Lexmark T Series -- Bevel Gear Replacement

The bevel gear that drives the vertical power-take-off (PTO) shaft for add-on trays occasionally breaks, or wears at its upper bearing so badly that it loses mesh. Pictured below is the gear in place at the front of the drive-train.

The method for removing and replacing it is a bit odd, but it does work and nothing ever breaks, even though it seems at times that something might.

To remove the gear, first pull the vertical PTO shaft w/spring out through the bottom of the printer. Then place your thumbs on the upper surface of the protruding bevel gear and press downward forcefully. The top end of the gear will pop out of its bearing. Here's a view of the gear having just been dislodged.

Note the thrust washer. Printers that have an add-on tray installed experience a constant upward thrust on the gear. Prior to the addition of the thrust washer, the gears would tend to wear quite badly where they rode in the upper bearing. The gear would keep moving upward until it would lose mesh. When installing a replacement gear, grease the upper end of it liberally.

To install the gear, get it into position so its upper end is nudged up against the upper bearing's opening, get your thumbs on the gear's teeth and press upward and inward forcefully. The gear will snap into place. Make certain that it's all the way up. When the gear is correctly installed, its lower end is concealed by the lower bearing, as in the first photograph above. Reinstall the drive-shaft w/spring and you're done.

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