I would have a trusted mechanic do a bumper to bumper inspection on the tow vehicle or do one yourself and service it. I wouldn't go to a quickie lube because most of the young folks who work there really don't have the experience to give you an honest assessment.
Check hoses and belts and check the transmission fluid to see if it smells burnt. Check oil/grease levels in the differential. Look for obvious issues with the frame and suspension, like rust or cracking. Check the brakes and have the wheel bearing packed if it hasn't been done is several years.
Have them pressure check the cooling system and check the coolant for rust. If in doubt, have the radiator flushed and refilled with clean coolant. You can check the radiator yourself with a handheld temperature gun. Look for cool spots in the radiator after the vehicle has warmed up. If you find them, it indicates clogged coolant passages that will lead to overheating.
The cost of the inspection itself should take about an hour and cost about $100, plus the cost of the oil change and packing the wheel bearings. The inspection should catch many of the common issues.
