_________________________ Yikes, sounds serious. You won't learn much without a lab report so grab a test kit from Blackstone Labs asap. Then change the MTF while keeping a few ounces for the lab, draining directly from the case into the sample bottle. For now just replace MTF using Honda OEM while waiting on lab results. (Honda will do MTF change as well, AND will capture fluid for the lab test if you explain how. I paid Honda about $50.00 when supplying my own MTF) Besides Blackstone Labs, I also like these guys: http://www.oaitesting.com as they include TBN test for roughly the same price (no $10.00 upcharge like Blackstone) but TBN (total base number) is more of a factor when analyzing motor oil. It shows how much life is left in the fluid to neutralize acids. In any event, Oil Analyzers has a good database and does fine work. Either way it's about $25.00 for the lab work whoever you use. And only that test can tell you if everything is okay... or not. I used Amsoil MTF (not recommended for limited slip) and almost toasted mine. Got lucky. Not sure what you mean by the "diff whine". You mean a hi-pitched sound when cruising along in 5th or 6th gear? Humm. Just guessing here but I seem to recall that 6th gear sits low in the case; therefore should get plenty of fluid unless MTF is dangerously low. Very unlikely. Anyway, you'd best get on it. P.S. If this is a DIY: Not sure what car you have but most take 1.9 qts. MTF. A 3' long clear tube comes in handy (plus 17mm socket and wrench) as it's best to pour from above engine while somebody stays below to keep tube properly inserted. Keep pouring MTF until excess begins to come out of fill hole. Fluid should then be level with bottom of fill bolt, which is perfect. Simple job except for access to drain and fill bolts. Should be a YouTube or something on 9th Civic if you want to tackle it. Good luck!