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.
I run Red Line in all my cars in the motor, trans, diff, and power steering. So I would suggest 75w-90 for your diff (final drive). This a great product and safe for LSD, all of my E30s have LSD. You can run an E30 with a whining diff for a long time, changing the fluid is a great place to start and then just keep an eye on it to make sure it is not leaking out at a great rate.
I use Amsoil for engine, redline for diff & trans. Probably would be a good idea to check your diff fluid level. Clean the diff. up as much as you can to be able to clearly see where it could be leaking. The rear cover gasket could leak, as well as around input and output shafts, and any of their seals/covers/gaskets.
I changed the diff fluid this afternoon, it was BLACK!! I ended up flushing it out and filling it with Redline. Drives much better now, thanks guys.
Wow that was quick! Did you have Red Line on hand or a local source? Glad to hear it made a difference!!
Local shop I use had several different oils on hand, he hooked me up with Red Line. Now I need to have the transmission flushed...
