Posted by Jack Smith on March 22, 1999 at 19:30:02:
In Reply to: Re: gear oil posted by Winget on March 22, 1999 at 19:04:55:
on the multi weight oils, gear oils included, an engineered polymer (plastic) is added to control viscosity. (thickness) The multi weight designation means that the oil, in this case, will, within its recomended operating range of temperatures, never exceed the thickness of 90 weihgt, and never thin down past 80 weight. The only problem with polymer additives is that they age, and as they do, the oil thickens and becomes unserviceable. Once that happens it can be a nuisance to clean out of a gear case. When possible, always use a single weight oil or gear lube, and the same goes for engine oil. There was a time not long ago when the use of a muti weight lube would void the warranty of a piece of industrial or marine equipment. Multi-weights were made for convenience, not long hard service. Try calling your local suplier and find some straight 90 weight, or be prepared to keep it changed and fresh.