About to cross over 100k miles in my 2018 Tahoe Premier 4WD

[15burban]

Fluids are cheap compared to the cost of a transmission or transfer case.

 

[tom3]

I sure agree on that. If the fluid looks even halfway decent I'd pull the pan and filter, refill with new fluid. I'd want to see what's in the bottom of the pan.

 

[MrMonte]

Changing fluids when due & not beating on it when cold should keep you running for a long time but the AFM lifter failure can happen at anytime. I had my AFM tuned out for 30K miles but still had a lifter fail. I deleted the AFM with a cam/lifter swap 25K miles ago and sitting at 113K miles on my 2018 Yukon Denail that runs better than new.