Mower deck John Deere 345 Deck Throwing Grass over operator.

I have a JD 345 with a 54" deck I believe. Every time I mow, it cover,s the machine as well as me in dust and grass. When I bought it new it had a metal piece with a rubber insert on the bottom of the deck , up near the front. The rubber piece wore off in a couple mowings and I never replace the rubber . Well the metal under the mower hits on roots sometimes . So I removed it and now I get covered in trash . I tried gator blades and no luck so I went back to the original blades. I really don,t think that taking off the metal piece had anything to do with all the dust and grass because it was doing the same when it was still on . I have checked the blades to see if they were on backwords but they were fine. Any idea what could be the problem? You cannot mow over 5 minutes without having to clean out the radiator screen it is that bad. Thanks for any help Darrel