[needmorehp]

I wanted to ask a general knowledge question about a repair which was done by GM (Chevrolet) certified service shop here in Texas. The vehicle has 115000 miles and the rear driver side axle seal on the differential was leaking, I maintain the leak over the weekend by adding gear oil until I can get it to the shop. The tech of the shop mention some rear axle noise to his service director when he just told me but anyhow; was charge to have both seal replaced and top off with gear oil which they state the noise improved ( these are the words of the director). So I paid my dues and was on my way, on my way about 47 miles of driving I started to hear a knocking/rumble while taking a curve then a loud grind from my rear, and the vehicle came to a screeching stop in the middle of the road. I got out and noticed the rear of my vehicle was cover in gear oil splatter like before from the last seal leak, when I got under the car and took the best video I could which showed both replaced seals were leaking. Now the service shop whom replaced the seals and did the labor is stating I had a preexisting problem which cause the axle gears to be stripped to blow both seals (lol). My question is have you every hear such a thing where this is plausible???? Don't know if anyone with differential knowledge could help but I've ran out of online information about this, and my only thoughts are that the seals were probably replace poorly, incorrectly or technician error resulting in a greater leak cause the differential/ axle gears to become a bigger out of pocket expense. Helpppp