Does anyone know exactly what a tank change consists of in a 5k q? I brlieve the differential needs to come down! Plus I need a new tank if anyone knows for sure where I can get a good used tank for a decent price please let me know or e mail me Smp928s@aol.com

You don't say the year of your quatro unless I missed it. Mine is '87 and didn't require any special running gear altering to remove it. Set it on jacks and get to the top connections through a trunk access plate. Be sure tank is empty. Disconnect wiring and goose neck filler sleeve before the straps.
On the tank itself, I had a rusted one (not Audi) relined with a fiber glass material about four years ago. It is still working fine. Check the yellow pages in your area. They can patch holes or put a new lining in rusted tanks. For a new one, bimmerparts.com might be a chance for online catalog order. A new car might be cheaper. good luck!

Yes mine is an 87 5000 quattro as well. It just looks like it would be held in by the rear diff. someone else told me that the bently manual said that it had to be dropped as well. I will try what you have told me, thanks much!