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The trans-axle uses the same oil for the transmission and rear end. EZGO calls for 30wt. non-detergent oil. If you just want to check the level with the cart level pull the check plug and the oil should be right at the edge. If you're going to change the oil pull the drain plug on the bottom, replace plug, with cart level fill until oil comes out of the check hole. Here's a diagram that shows where everything is located.