My 2013 Roush has developed a rear end whine that has slowly been getting worse over time. It is most apparent from 30-60mph. Truck has 150,000 miles on it and I do quite a bit of light duty towing with our race car and trailer. I popped off the rear cover and there was significant gold colored flakes in the fluid, leading me to believe a bearing is on its way out. Ring and pinion look ok with no abnormal wear or chips on the teeth. I did a 60/40 mix of Lucas oil stabilizer and Motul 75w90 GL5 which has quieted it down somewhat in the meantime, but its going to have to be rebuilt soon. Are oem parts the way to go or is there a better aftermarket option? Thanks.