I am changing the rear dif fluid (75w-90) on a 98 2.8 Quattro but I need to know if it needs a limited slip additive, does it?

Also, I am leaking from the main seal in the rear so I am going to replace that seal. Any advice? I have access to a fully equipped shop so no problem with tools.

 

No you dont need an additive. Just use a good 75w-90 gear oil.