The best way to determine if a used cab-over commercial truck is in good condition is to perform a thorough mechanical inspection of the vehicle, paying particular attention to the truck's oil and suspension systems and checking for signs of rust damage. Reviewing the truck's service records is another way to help ensure that the truck has received proper maintenance from its previous owners and is less likely to have outstanding mechanical issues.
Commercial trucks are generally complex vehicles, especially those intended for towing trailers due to the additional systems required for interfacing with a trailer. Unless a buyer is well-versed in the mechanical aspects of trucks, it is often advisable to have a professional mechanic assist with inspecting a used truck to ensure that all of its systems are in good working order. The suspension system of a truck is worth special attention from anyone inspecting the vehicle due to its critical role in keeping the vehicle safe to drive and the high cost of repairs required to correct many suspension problems. Anyone examining a truck should also inspect its engine and transmission oil to help verify the truck has been well cared for by previous owners and look for signs of contaminants that indicate potential engine or transmission problems.