1996 Mazda B3000 Truck Runs Fine On Flat Roads Hill Really Struggles There Sound

My truck runs fine on flat roads but when I go up a hill the truck really struggles and there is a sound like loose bearings. I have had vehicles with smaller engines that handled these hills with no significant problems.I have had the engine tuned. I do have a power steering leak and my overdrive does not work(I think its a crimped wire).