My modulater valve was leaking as well last fall. I replaced it with one from Advance. The first one only gave me the hard shifts as discussed by Ronnie. I took it back for a different one, which shifts fine [like the factory one], but I have the shifting issue. So as I stated before, I will add the seafoam, run it for about 1-2 weeks and drain and fill with a new filter. At that time if the issue is still there I will get the modulater cleaned.