I replaced a Moen kitchen faucet cartridge but was left with a black plastic ring that pulls apart. Looks like this omission has led to the faucet being very loose and sometimes the water gets stuck on as something's not catching when I push the faucet to off. Anyone know where this black ring goes or if there's another way to tighten everything up? Help appreciated!

I followed this YouTube video but there was no sign of the smaller black plastic ring. There was a thicker black "retainer" but this was put back on.
http://www.youtube.com/watch?v=-bD-89_Er3Y&feature=fvsr

That video isn't bad but Moen has its own tutorials which are better. You can also talk to a Moen Tech on the phone. Replacement Parts