I have a 02 suburban z71 I got a while ago and I've done a lot of work on it has 258k on it now I've done the power steering pump, fuel pump, knock sensors(relocated), front brakes, LF wheel bearing, alternator and serp belt it has all stock drivetrain from my knowledge with mostly highway miles on it as the first owners used it to go from arizona to Washington. I was wondering if anyone on here on here with a bit more experience and info on these trucks would let me know of anything else I need or should do to bullet proof it before I go on a road trip the transmission shifts pretty clean but from 2nd it takes a sec to shift and it doesn't feel like its slipping just taking its time if that makes sense

 

I would change tranny fluid & filter, front/rear diff & trsnsfer case fluid, and brake fluid