DGBAMA
Well-Known Member
Figuring I had used my shredder enough to warrant cleaning and checking things, I took some time to evaluate the "grease cups" since I have not seen any guidance in how often to use them, or their function. Here's the dirty details, including a minor flaw that made mine not work properly, and one improvement to be made in the future. I initially half filled the cups, and attempted to turn them in to add grease to the gears, but to no avail, and did not want to risk damaging the fine aluminum threads in the caps, so decided to take it apart and have a look.
The gearbox, with sidecover removed:
The gearbox removed, and grease cups removed. As expected, the gear shafts are hollow, tightening the "cup" forces grease into the gearshafts. This is the back of the gearbox, showing the gearshafts welded in place, nothing to come loose here:
The male side of the grease cups do double duty as nuts, holding the gearbox together. You will need a 7/16 wrench to remove them and open the gear box.
Outer cover removed:
First step was to attach the grease caps to the gear shafts and make sure that the grease holes were not obstructed. (they were not).
The gear shafts have a spiral groove in them to facilitate grease getting to the inside bore of the gear. I found the grease hole to have been drilled after the groove was cut, raising a burr around the grease hole and preventing grease from moving between the shaft and gear.
No big deal, take a needle file and clean it up.......NOT...........file would not touch it, the shafts are VERY much hardened steel. Dremel and a small diamond bit cleaned the grooves and burrs right up though.
While apart, I wanted to know just how much grease was being added by the cups. This is two turns of the cap. So one turn at a time will be more than sufficient. Note that the groove in each of the shafts is the same direction, and the grease hole is in the center of where the gear rides. This will tend to push added grease more toward one side of the gear than the other. See summary, second post for my recommended solution.
The gearbox, with sidecover removed:
The gearbox removed, and grease cups removed. As expected, the gear shafts are hollow, tightening the "cup" forces grease into the gearshafts. This is the back of the gearbox, showing the gearshafts welded in place, nothing to come loose here:
The male side of the grease cups do double duty as nuts, holding the gearbox together. You will need a 7/16 wrench to remove them and open the gear box.
Outer cover removed:
First step was to attach the grease caps to the gear shafts and make sure that the grease holes were not obstructed. (they were not).
The gear shafts have a spiral groove in them to facilitate grease getting to the inside bore of the gear. I found the grease hole to have been drilled after the groove was cut, raising a burr around the grease hole and preventing grease from moving between the shaft and gear.
No big deal, take a needle file and clean it up.......NOT...........file would not touch it, the shafts are VERY much hardened steel. Dremel and a small diamond bit cleaned the grooves and burrs right up though.
While apart, I wanted to know just how much grease was being added by the cups. This is two turns of the cap. So one turn at a time will be more than sufficient. Note that the groove in each of the shafts is the same direction, and the grease hole is in the center of where the gear rides. This will tend to push added grease more toward one side of the gear than the other. See summary, second post for my recommended solution.