8L90 at wits end

[B-train]

I have the 8 speed and like it in my 2017. It did have the stupid shudder, but that was fixed with a 20 quart fluid flush. Going out on a limb here, but what does the air filter look like, and have you ever cleaned the throttle body? Air restrictions can appear as driveability issues because it throws off certain calculations. Just a thought

 

[IAM2NY]

That's a nice looking rig!! I have a 2015 Yukon Denali XL and the 8L90 in it started shuddering real bad at lower rpms, above 2,000 rpm and it usually didn't shudder or shake. Truck had 63K miles when we bought it, and it started doing it at about 68K, it has 73K on it now and it's gotten worse. Luckily we bought extended warranty when we got it, so 2 weeks ago we dropped it off at the dealership and they said the transmission was junk. They got a hold of the warranty company and they said go ahead and put a new one it it. Dealership ordered a transmission, and we're waiting for them to get it. They said it should be here today but I haven't heard from them today so I don't know yet. Sorry I couldn't be more of a help, but my experience with the 8L90 so far isn't too good.

I actually ended up getting rid of it for a 21 suburban high country. The trans is night and day different in a good way. Rides way better imo. Not happy about the cost of it all, BUT for once in 4 years I don't think about every noise and bump the car makes while driving it.

The 8l90s are definitely junk