I have a 2001 Nissan sentra SE 2.0 with a viscous type LSD. The car has a 100,000 miles on the stock oem gear oil. I want to change it, the car calls for a 75w90. Nissan didn't event stock gear oil for my car only 75w85 synthetic which they use in 350z and didnt even know or have or was able to get me OEM fluid for my car. I'm just a little skpetical of going with some of these synthetics. I hear so many stories of grinds occuring and certain synthetics causing harms to the seals and the brass in the tranny. Should i go with the traditional dyno or synthetic and what brands do you guys recommend. Thanks