I just went to get my first oil change and also decided to have my trans and diff fluid changed as well, because I heard they tend to get pretty dirty due to the brake in period. Oil change part went find but on my receipt they listed the exact same part # (999MP-MFTOOP) for the fluids for BOTH the transmission and rear differential. I thought the rear diff used a different fluild so I called them up and asked. They told me I was "setup" and shoud not worry.
I just looked at the owners manual and it says the manual trans takes 75W-85 API GL-4 and the rear differential takes 80W-90 Hypoid Super API GL-5. So my question is will this affect the reliability of my LSD/rear diff in the long term? Should I bother making them change it again??