Add my name to the list of folks who drove less than 30 miles and cooked the diff. No fire in my case, though.
* Car has 98K mi. Stock wheels & tires, suspension, chassis, engine, everything. All maintenance done by Subaru.
* Always changed four tires at once. I keep the pressure up, but I run 'em till the edges wear out.
-- Don't reply telling me about underinflation. I tend to drive it hard.
* Got the flat in Lancaster, NH at about 8:45 PM, put the doughnut on. No problem, I've done this a million times.
* Drove into Whitefield at << 50 MPH (15 through town, 45 the rest of the way).
* Stopped for gas in Whitefield, NH (~9 mi). No issues. Drove <<50 MPH through Carroll & Twin Mtn into Franconia.
* First noticed some wierdness in Franconia. Slight pull, slight vibration, faint smell.
* Pulled off at the first exit on the Parkway. Car didn't want to start up again from the stop sign.
* Made a right turn off the ramp (car made a creak), drove it about 25 ft to get it clear. Total distance driven: ~27 mi.
* Jumped out, jacked up the car, checked the doughnut. Looked OK.
* De-torqued the lugs anyways, shook the tire around & re-torqued them. Doughnuts' on fine now, but it was before too.
* Got back on the Parkway, immediately noticed no improvement. Pulled off at the next exit (~800 ft).
* Thought about it for a few minutes.
* Checked the doughnut's sidewall. Says it needs >60 lbs. And ya know, I've got a compressor handy.
* Hooked up the compressor. Doughnut's got ~30 lbs. Swore.
* Repressurized the doughnut in ~5 mins. Waited ~25 more for the diff to cool down.
* Drove the car the rest of the way to Merrimack (~90 miles) with no issues, besides a faint hum. Arrived ~12:30 AM.
* Got 4 new tires in South Nashua that afternoon.
* Drove back to Lancaster (~130 mi) that evening. No issues.
* Drove back to VA (~668 mi) the next day. No issues.
* Got the car checked out at Stohlmann Subaru in Herndon. Estimate is $2700 for a driveshaft & cooked diff.
* Paid 'em for their investigation time but drove away unfixed. Can't swing the repair.
* It's been two weeks and I can still smell that thing if the car's been parked awhile on a hot (>95F) afternoon.
WARNING: If you're not sure about the pressure, DON'T INSTALL THE DOUGHNUT ON THE REAR AXLE!!!
I don't know what I'm going to do with the car, partly cuz the 2011's are pretty awesome-- but I'll most likely repair the ol' girl at some point and soldier on, especially with Baby #2 on the way. One thing for sure from now on... Full Sized Spare, and check the freakin' pressure before you put the freakin' spare on.