Laserjet 4320tn - Black marks on side of page

Please see the 3 photos below:

http://imgur.com/Ay2yHXL

http://imgur.com/j5jpaMv

http://imgur.com/XBjGsvV

I am getting marks on the paper...I bought a new transfer roller and that heavily reduced  of black lines down the side of the page and so the issue and was left with the above. I cleaned the inside with some paper towels and I also tried using another toner from a 4250 and I get the exact same issue.

Would it be worth switching the fusers around too?