No.
Synthetic 75w90
A proper alignment shop can do it, it takes special equipment.
Chrysler 9.25 inch
You can look on the rear axle carrier housing at the metal tag to know what type of rear end is in a 2004 Ram 1500, two-wheel drive.
1500 has a 9.25 2500 has a 10.5 3500 has a 11.5
Phelps Dodge ended in 2007.
Chrylser 9.25 inchChrylser 9.25 inch
Inside the rear axle.
80w90, limited slip requires 4 ounces of additive.
NoNo
It is in the center of the rear cover.