If you need to torque items like lugs, engine, and transmission parts on very large equipment like large mining trucks and loaders, you will need to invest in a Rad Gun or Hi-Torque gun. The lug nuts on a Cat 785 truck are torqued to 850ft/lbs and 797 mining truck lugs are torqued to 2250ft/lbs just to give you the idea of some of a torque values you will encounter.
For regular parts, you'll need a full metric and standard wrench and socket set and a set or two of wrenches going up to 2" for hoses and lines. Air tools or cordless impacts are always great to have and simple things like picks to remove seals and O-rings are nice to have.
