Case you run across this, feed speed through ADF is normal so eliminates bad tire rubbers... the actual fix is whats called "Feeler DS2 " To get to it, pretty simple, take the ADF apart (start with two screws to remove front and rear covers) remove the ADF actuator (two screws) remove two screws to get the ADF out, then disasemble front side (another 3 screws) and the metal guide should swing down revealing the black feeler.

The feeler is paper detector, over time from paper slamming into it it goes from rounded to pointed. Simple fix, pops in and out with pressure. Just be carefull not to break the taps. reattach spring onto new feeler, youre good to go.

Part Number: DA70144060