Buying a Core? Here's what to check

If you’re buying a core, check this (or ask to have it checked) before buying

If a gearbox (manual or power): place a vice grip on the input splines and spin the input from lock to lock. (2.5 to 5 turns or more depending on the gearbox), it should turn smoothly. If it has a gravelly feel, internal corrosion may be present and the core may not be usable

If a power steering pump, spin the pulley or shaft. It should turn smoothly, if it doesn’t, it may not be rebuildable