I changed my cuda's 3rd member unit in 1979 to a 3.91 sure grip. I haven't done anything with the gear oil since then. I am planning on changing the oil and making this a spring project in 2014.
-Do I drain the fluid from the fill plug by siphoning it with a hose?
-I need a recommendation on oil type, weight, brand....and any other additives that may be needed.
And yes, I kept the original stock 3.23 unit with 27,000 miles on it.
