Chevy Transmission
Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Shops, Barns, Varmints, and Trucks
Forum Description: anything you want to talk about except politics
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=197458
Printed Date: 24 Aug 2025 at 4:29pm
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Topic: Chevy Transmission
Posted By: AveryD12
Subject: Chevy Transmission
Date Posted: 30 Sep 2023 at 12:03pm
| 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? |
Replies:
Posted By: ACinSC
Date Posted: 30 Sep 2023 at 12:15pm
|
Is it a 8 speed? Heard they've had trouble with them Good luck |
Posted By: AveryD12
Date Posted: 30 Sep 2023 at 12:30pm
| 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. |
Posted By: DMiller
Date Posted: 30 Sep 2023 at 12:44pm
| Have several friends went thru this. These are NOT rebuildable, exchange is for the case core otherwise ALL the guts get replaced. Not a good thought by GM. |
Posted By: Codger
Date Posted: 30 Sep 2023 at 12:44pm
|
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.
------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 30 Sep 2023 at 12:53pm
| Owner’s manual calls for fluid change at 40000. I will try your recommendation. If that doesn’t solve the problem. Maybe it will crater before the warranty expires. |
Posted By: Codger
Date Posted: 30 Sep 2023 at 12:56pm
|
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. ------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 30 Sep 2023 at 1:32pm
| Thanks. Will give it a try |
Posted By: Codger
Date Posted: 30 Sep 2023 at 1:39pm
|
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.
------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 30 Sep 2023 at 3:20pm
| Sounds like a solution for my problems!!! |
Posted By: AveryD12
Date Posted: 01 Oct 2023 at 7:28am
 Codger, Trying my luck at uploading a picture. Just to be sure this is the correct fluid? Thanks Avery |
Posted By: Codger
Date Posted: 01 Oct 2023 at 7:37am
|
Yes, that is correct. I could not find the correct transmission filter online so went with Napa. There are two or three filter options so snap a photo of your transmission pan to have with you.
------------- That's All Folks! |
Posted By: bemer848
Date Posted: 01 Oct 2023 at 7:39am
| I thought the blue label fluid was the newest type. |
Posted By: Codger
Date Posted: 01 Oct 2023 at 7:42am
|
My wife poured hours into researching this and found the black to be the latest. I can't quote her resource but that trans gave us fits in a 2017 1/2 ton.
I need to clarify this a bit after speaking with my wife. The blue label product is actually newer than the black label product but is not the best to use in a truck that is worked. The black label product tended to absorb moisture with short runs or very limited use. The blue lable product has an additive package to counter this, but In reality does not remain with use and needs renewed, (changed) routinely. From her understanding the black lable fluid is better overall. If you use the truck and get the fluids up to temperature routinely, absorption would not be an issue, but if it sets for extended durations, it "could" be an area of concern. Sorry for the confusion. ------------- That's All Folks! |
Posted By: steve(ill)
Date Posted: 01 Oct 2023 at 7:52am
|
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.
------------- Like them all, but love the "B"s. |
Posted By: AveryD12
Date Posted: 03 Oct 2023 at 8:02am
| I bought the truck almost 3 years ago. Have only put approximately 12000 miles on it. So it sets a lot and most of my trips are short-20 miles round trip to town. It goes for days without being started. Sounds like the black label is best for me |
Posted By: AveryD12
Date Posted: 03 Oct 2023 at 8:13am
|
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. |
Posted By: Codger
Date Posted: 03 Oct 2023 at 10:28am
|
They don't mention it anyplace I've found but the hygroscopic nature of the fluid has been addressed and in reality if the truck is lightly used either fluid will work. However, if the truck is used for pulling much, the black lable is better. Some of the additives were removed or lessened that combat heat and replaced with something different for the blue lable repackaging.
------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 03 Oct 2023 at 12:32pm
| Thanks |
Posted By: DanWi
Date Posted: 05 Oct 2023 at 8:46pm
| Neighbor has a 1500 Chevy not sure about exact year but he has extended warranty. Chevy told him torque converter is bad but because of the auto workers strike there is no torque converter available. |
Posted By: AveryD12
Date Posted: 06 Oct 2023 at 6:41am
| 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. |
Posted By: Codger
Date Posted: 06 Oct 2023 at 7:19am
|
It is refreshing to someone step up to the plate for a change.
------------- That's All Folks! |
Posted By: DanWi
Date Posted: 06 Oct 2023 at 7:21am
| Sounds like GM need to get their act together and get service bulletins out to their dealers about how to service these transmissions. |
Posted By: Codger
Date Posted: 06 Oct 2023 at 8:12am
|
There has been a lot more problems with the transmission in Cadillac division vehicles and the blue lable fluid was brought out to combat this. Once the light duty trucks started coming into play, the black lable fluid was "adjusted" to combat near the same symptoms but more aggressive faults. ------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 06 Oct 2023 at 11:28am
|
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. |
Posted By: Ted J
Date Posted: 06 Oct 2023 at 9:22pm
|
Figures, you didn't buy it from us so........ I'm guessing you've found a new dealership that you'll frequent in the future. Good Luck ------------- "Allis-Express" 19?? WC / 1941 C / 1952 CA / 1956 WD45 / 1957 WD45 / 1958 D-17 |
Posted By: AveryD12
Date Posted: 07 Oct 2023 at 6:45pm
| Thanks. Yes, if this works out they will be “my” dealership |
Posted By: AveryD12
Date Posted: 11 Oct 2023 at 7:03am
|
Thanks Codger, Had transmission serviced yesterday. Only drove truck about 50 miles since and no problems. I would never have guessed changing fluids would’ve corrected the problem. |
Posted By: Codger
Date Posted: 11 Oct 2023 at 8:31am
|
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.
------------- That's All Folks! |
Posted By: jaybmiller
Date Posted: 11 Oct 2023 at 8:47am
|
NEVER assume !!!! ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Codger
Date Posted: 11 Oct 2023 at 9:04am
|
I've seen the TSB's and it's mandated to change the filter. Worth the ask however as there are some unscrupulous dealerships out there although this does not appear to be one.
------------- That's All Folks! |
Posted By: AveryD12
Date Posted: 11 Oct 2023 at 2:48pm
|
Codger, I’m not sure about the filter. I didn’t think to ask him. I read the service ticket and it states service was performed per service bulletin (some number that I don’t remember) and says it was triple flushed using Mobile 1 synthetic LV fluid. It’s working good now and I will follow your advice and change it again in about 10000 miles. Thanks again! |