Ferrari-CS

Car has 38,000 miles, does not have PDCC. Noticed the whining about 2 weeks ago. The pitch gets higher the faster I drive but is not dependent on gear or RPM. Suncoast initially said "it will probably resolve w/ fresh Michelin pilot SS and alignment." (>$1900) Well it didn't. Thank you Porsche! After only a test drive on new tires they now tell me: "we think your rear differential is bad. It comes from Germany as a complete assembly and will take about a week to receive. Replacement will cost about $5900." Thank you again, Porsche! I'm looking for alternative solutions. I am flushing the rear differential fluid and filtering the old stuff to look for metal or other materials. I'm sure this is the original fluid, but I cannot understand why a rear differential would fail so soon. What should the old fluid look like? It's pretty dark brown, not quite black with no obvious metal particles. I am also trying to locate a rear differential that is reclaimed from a salvaged Panamera S. Anyone have experience with this or have constructive suggestion, please?

Ferrari-CS

The old differential fluid left nothing when gravity-drained through a coffee filter. But there was a minute amount of gold particles, much smaller than glitter or sand grains, at the bottom of the drain pain (much less than 1 gm). The differential capacity is said to be 1.1 litres, but only about 1000cc drained. I refilled w/ 1.1 lt. This did not resolve the noise problem on test drive. I would appreciate any input.

pmichaelis

How do you "know" it's the differential, why not something as simple as a wheel bearing ? I would suggest an input from another Porsche expert, at that price a second opinion makes sense to me.

extanker

a whine from ring and pinion usually does not change with a fluid change. Good news is they can whine for years and not break down on the side of the road,i would go the salvage route until i could not take it any more