Chevy Transmission

I have 2020 Silverado 1500. I believe the transmission is headed south. There’s a sort of jerky feeling at highway speed or accelerating especially on a hill. Sorta reminds me of driving on a corduroy road. I have taken it to the dealership and they said “no codes - working like it should”. A friend of mine in the roofing business has had several Chevy trucks over the last few years and some of them have given him problems. He says the torque converter is going out. Truck has 39000 miles. Anyone have experience with this?

Yep. 8 speed. Just thought something could be done to it early to prevent a complete failure. Dealership didn’t seem very interested in the problem. Asked “do you pull a trailer a lot”. I pull a small trailer with a lawn mower on it about twice a month for 20 miles round trip. I don’t know why he asked. Thought the truck was designed to pull a trailer.

Change the fluid and filter using "Mobil 1synthetic Ultra Low Viscosity fluid" use at least six quarts up to eight quarts. Measure the amount drained as many 8L90 transmissions do not have a dipstick installed. The oil mentioned will come with either a black, or a blue label. Use the black label oil as it is the latest rendition of the product. You may want to change the transmission temperature wiring harness at the same time as this is cause of erratic problems without showing codes. It plugs in easily with the filter removed. 

Edited by Codger - 30 Sep 2023 at 12:45pm

that is the fluid that General Motors replaces the original with. There are tsbs out on that. It does work my son-in-law's truck is a victim of what your experiencing and after I serviced it it has been very well behaved.

I serviced his with a filter and wiring harness dumping eight quarts back into it. Immediate results and we serviced it again 10K miles later reusing the filter and the fluid was much less dark. 20K later another fluid and filter service at 100K on the clock and fluid is very bright and clean looking. No further transmission problems since the initial service. Fluid is available on Amazon and the filter kits are from Napa in this application.

Codger,
Trying my luck at uploading a picture. Just to be sure this is the correct fluid?
Thanks
Avery

I thought the blue label fluid was the newest type.

Some F150s had a vibration / converter problem in the trans a few years ago... ( also uses the LV fluid)  -- FORD recommended changing out the fluid... that worked most of the time.

Edited by steve(ill) - 01 Oct 2023 at 8:18am

Codger
I should have said I bought the truck “used” and have put approximately 12000 miles on it in almost 3 years. After re-reading your post I am not sure which one is better for my situation since the truck is used infrequently.

Thanks

Since my last post I contacted another dealership-not to one I previously used who told me the transmission was preforming like it should. The “new” dealership told me if I serviced the transmission it would void the warranty and that a dealership would have to service my transmission. I explained the way the transmission was preforming and my previous experience with the first dealership. The “new” service manager told me to bring the truck in and they would service it at no charge. I will take the truck in next week, have it serviced and go from there. I talked to another friend of mine who had the same type problem with his truck. This same dealership serviced his truck and 20000 miles later no problems.

Sounds like GM need to get their act together and get service bulletins out to their dealers about how to service these transmissions.

Codger,
Yes, I was surprised especially when he said no charge to me. We will see.

DanWi
That’s the sad part about it. There’s a service bulletin out on the transmissions. I didn’t know until Codger told me. The first dealership I went just blew me off.

Edited by AveryD12 - 06 Oct 2023 at 11:58am

Thanks. Yes, if this works out they will be “my” dealership

How did they service the trans? Was a flush and refill, or a drain and refill. If the latter, service it again in10K miles of use. I'm assuming they changed the filter also.