Hope you can help me out. I live in Denmark and "newer" mustangs like my 06 is not that common here, so i figured i could try and ask you guys.
I bought a 2006 4.0 V6 auto a couple of weeks ago. It has about 124.000 miles on it, i don't know the service history of it.
It makes a really weird sound from the rear and i can force the sound doing 90-100 miles an hour. The sound is like when your tire touches the fenders, but at the height of the car, that's deffenetly not the issue
Today we lifted it at tried driving in free air (that was fun...) and the mechanic said it sounds like its comming from the rear differential. But the sound when we tested was more like a metallic chirping sound instead of the usual "rubber-meets-fender" sound.
Anyway, the oil is completly black in the diff. and should be changed no matter what. At the same time we will change the auto tranny oil.
Do you have any suggestions on what this sound could be? Maybe there is a known issue with the v6's you know better than me. It seems to follow the gas, meaning when i put it in neutral it will stop (mostly).
As mentioned it can be forced doing highway speeds but can also appear when doing 5-10 miles per hour randomly.
And at last, i found a local who is a distributor of Royal Purple, should i get that for the tranny and diff? How many liters do i need for the tranny and the diff? And are there any gasket and filters that needs replacement?