I bought a brand new 2014 Sahara JKU last year. Fell victim to the prepay oil changes. This past weekend, I went to the dealership for my 10K change and this dude wrote up my diff fluid. Said it needs immediate attention. I live in CO and it is still stock, I take easy to moderate trails in the mountains and I also hit the occasional mud and water hole. If I go and change the fluid myself is my warranty voided? Anyway, I'm going to another dealership for a second opinion in the morning before I change it at Ft Carson.