Phaser 840DP erratic jamming

[cosmicp]

My 840DP (22000 printouts) have begun to jam prints when printing doublesided. Often it happens after 30-40 pages. It prints first page of the sheet Ok, but the sheet got stuck in the upper exit when sheet has pulled back 2/3 length.
I remove the sheet, it jams again, after 3-4 jams it mostly continus printing OK until job is done. So the problem is rather erratic. No error messages.

Background:
Prior to this, I had a paper jam, leading to a small piece of paper getting stuck inside the printer. After 4 hours the printer finally spitted the piece out. Worked fine thereafter.
Almost at the same time the pins in the bottom of the maintenance drawer (sides) were so worn out that there were notches in them, leading to smeared and printouts. I attached stripes around the pins (tip from a phaser service technician), which solved the problem.

Any clues?

 

[shafqath]

Hello
Did you find anything on the paper jamming. I have the same problem.

Shafqat Shah

 

[shafqath]

Hello

I was working on the 850dp and had the same problem what I did was I took the printer apart and there is a small cluch thing that drives the top exit rollers. I took that out(remove the clamp). Take a sand paper and make the surface rough of the little rod that the thing was one. make sure not to move the sand paper left to right or right to left. Move it ONLY back and forth. Moving it left to right or right to left will make it worse

If you don't get anything please reply back

Thanks
Shafqat Shah

 

[cosmicp]

No, I have not got any responses (but yours) on this problem. The symptoms are about the same as before: in duplex mode, it works most of the time, but now and then (especially in the beginning of a job), a few sheets jam.

Did the sanding of the clutch resolve your jam problem completely?
Per

 

[shafqath]

hello!

Sanding it made a little difference, not much

Thnaks
Shafqat Shah