Laserjet 4+ jams after fuser

[Dolm]

My Laserjet 4+ will feed through the fuser now after replacing the main gear assembly, but now sheets stop after coming about 1/4 of the way through the fuser. They dont reach the exit rollers, just stop there and give a paper jam code. Any ideas what may be causing this?

[raz]

generally;i would bank on the fuser itself or something right in that area.