Transmission Shuddering/Slipping/Delayed Shifts

[Buickregal1995]

I have a 2016 Regal FWD with just under 40K miles. I bought it with 8K miles back in 2019 and it initially drove flawlessly.

In the past few years, I've noticed the trans has been randomly acting up at times (shuddering, delayed shifting, pre-mature shifting, slipping, and everything in between) and seems to be progressively getting worse. I have noticed when it is cold and wet outside, it seems to be mostly fine. It tends to act up the most in the warmer weather (70 degrees and up).

Some drives it might act up once and other drives every few shifts feel off. When I brought the tech from the dealer on a test drive, they felt it once, but said it could be a normal characteristic of the trans and sent me on my way. I've read several forums about how the transmission learns shifting patterns based on driving style so I asked to dealer to reset the computer to see if that would help any (hasn't seemed to make a difference).

The most common instance where I can get it to act up is if I am slowing down and speeding back up (think stop and go traffic). When re-applying the gas, I'll hear the sound of a metal plate engaging and will experience a shudder. Typically after the shudder, the next few shifts in a row are very awkward (slip/delay/pre-mature shift) until it is fine again. I can even be on a very flat straightaway with cruise control set at 45MPH and will sometimes feel a random shudder/slip (RPMs seems to stay the same when that happens so it's not like it's trying to up/down shift).

Only other thing worth mentioning is about a year ago I popped the hood for something and noticed seepage around the trans reservoir cap (picture here). When I showed the dealer, they said that some seepage can be normal depending on temp outside and "other characteristics" and sent me on my way. Dealer has extensive notes from when the vehicle was still under warranty and said they'll get it covered only if they can duplicate and find something wrong.

Help!

 

[bugspop1]

40K doesn't mean much if that 40k is sitting in Traffic a lot.
Sitting in traffic is hard on Fluids as well as the engine (Oil, Transmission Fluid, Coolant, etc...)

What's your Transmission Fluid look like?
Is it Red?
Is it Brown?
Maybe something in between?

If it's anything but Red, you may want to change the fluid!
Even a Darker Red, you may want to change it.

You should be able to Check the color on the Dipstick
that's attached to the Fill Cap.
If you can't tell by what you see on the dipstick, wipe the
dipstick on a White Cloth and look at what's on the cloth.

I recently changed my Transmission Fluid.
I wasn't having any trouble with the transmission, but I bought
my Regal 3.75 years ago with 88k and I wasn't sure when the
Transmission Fluid was changed last (or if it was ever changed).
My fluid was a Darker Red and I was glad I did change it.
At least now I know where I'm at with my Regal and the fluids.

 

[OB1]

drain and fill check when warmed up and running use only ac delco trans fluid, check out older posts

 

[Buickregal1995]

Thanks for the rec's! Here is the color of the trans fluid. Thoughts on color?

 

[ulycyc]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10183161-9999.pdf

 

[afireinside7710]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10183161-9999.pdf

That looks expensive

 

[Buickregal1995]

The good news (if you want to call it that) is that GM issued a comprehensive CCL (essentially an extension of the original B2B warranty) for this vehicle that extended the warranty another few years and 30K miles. It ends soon so any repairs would be covered.

I showed the dealer that bulletin nearly a year ago and they said it did not apply to my specific vehicle. I have a 2.0T FWD base model and thought it had the 6T70 trans in it but the service manager said it "did not apply to my VIN". Funny, because that bulletin is exactly what I am experiencing.

 

[ulycyc]

Call Buick direct 1-800-521-7300 Maybe your dealership doesn't want to be bothered with your problem.

 

[Buickregal1995]

I have a case open with the "General Motors Executive Resolution Team" who are the ones that issued the CCL in the first place 2 years ago. I have a follow-up call scheduled with them for tomorrow, but the dealer even told them the bulletin (mentioned above) didn't apply to my VIN and GMERT went with it and said the dealer knows best. GMERT did open a TAC case last month but the determination was that they couldn't duplicate it and my concern sounded like a normal characteristic of that trans.

 

[OB1]

flush the trans, change fluid use

 

[agaric]

but the dealer even told them the bulletin (mentioned above) didn't apply to my VIN

Look in your trunk near the spare tire area and find the build sheet decal.
It has the code for all the options on your car.
If either the M7U or M7W code is listed that's what you have.

 

[Buickregal1995]

Thanks for the insight on trunk! Sticker shows "M7W".

 

[bugspop1]

From the looks of that Fluid, I'd go ahead and do a Flush and Fill!
It looks a bit on the Dark Side of Red.

My Fluid looked like it could be close to the same color as yours when I changed it.

 

[OB1]

From the looks of that Fluid, I'd go ahead and do a Flush and Fill!
It looks a bit on the Dark Side of Red.

My Fluid looked like it could be close to the same color as yours when I changed it.

definably a little toasted (burnt)

 

[Buickregal1995]

Thanks everyone for your input so far. VERY helpful. GM called this morning and I reiterated the bulletin and told them about the color of the trans fluid. They said they will contact the dealer and will be in touch.

I took the liberty myself of calling the dealership yesterday and spoke to the service manager. I asked him why he told me that bulletin didn't apply to my car and also asked why he told me my trans fluid looked "good" when I picked up the vehicle a few weeks ago......

--As for the bulletin, he said although it may apply to my car the criteria itself may not. I told him it was my issue verbatim. He said he'll look into it and call me back but that "off the top of his head" the bulletin was for TCC issues. I agreed with him in that he should go re-read thoroughly.

--As for the fluid, he said "well the tech did say it was a little dirty but that's to be expected for the age and mileage". I told him that telling me my trans fluid looks good and dirty are two different things. Although the CCL will cover any repairs luckily, you'd think the dealer (even if they tried to make me pay for it) would recommend starting with a fluid exchange?????

 

[bugspop1]

I would think that would be the first place the Dealership would want to start!
Just like going to the doctor, they always want to start with the simple stuff before
doing a surgery!

 

[GenX239]

Did you ever resolve this?

 

[Bluest]

Shuddering is a torque converter issue. Ive experienced the same and had it repaired under warranty