[Mark0Maro]

First off. I store my ‘18 Camaro 2SS in the winter and I don’t drive it much. It sits a lot. Garage queen. Lol.

I had a weird vibration yesterday like I drove over bumps on the road. Drove back over that same road and it didn’t vibrate and there’s no bumps.

The vibration only lasted for 10 seconds and went away. Was wondering maybe if a brake Caliper/piston got stuck and unstuck. Idk. Before that happened I did a quick 100 mph pull. (Which is just cruising in this car).

What do you guys think?

[LT1gen6]

Tire flat spots

[Mark0Maro]

Originally Posted by LT1gen6

Tire flat spots

Yes. That too.

[dmcmahan60]

If it is an A8 car it could be the shudder problem showing up?

[Mark0Maro]

Originally Posted by dmcmahan60

If it is an A8 car it could be the shudder problem showing up?

Edit: I searched and found some information. Thanks

Yes. It’s an A8

[TP2SS]

Originally Posted by Mark0Maro

Edit: I searched and found some information. Thanks

Yes. It’s an A8

TSB 18-NA-355. Get it done ASAP. Do not wait thinking it's better, it'll only get worse and then the damage is irreversible without a new TC.
You are probably still under the powertrain warranty, so it should be free. Don't haggle with the dealer on it, the TSB clearly states "no other verification other than customer complaint needed". Make them do it no questions asked or take it somewhere else that will.
My wife's '16 CTS4 started doing it at around 40k, and since I was aware of the A8 issue, I took it in and they did the TSB. Hasn't exhibited the issue since, and now at 55k.
I had my '16 2SS done even though it didn't have the issue, as a preventative measure. First dealer told me they needed to verify it, I walked. Second dealer said the same until I pointed out the wording of the TSB, then they did it.
If you have to pay for it OOP, it's about $450.
Have it done at a GM dealer, NOT a 3rd party shop. It takes specific equipment and must be done a specific way per the TSB. A 3rd party shop is likely to just "drain" it and fill it. That may work if you do that completely 3 times, but that's a lot of fluid to buy and dump!

Mines a garage queen too! Summers only. 5700 miles on it (in fairness, I bought it in Dec '19 with 1880 miles on it). Drove it in the rain for the first time EVER last week.

[dmcmahan60]

Get the fluid flush done ASAP like TP2SS said

[ChevyTech77]

Originally Posted by Mark0Maro

First off. I store my ‘18 Camaro 2SS in the winter and I don’t drive it much. It sits a lot. Garage queen. Lol.

I had a weird vibration yesterday like I drove over bumps on the road. Drove back over that same road and it didn’t vibrate and there’s no bumps.

The vibration only lasted for 10 seconds and went away. Was wondering maybe if a brake Caliper/piston got stuck and unstuck. Idk. Before that happened I did a quick 100 mph pull. (Which is just cruising in this car).

What do you guys think?

If this was at the beginning of a drive cycle, after the vehicle had sat for a long period of time, it’s most likely just flat spotted tires.

[Mark0Maro]

Thanks man. So the shudder starts, like it feels you’re driving over bumps?

Originally Posted by TP2SS

TSB 18-NA-355. Get it done ASAP. Do not wait thinking it's better, it'll only get worse and then the damage is irreversible without a new TC.
You are probably still under the powertrain warranty, so it should be free. Don't haggle with the dealer on it, the TSB clearly states "no other verification other than customer complaint needed". Make them do it no questions asked or take it somewhere else that will.
My wife's '16 CTS4 started doing it at around 40k, and since I was aware of the A8 issue, I took it in and they did the TSB. Hasn't exhibited the issue since, and now at 55k.
I had my '16 2SS done even though it didn't have the issue, as a preventative measure. First dealer told me they needed to verify it, I walked. Second dealer said the same until I pointed out the wording of the TSB, then they did it.
If you have to pay for it OOP, it's about $450.
Have it done at a GM dealer, NOT a 3rd party shop. It takes specific equipment and must be done a specific way per the TSB. A 3rd party shop is likely to just "drain" it and fill it. That may work if you do that completely 3 times, but that's a lot of fluid to buy and dump!

Mines a garage queen too! Summers only. 5700 miles on it (in fairness, I bought it in Dec '19 with 1880 miles on it). Drove it in the rain for the first time EVER last week.

[Mark0Maro]

Originally Posted by ChevyTech77

If this was at the beginning of a drive cycle, after the vehicle had sat for a long period of time, it’s most likely just flat spotted tires.

I drive it for 40 miles or so after winter storage before I felt like driving over small bumps

Also I have until this December before the 5 year warranty runs out.

[cjperformance]

Originally Posted by Mark0Maro

Thanks man. So the shudder starts, like it feels you’re driving over bumps?

Yeah, like driving over the rumble strips on the side of the road. That bad... at least mine was.

[Mark0Maro]

I didn’t read up on it much yet.

All it needs is a transmission fluid flush?

[FlukeSS]

Originally Posted by dmcmahan60

Get the fluid flush done ASAP like TP2SS said

And don't wait either.

Waiting to long can damage the torque converter.

[FlukeSS]

Originally Posted by Mark0Maro

I didn’t read up on it much yet.

All it needs is a transmission fluid flush?

The issue occurs between I think 20mph and 80mph when just cruising and applying very mild gas pedal. For me, it happened at 50mph and 70mph on my 2016.

If it is early enough, it is a triple trans flush.

TL : DR GM put the wrong transmission fluid in the cars, and it has the wrong viscosity. Which causes the shudder and can damage the Torque Converter if letting it go to long.