Weaver 2-8-0 noise

I mentioned yesterday that I would post some photos of the inside of another Samhongsa gearbox. Though the box I show is different than the one in Scott's loco it shows the bearings which appear to be missing on the front of his loco's gearbox. I don't think I have seen grease ooze out in the volume showing on his loco on any loco I have owned. Let me add some context to the gearbox photos I am posting. A couple of years ago we were having a discussion about the Williams, Weaver / Samhongsa gearboxes and I was trying to show how little difference there was between the 42:1 and the 21:1 version of the similar gearboxes. The primary difference was that the 42:1 version has a single helix worm and the 21:1 version has a double helix worm. A single helix moves the worm wheel 1 tooth per worm revolution and a double helix moves the wheel two teeth per rev. The second difference is that the teeth on the worm wheel have a different skew angle. For our trains, a typical skew angle on a worm wheel's teeth for a single helix worm is about 5degrees and 10degrees for a double helix. You can see the difference in the photo where I placed a straight wire between the worm wheel teeth on the two gearboxes. Since I cannot see what is inside Scotts gearbox I cannot be assured that the worm is as contained as the one shown in my gearboxes you could remove the bearings from my gearboxes and the worm would still mesh with the teeth of the worm wheel till the teeth were chewed up. Thus the grinding sound that several people have spoke of. I made some notes on a couple of my pix which I emailed to a supplier in Korea to see if they could supply said parts. They could not. Though Samhongsa made some very nice locomotives their quality control was not always what it should be. I would not be surprised if some gearboxes left the factory missing a bushing or having the worm wheels mismatched with their worm. I ran into that problem on the two gearboxes shown here the 42:1 and had a single helix worm and a worm wheel with the skew angle which matched the double helix and the 21:1 box had double helix worm and a worm wheel for a 42:1 box. If you look at my pix you will see that the parts are marked with red and green markers. I did not want to mix any parts up so I removed and cleaned one gearbox and marked it's parts with red before I removed and cleaned the second gearbox parts and marked them with green. These locos were bought new in the box from different dealers years apart and this was the first time the gearboxes were removed. So there was little to no chance anyone swapped them after they left the Samhongsa factory. The two locos seemed to run fine with the wrong worm wheels but no doubt they would have wore out sooner as the contact patch where the teeth mesh was smaller on the mismatched gears.. I did swap them before I reassembled the respective gearboxes. Surprise,, the current draw and start voltage both dropped in the locos which I swapped the worm wheels. j