Maybe Hippo can help here.
Correct me if I'm wrong but isn't the primary similar to the differential in rear wheel drive cars? Both serve same function. I saw on another post where someone said you can run synthetic 75w90 in the primary. Now I'm not about to just do this and definitely ain't asking local h-d shop for opinion(already know what their response will be.
Hippo, you comments or anyone else?
Correct me if I'm wrong but isn't the primary similar to the differential in rear wheel drive cars? Both serve same function. I saw on another post where someone said you can run synthetic 75w90 in the primary. Now I'm not about to just do this and definitely ain't asking local h-d shop for opinion(already know what their response will be.
Hippo, you comments or anyone else?