Corn Head grease does work well. It seems to be different than ordinary grease of that viscosity, at least it seems that way to me. Even though it may seem odd, it's thick but thin at the same time. It thins to get into the small spaces in the gear box, but thickens so as not to leak out. John Deere agriculture dealers carry it, possibly surprisingly even up here in the north country where farmers do not grow corn.