Dear all!
In the moment I have upgraded my TimeCapsule A1470 2TB with an 6TB HDD and it works perfect!!
Build in was the old drive, a Seagate Barracuda 2000GB.
The new HDD is a WD 6TB WD60EFRX red with SATA-III.
Speed is not the big problem (5400 rpm or more).
Why to upgrade? In our family we have 6 Macs (4 MBP, 2 MacMini) and now 2TB or 3TB is not enough any more and I didn´t want to add an additional external HDD to the TC. It is much more elegant with an internal 6TB-drive, isn´t it? All is working without anything of formatting the new drive before beginning. You can use the named HDD as it comes out of the box
Here the steps:
(always be very careful with the thin cables!!!)
1. Open the housing and remove the internal HDD (like ifixit has done).
2. Pull out the complete HDD-tray (see ifixit tear down).
3. Now you have to modify the rubber-holdings on the bottom and on the top in that way, the new drive fits exactly in there. For this please use a very sharp cutter.
4. Insert the complete tray with the upper rubber-edges into the white plastic-housing.
5. Slide in the new HDD (!!! be careful with cables!!!). It should now be fixed in the same way as the old one was. Fix all cables again, fix the 4 pieces of Torx again.
6. Close the black bottom. READY!
Now you have only to connect the TC with AC and network and open the Airport Utility software on your Mac. HDD needs to repair. So do this and format/delete and rename the HDD. After a few seconds all ist done! Fell free with a lot of new capacity!
Greetings from Germany,
Manfred