Seagate will fit without any problem and western digital will need trimming of the rubber
Both shall be fine , people upgraded up to 10tb
apparently all seagate are fitting well (none to minimum trimming of the rubber) I put a 4tb iron wolf as my 3tb died after 7years .
You can click “ja” a good idea was to format the drive prior to put it back into the time capsule , once in there , reformat it (quick erase) and it shall work
changed my defective seagate 3tb from 2014 to Seagate ironwolf 4tb, à slight trimming of the top piece was necessary.
to pop the bottom i was pretty successful using a guitar pick, and removing cable was quite easy with a small twizzer, carefull being close enough to the connectors and don’t force on the cable themselves.
taking out the harddrive was tricky, balance it left to righ and pick the box horizontally helped getting the drive out 2cm to get a grip and remove the whole drive.
If you use a seagate leave the Bottom left and right rubber in place and apply a bit of force to make sure the drive is in and doesn’t stick out.
to reapply the top rubber start with the left side , the right side has more space and it’s easier this way.
to reconnect the cable use a spurger to press the cables back into place .
having a strong light source like a headlamp will be helpful for this !, did it with my maglight in my mouth . You need 2 hands , one for the twizzer positioning the cable the other for the spurger to push.
the ground tape is an extra part which is glued on top, so since you have to mainly reuse the old part BE REALLY EXTRA CAREFULL and try not to put your finger on the glue or you wont be able to reuse it neither...
So i did it with success - watch out there is 2kind of motherboards -
the audio was gone on mine ( got it replace once by apple (bought in 2006 replace in 2010 failed again in 2011 but no chance to replace it, so i repaired it ...thanks i fixit )
i found it useful to get an old credit card to help freeing the case, somehow the opening tool i add was made of really soft plastic - and yes i confirm it s quiet hard to open but afterwards it s snaping back into place quiet easily
on my version the longer screw was in the middle