"toller" wrote

The problem is access; I can just barely touch the nut, there is no
way I could get a wrench on it to tighten it. (yes, it is loose)
Presumably there is a special tool for this, but what?

I've only put in two kitchen faucets, but ... both of them came with a
special wrench. Basically a long cylinder, with the apporopriately
sized hex fitting on one end, that you use to tighten the nut from far
below. Go ask at HD - they may well have extras or an open box or
returned faucet, from which you might borrow that wrench.

JSH