[s-cars] Help! Anyone ever hear of this??

[Steve Marinello]

The patient is an '07 A4 quattro. FOr the record, it has been modified 
with Bilstein PSS9 coilovers, Hotchkiss bars and a Milltek exhausts 
being items that might be argued to have somehow impacted the existing 
scenario.

I stopped by my mechanic to have him change my oil, as I had not been 
able to get around to it, had oil and filter cartridge, and he is 
willing to do it for me.  He always gives the car a once over while it 
is up, which has value that I appreciate.  While it was up, it was 
noticed immediately that there was oil leaking from the rear 
differential; bright, shiny clean oil, without any crud worked into it.  
We immediately started looking or the source of the leak and were 
shocked, seriously, to see that both stub/half shafts were not fully 
'pushed' into place in the differential.  The freakin' shoulder was 
fully exposed on the driver's side.  WIth a large flathead screwdriver, 
a hammer and some jiggling, the driver's side shaft slid in and landed 
with a 'click'.  Assume a C-clip locked it in.  On the passenger side, 
however, we could get no movement.  I had called the dealer, who of 
course said, well, isn't that the modified car that went out of warranty 
in April, and told me they were stacked for the next two days, so I 
drove it home and parked it.

Now the history. When I shipped this car in from W. Virginia, with 16k 
on it, it was inspected by both dealer and my mechanic and no issues 
were found, as would be expected. Modified, but perfect. At about 28.5k, 
my mechanic did an oil change and checked it out; nothing noticed except 
front pads maybe 5k away from replacement.  A few weeks later, I found 
out that there was still one oil change with the 30k service left on the 
warranty, and got the car in under the wire, which meant that there were 
only 1500 miles on the oil, but big deal, it was a free service.  I'll 
have to check the exact mileages, but they're close to 28.5k and 30k.  
The 30k service is not much more than an oil change and inspection, and 
again, nothing stated...not even the brake pads, by the way.

So, last week after returning from the Mid East and picking the car up 
at airport, I noticed some drops in the garage at the rear, and wondered 
what/why there would be anything leaking back there.  Thought, maybe 
they topped off fluids with the 30k service and overfilled it and 
something is dripping off the diff...to be checked out with the oil 
change.  Could not have expected what we found.  Oh yeah, the mileage is 
32,200 now.  Since the service, the ONLY service the car has seen is 50 
miles to and from work on the interstate.  Not even a run out on the 
rural roads west of here, which are the best I can find without heading 
to Austin.

SO, anyone ever hear of anything like this?  Any ideas?  Is this just 
the freakin' weirdest thing you've ever heard?

And, why won't the passenger slide shaft slide back in?  I'm betting a 
busted C-clip blocking it off, or something.  I see $$$ and a warranty 
expired and would really like to know how/why anything like this 
could/would happen.  Cannot see any reason to drop the shafts to install 
the coil-overs, exhaust or bar, and even then, all this work was done at 
11k , before I got the car.

What do you professional and amateur wrenches say about this one?

TIA,

Steve