Everything is smooth, I lowered the faucet (has two water supply tubes and a pull out spray) so I got the washer and the big but and I tighten it from below where your whole body is twisted into this unbearable form inside the cabinet and under the waste pipes and garbage disposal so you can see just a little bit what you are doing. You try your best to tighten this big nut and when you are done you hook everything up and open the water and good - water out.
So you turn on turn off a few times and the faucet is sort of heavy and after a few times it starts to wobble a bit. So you get under the sink and strange enough the big nut you tightened is now loose so you tighten it again. Try again and after a few times you have to go under to tighten it again. There is no leverage there to use any wrench, well even my biggest adjustable wrench won't be big enough and even if it were, there is no room to turn one degree.
I am now all wet and sweaty. I cut myself from disassembling the old faucet. I am seriously considering removing the sink so I can get to the faucet bottom to really tighten it. Now what I will do with the double sink after it is removed I am not sure. I don't know what else to do, the faucet is a nice one - Jado single lever with a pull out spray.