Welcome to the community, YoBromo!
Trolling_Cyborg is right. You'd need a 2.5" HDD in order to be able to use a 4 TB HDD inside a PS4!
Your only option to use that 4 TB WD drive would be to get a 3.5" external enclosure + AC adapter to use the drive as an external storage for your PS4.
However, if you insist on using and replacing your internal PS 4 hard drive, I'd suggest to take a look at the 2.5" versions of the WD Blue and WD Black. The capacity is nowhere near the 4 TB, but my guess is reliability and performance are much more important to you inside the PS 4.
Here is link to our mobile versions of the drives:
http://products.wdc.com/support/kb.ashx?id=MR29Xo
Hope this helped!
SuperSoph_WD