Chevrolet rant

[clinebarger]

Update, my trusted independent shop did the transmission service, and I'm happy to report the shudder is gone and it's shifting like buttah! He told me he added a BG friction modifier and LubeGuard.

Lubegard is also a friction modifier....So you have a triple dose of FM as the ATF already has a FM package blended in.

 

[ThatNavyGuy]

The shudder issue first appeared on my ‘16 Silverado with the 8l90 at around 40000 miles. Dealer did the triple flush procedure per the TSB and it did fix the problem…temporarily. It started again about 20000 miles later..even with the supposedly new and improved Mobil 1 fluid. Two fluid swaps later as I’m about to hit 100k miles…it’s starting again. I’ve just resigned myself to the fact that I’ll be dropping the pan and replacing the fluid every couple of years at this point. It’s about the cost of an oil change to do it yourself and takes about an hour.

 

[ctechbob]

The shudder issue first appeared on my ‘16 Silverado with the 8l90 at around 40000 miles. Dealer did the triple flush procedure per the TSB and it did fix the problem…temporarily. It started again about 20000 miles later..even with the supposedly new and improved Mobil 1 fluid. Two fluid swaps later as I’m about to hit 100k miles…it’s starting again. I’ve just resigned myself to the fact that I’ll be dropping the pan and replacing the fluid every couple of years at this point. It’s about the cost of an oil change to do it yourself and takes about an hour.

You have one of the early units. According to GM it is a doomed unit no matter what, so at best the fluid changes will help for a while until they don't. You might want to look into preemptively replacing the converter with a new unit. (See my post above from thee 8 speed discovery docs)