Timing belt and water pump should be done sometime soon but many go even another 30-40k miles but you take a chance of being stranded if it does break.
Check your rear axle seals for leaks and just do a good inspection over the whole truck.
Every 30K gets a complete drivetrain service including diffs, trans, tcase, coolant. Plugs and air filter are also done. Tbelt, drive belts every 90 +. Other than that, keep tabs on your brakes and any oil leaks you might find
