My 2018 CTS presented the problem multiple ways and I've had THREE different symptoms. . .

1. Hesitation / slippage when accelerating (like it can't decide to downshift or just go)
2. a "shudder" at highway speeds that presents like a cycling vibration
3. an infrequent HARD shift from 1st to 2nd.

After around 800 miles since the latest TSB being completed (full flush with newest synthetic trans fluid) I make the following observations . . .
1 seems to be totally solved.
2 may or may not be totally fixed. I need to get my tires balanced and rotated before deciding
3 this has increased in frequency since the TSB, but is still so infrequent that I really don't have an issue with it and probably wouldn't think anything of it had I not read about others' issues

 

I contacted Cadillac and they have returned my call however we keep missing each other. I’m really disappointed with the performance of my CTS. It just doesn’t run like a Cadillac should. I sure hope that corporate will remedy my issue because I can’t keep the car with an acceleration hesitation such as I have.

 

Update. I had my car at the dealer again. The fluid flush did not help. They told me if the car doesn’t set off a code there’s not much they can do. Seems l BS to me. I did finally connect with a factory rep and after explaining what my problem is she told me that she couldn’t diagnose my problem over the phone! REALLY? I guess my next move will be to write the Cadillac CEO and copy everyone in leadership positions listed on the Cadillac website. I either get it fixed or get rid of it because I cant continue to drive it they way it performs. Kind of a shame because with exception of the trans problems I really like the car.

 

Dealers have a lot of discretion in these matters. Go to another dealer which you should have after the first "that's all we can do" response. I had the shutter on my 2016 AWD last month at only 16K miles (also the typical CUE screen issue). Since purchasing this car it would bang into gear at a stop sign on occasion and have a slight hesitation in first. It would do it so infrequently that I never took it in ( I hate the stealer experience and avoid it at all costs...even thought about replacing my own CUE screen) until the shutter appeared. Since the tranny flush it has been good although it still bangs into first gear occasionally - there is a specific TSB on this shifting issue and how to "relearn" the transmission by driving. In addition, my 2016 C7 started the shutter at less than 1,000 miles but I haven't driven it for 2 years (1,050 miles on it now) due to health issues. It's out of B@B but I did purchase a GMEPP that will cover the issue hopefully with the flush when I get around to taking it off the lift and driving it...soon. mods, this should be in the "general" section....I think.

 

Update.
After my last visit in which I was told that there was nothing more that they can do I wrote a letter to the Cadillac President with copies to the GM CEO, GM President, and of course the manager of the dealer and the dealer service director. I received a very speedy response in the form of a phone call from the Cadillac President’s office. They told me that they would be speaking with the dealer and that they would be calling me. I now have another appointment to check out the hesitation once more but I am not overly optimistic just based on the conversation with the service manager who told me that they have never had to do anything to the 8 speed transmissions besides a fluid flush. If this visit doesn’t produce any results I am going to have to get rid of the car Which is very unfortunate. They keep telling me that this behavior of the transmission is normal and I keep telling the that a hesitation like this is not normal and is at times dangerous.

 

They keep telling me that this behavior of the transmission is normal

Clipped from my reply to another post:

It's almost as if the customer facing employees were trained not to acknowledge known problems.

Fortunately, my experience with a second dealership was very different. In 20 miles or so in a different direction, I went from "Well huh, never seen that...." to "Oh yeah, we can fix that." on several items.

And as jimmie jam stated, every dealer is different, I have had a much better experience at a different dealer.

 

My 2018 exhibits the harsh shift from 1st to second and the shudder at highway speeds only sometimes. Mostly when it's cold with the hard shifts. To me this is a software issue though, no? Because when this happens, I flip to manual mode and use the paddle shifters until the car warms up and the shift from first to second is fine if I do it on my terms.
I only felt that hesitation twice, and the music was up a bit loud, so I'm not sure if it was really the start stop that I felt. The shudder was gone on my last 400km trip I took it on. Will see if it comes back. I don't know the "learning" transmission aspect of how it works, if it's always learning. But what I've been doing lately is trying to have smooth starts from 0 - 40. It would seem, perhaps coincidentally, that my harsh 1 - 2 shifts have smoothed out lately. I haven't had the trans flush yet, I'll ask for it next time it has to go in for anything else since this issue alone isn't affecting me daily. As a side note, my 2008 CTS had a transmission shudder at 50km/hr and 90km/hr for 12 years and I lived with it. They never could smooth it out but it never seemed to do any long-term harm.

 

I have the same issue. I took it in twice already. They found Service Bulletin # 16-NA-361. Google it and see what you think. I still want the problem fixed

 

Try looking at the CT6 forum. It seems like every CT6 from 2016 to 2018 has the same issues and no real cure.

 

I had the same issues. Fluid flushed and transmission computer reset to learning mode. This fixed everything for 500 miles. Then it started having a harsh 2-1 downshift when stopping. Took it back and there was some kind of software update for that. Been silky smooth since.

 

My car also exhibits the erratic shifting issue upon light acceleration. But no slaming of gears Weather its Transmission slippage or converter lock and un lock. With 8 gears theres a lot going on in there. I noticed this on my road trip. My friend works for the Sheriff's office. He told me the early 8 Speeds had a lot of issues. Early 2016 was when started to get their stuff right.

 

There is an anti-shutter additive you can try. It's made by Lube-Gard. It does work, I know from prior experience. Just get the correct color additive for your fluid type. I've been an Amsoil guy since the late 80's. I use Amsoil in everything. (Engine, trans, P/S , diff, generator, 2 & 4 stroke) However in these new (2000 and up) transmissions, foriegn or domestic, I always recommend using OE fluid from the MFG and use the additive. These aren't like earlier 3 and 4 speed automatic transmissions.

 

I've had the transmission flush, and reprogramming twice now, still my hard shift from 1 - 2 exists and still I get shudder at highway speeds. I have 30 days of warranty left on my 2018 and it's going back in tomorrow to try to get this fixed. I give up talking to them about the hard shift, "that's normal" is what I get. But there's no way they can say the highway shudder is normal or safe. I had to pull over the other week on my way home from a trip cause the shudder was so bad the whole car was vibrating. When I got rolling again the shudder was there, but didn't hit that resonance to make the whole car shake. I'll be pushing for a torque converter replacement within the next 30 days for sure.

 

Hey Philly,
I just landed on this forum after searching "2018 Cadillac CTS-V transmission problems." I just purchased a used CTS-V with 75k miles and have been driving it for only a month. I am noticing a lot of the same issue you and others are discussing regarding the heavy shift between 1-2 gear at a cold start and the shuddering on the highway freaked me out. Did you find a solution to this by any chance?

Thanks for your time in advance. Really appreciate the opportunity to try and get this figured out. Other than this issue the car is awesome!

 

Either way, it should be covered under the drive line warranty after the B2B runs out.....

 

I see this thread for 8 speed Cadillac/GM vehicles. I have a 2016 Cadillac XTS and 2 2018 XTS's with the same transmission shudder, but the XTS isn't listed as a problem vehicle, and I'm pretty sure they (at least the 2016) are 6 speed automatics. Anyone else have trouble with the XTS model?

 

XTS is a fwd/awd platform, problem child is the rwd/awd ala ATS/CTS/CT6 with 8L45 trans.

 

Sorry, I haven't been around in quite some time, travelling a lot for work. No, no solutions for any of my issues, and I'm hear more noises which I think are my lifters going bad on me. I'm looking at a 2022 CT5 V right now and gonna dump my CTS. I love the CTS to death but parts are hard to get and they can't ever seem to fix some issues and it's like they just don't care or support this model any more.

 

Don't get me wrong, I loved my 2016 CTS4. Ran flawlessly to 46K when I sold it in May. My CT5 Luxury Premium is by far superior (and I thought that the 16 was great). Do not hesitate to move up.....

 

Can you expound on what you feel is better on you new CT5?

 

Just about everything John. Materials and finish is better. Technology is MUCH better. Transmission is smooth and quiet as opposed to the 8L45. I encourage you to drive one. My Premium Luxury has every option but the 9K Super Cruise. MSRP of "only" 53K. My 2016 was AWD which I did not like or need so I got a RWD and I was going to do the 6 instead of the 4 but I had no issues with the 2.0 so that's what I have even though the new LSY 2.0 is about 35 less HP. It still has plenty of pep and gets about 4-5 MPG more than the 16 around town. I currently have about 4,000 miles on it and I am pleased overall. good luck!

 

Yes my 2018 it's has done it since I've had it for 3 years now the dealership says it's fine but it hasn't went out in me or anything..does it every day

 

https://a.co/d/0JGBUWs

Lubguard # 63010. Amazon / NAPA / ORAP
This additive works real well. It's an easy installation to the transmission fluid. And an alternative to the shop changing the fluid every 25k miles when the additive package is depleted.