07 sport trac. 2 wheel drive. Loud roar from the rear. Starts at 75 mph, gets much worse at 80 mph. 107 k miles on vehicle. 4.6 l engine. During roar, places the car in neutral, no effect. Mechanic said either universal joints or drive shaft balance or cv axles. Said nothing about ring and pinion in the dif.
So don’t you believe the mechanic? Did the mechanic put your Sport Trac on a lift to confirm, or drive it? Or just toss this diagnosis at you while chatting next to it in the parking lot?
If you just want a 2nd opinion, I’d say sure, could be either of those, could also be the diff but I haven’t heard it, or looked at it or touched it and that’s what is required to confirm.
Could also be a really bad set of rear tires!