The Penray Crankcase and Differential Cleaner, No. 7612, is a chemical blend that can dissolve sludge and other deposits, and actually collect moisture so that these contaminants can be safely drained out before they can cause damage. Suitable for use in the crankcases of gasoline and diesel engines, as well as in differentials, this blend includes a combination of solvents that dislodge crankcase and differential deposits so they can be removed by simply draining the oil. In the process, it also removes harmful deposits from valve train components, pistons and piston rings. It is compatible with all gasoline and diesel engines and rear wheel or four-wheel drive differentials in passenger cars, light trucks, vans and SUVs. Also, it is compatible with all conventional and synthetic oils and lubricants, as well as gaskets, seals and bearings.