I finally got around to changing my rear dif fluid tonight. It is a real PITA to do as there isn't much room to get the plug off and back on, then I only had a mity vac to drain it so it took 15 or so bottles to drain. I was shocked by how filthy and milky the fluid looked. Just changed the dif fluids in Jeep Liberty that we bought for our daughter and with similar miles (about 100k on both) the Jeeps fluid was cleaner (this is on a vehicle that you should change the dif fluid every 20k) and on it the bolts had never been touched so it was never done. Looks like I will be drilling an access hole into the xk in the next couple weeks. $58 for 2 quarts of sta lube is a bit pricey though.

 

first change?

 

I changed the diff oil this past weekend on my C280 with 130K miles on it. It came out black. It was the first time I changed it when the car was new. I also changed the diff fluid my Crown Vic Police Interceptor with 147K miles on the same day when I had to change out a bad rear wheel bearing. I was shocked to see clear honey colored oil coming out! It was as if the oil was brand new fresh! I got the car at 100K miles and never change the diff oil till this past weekend. I know the cops don't change diff oil before they sell the vehicle, so this must be the first change. I am still in shock!

 

So what's the lubricant spec on a Crown Vic police special?

 

I used 80W-90. I don't know what brand Ford uses. But when I put in the new oil, it did not look as good as the old oil that was dumped out. I was debating if I should put back the old oil, but then decided not to knowing how cops drive....