs and tuning. Mine is ALOT better but we are still going to do some interstate driving while he tries to figure out what its doing. The dealer will hit you with a flush and quick re-learn for the clunk and the drive home will be awesome but unfortunately these things re-learn fast and the 3-2 and 2-3 clunk will be back. Sorry I know this is alot of info but I think it will help you make a decision.