Hey guys, I have an 86' 325 es 2Dr Coupe w/ 96k miles and want to know what you guys think the good/better/best oils are for an *LSD & Transmission oil flush/change. I live in Arizona and it gets HOT during summer, recently I heard that I need to be careful about the LSD & Transmission oil I choose (not sure if this is accurate or not). *When I'm driving it sounds like a golf cart in the rear, almost like how an electrical motor sounds when its running at high speeds - a whining sound. I have a gut feeling this has to do with my differential and I hope a flush will solve the problem. There also seems to be a lot of grease on my rear axle/differential and I wonder if I need to pay attention to anything in particular. Thanks for your time guys.