Biz Hub di 5510 paper feed issues

[yormets]

I keep getting paper jams from any cassette with a J31-01 error. I have the manual. But what is actually failing? It appears to me it is OVERDRIVING as some of the paper ends up past the fuser blank. Is it in the secondary paper feed unit or is that misleading.? There appears to be three sensors in the secondary unit. Not lever sensors. Do they go bad? This is very frustrating. The manual tells me it is in the secondary paper feed unit. But what is failing? Roy

[yormets]

I also can run single copies all day long with no errors. You can't do multiples. Is that a clue?

[nmfaxman]

Lightly hold the jam removal knob on reg roller. If it doesn't stop, change the clutch. If it stops swap or clean reg sensor.