I have posted twice in the past week about noise from my rear differential on my 99 f150 4x4. I think I have it narrowed down to the clutch pack and I am going to have to drive about 30-40 miles to the shop where its going to be fixed (quoted around $600 over the phone). My question is what kind of damage can be done internally or what is the worst thing that could possibly happen to the diff during my drive, if it needs to be towed maybe I should go that route. What are anyones thoughts?