Vernw

GXinSD518

You're already looking in the right direction. Good service records and regular maintenance done on time is key to getting a GX with the least amount of issues. Catching up on maintenance (tires, brakes, fluids, filters, belt, spark plugs, etc) can be costly.

The 4.7L V8 is arguably the most reliable engine Toyota has produced, nothing really goes wrong with it. Just make sure the timing belt and water pump was changed at 90k or recently.

Other common issues that I can think of:
- Leaking rear suspension air bags. Over time the rubber bags crack and no longer hold pressure. Symptoms are bottoming out on mild bumps. Easy DIY fix. Good aftermarket bags are available. Many people choose to just convert to a standard spring setup when the bags fail. Lots of aftermarket spring conversion kits are available.
- '05 and up have a secondary air injection pump to aid in emissions. These pumps can burn out, causing a CEL and limp mode. Bypass kits are available.
- Expect to replace CV axle boots or axles. Many people have had to replace them around 150k due to leaking or torn boots.
- Expect to replace the radiator if it's still on the original one. Stock radiators tend to leak at the interface between the metal fins and plastic housing. Aftermarket all-metal radiators are available.

You can also get tons of good info on the GXOR group on Facebook.

nbharathi

Check for radiator leak, i bought a 06 2 months back, there was an old leak and an active leak
Inspect all the radiator hoses
Transmission oil
rear air suspension
spare tire under the vehicle
Rust
open the hood and checkout for a sticker that says when (and what miles) the timing belt and water pump was changed
Get down and look underneath for any active leak or wet oil spots in the under carriage

Vernw

470SNC

Also make sure to check the transfer case for leaks as well.