I'm not really clear yet about the direction of the lines, it appears to be a positioning issue, and such timing wheel is a typical cause, but you may check es well whether you can get access to the horizontal timing strip - a small gray plastic band which spans over the complete print width and passes through a sensor on the rear of the printhead carriage, this band collects ink vapor over time, and can be cleaned with a piece of kitchen paper towel and a little bit of window cleaner.
Since you are running a 9880 you are running a 44" printer, some of the internal hardware is at different locations or may look different to desktop printers, and access to the inside may require taking off some covers. If cleaning of the mentioned items does to fix the issue you probably need to get a service manual for further actions.