2 wd or 4 wd?
The motor is bulletproof, as is the suspension(ish).
To look for:
- everything works, people haul kids in Suburbans (despite the warnings, people still have kids) and kids spill all sorts of neat things in the switches.
- the oil doesn't smell like gas
- the radiator has been flushed, the dexcool, if it isn't flushed on a regular basis builds up in the motor with a nice paste.
- the transmission fluid doesn't smell burned, and optimally has been rebuilt recently. 180k is about the end of a normal service life for the 4L80e
- that all the fluids have been changed at least once
at 180k, the timing chain could make some noise and there will likely be plenty of oil leaks (especially at $1150). With that said, it's a roller cam motor, and as long as the oil cooler is still in place, the rings and such should be pristine.
They can, however, develop a tick from the lifters - honestly, if it ticks, get another suburban because the worst-case for that issue is a roller that isn't working and it's wiped out the cam.
suspension - as you didn't say 4x4 or 2wd, 2wd is normal stuff like worn ball joints. For 4x4, make sure it engages and there are no warnings. Make sure there are no noises or clunks when you turn.
shocks - check for leaks
bushings - you're in Arizona, rubber dies quickly there; so you could be in for a full bushing replacement (which will make it handle like new).
Otherwise, the Suburban is the best out there - there's lots of good reasons why it's owns better than 80% of the market.
