Thank you for replying. I believe I have found the reason. The client has changed their paper stock from 20 to 60lb 8.5x14. Because it is feeding from the LCT, which only is rated for a max paper weight of 34lb, the printer is overheating trying to fuse the heavier stock.
Then someone will need to troubleshoot the issue first hand, verify everything is the same and yet still different and then replace the 4622 that would in that case have to be broken
This is the resonse from customers IT Admin:
" Hope your day has been going swell, and thank you for sending over that information regarding the PS driver vs the existing PCL6 driver. While the driver may impact the functionality or print speed, I don’t believe this is the scenario with the printer in Lezlie’s office; I currently have all of my Xerox 4600/4622 series printers running the latest Xerox GPD PCL6 driver, with the exception of the (2) high-capacity units that Lezlie has in her office, which uses the model specific PCL6 driver for the 4622 series printers [current applications/print dialog boxes require use of the device specific driver, as some functionality is missing with GPD driver that is PS].
All of the 4600/4622 devices deployed at our facility print high volume and we have not had this issue reported on any other system at this time. "
It only has 256MB of print memory, you likely are filling the cache/spooler.
To lessen the effect, use PS driver, LPD port (No LPR byte counting), if the jobs are PDF based and you make the files, use PDF/x presets to eliminate the garbage data printers don't deal with well (transparencies and improperly embedded fonts)
4622 with LCC set to 8.5x14 plain 20lb bond in a very busy shipping office.
During large print jobs, after around 1000 pages, the printer will slow down.