In my experience with Tamron lenses, they work really well on Nikon bodies. I have tried many, and own one of them. I heard somewhere that Tamron actually pays to get certified from Nikon for Nikon's AF algorithms, not sure if it's true or not.
Anyway. I bought my Tamron 45mm VC from Ebay during a 20% off promotion, the package included a free tap-in console. I paid 399*0.8+40+17=376.2USD, $40 is postage and $17 is the robbery also known as exchange fee, I used the wrong card. I have a low rate one, oh well.
I tried the lens on my bodies, and it worked flawlessly, AF is extrenely fast and snappy for both far and close objects. I sold the tap-in console for $60 new. I only ended up paying $316.2 for the lens. $320 essentially for a fast, stabilised, superb 45mm. This is just unbeatable. Maybe I'm good at this stuff due to being Chinese and having a grandpa who started from buying low and selling high
, and ultimately started a thriving business, go figure haha.
My suggestion is to just sell that thing if your lens performs perfectly. You can always dial in some in-camera tuning.