Leaky sink drains- metal/PVC?

[dspahn]

I have at least three leaky sinks and they seem to all have the same problem- they have metal down pipes from the drain that mate to PVC... and they leak where the material changes. It looks like they have a washer that fits tightly on the metal and a plastic collar that slips over the metal and washer and threads onto the flange which is the plastic. Is something missing here? Should I change out the PVC for metal? Any ideas are greatly appreciated. Note this affects a kitchen sink, at least one bathroom sink and a utility sink. Thanks everyone!

 

[voletl]

Which way is the washer facing the beveled edge of the washer has to be facing towards the PVC

 

[dspahn]

Looks like I have my starting point! I am pretty sure the washers are not beveled- time to head to Lowe’s- if this is it then it’s a much cheaper fix than I expected!
Thanks.

 

[CT18]

You may want to snap a few pics.