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Broken worm shaft (and subsequent broken gearbox)
Hello everyone,
We had a gearbox lock up at about 150 degrees the other night (while I was bowling league on that pair, no less). Nothing out of the ordinary, no odd sounds or anything like that. She just stopped with the rake halfway back. What we found the next day was interesting. There was a significant amount of damage to the end of the worm shaft, it had broken apart and there were chunks floating around inside the gearbox. The HM and me cannot seem to figure out the "why" or "how" on this one. I'm going to try to get all the relevant points in here, but we'll be happy to fill in any additional info. If anyone has seen this before or knows how it could happen like this, we'd love to know!
1) If you look at the worm shaft you can see that most of the (teeth? thread? I dont know what you call it) in the center is gone, leaving not a whole lot of contact with the bronze gear. It looks very smooth underneath the parts that have broken out, almost like it's been like that for a while and has worn smooth. Could be wrong, but that's just what it looks like.
2) The bronze gear is almost fully intact, with the only damage right at the spot where it bound up, and most likely coming from me trying to use force to manually back up the gearbox to get the deck on the floor. In hindsight, this was probably a bad idea and we should have just taken the deck shaft pin out and lowered it by hand.
3) The chunk of worm shaft got wedged between the side of the shaft and the gearbox, cracking it (again, only made worse by us thinking that the bronze gear and not the worm was toast, and trying very hard to back the machine up).
4) We found something interesting... someone poked a whole bunch of holes in the back of the curtain wall right above that lane to spell out an obscene word. It looked really fresh. I thought for sure someone had sabotaged that lane and that we'd find an allen wrench or something tossed into that gearbox, however there was nothing.
5) Machine was running nice and quiet right up until it stopped.
20120517170140.jpg20120517170208.jpg20120517170229.jpg20120517170236.jpg
We had a gearbox lock up at about 150 degrees the other night (while I was bowling league on that pair, no less). Nothing out of the ordinary, no odd sounds or anything like that. She just stopped with the rake halfway back. What we found the next day was interesting. There was a significant amount of damage to the end of the worm shaft, it had broken apart and there were chunks floating around inside the gearbox. The HM and me cannot seem to figure out the "why" or "how" on this one. I'm going to try to get all the relevant points in here, but we'll be happy to fill in any additional info. If anyone has seen this before or knows how it could happen like this, we'd love to know!
1) If you look at the worm shaft you can see that most of the (teeth? thread? I dont know what you call it) in the center is gone, leaving not a whole lot of contact with the bronze gear. It looks very smooth underneath the parts that have broken out, almost like it's been like that for a while and has worn smooth. Could be wrong, but that's just what it looks like.
2) The bronze gear is almost fully intact, with the only damage right at the spot where it bound up, and most likely coming from me trying to use force to manually back up the gearbox to get the deck on the floor. In hindsight, this was probably a bad idea and we should have just taken the deck shaft pin out and lowered it by hand.
3) The chunk of worm shaft got wedged between the side of the shaft and the gearbox, cracking it (again, only made worse by us thinking that the bronze gear and not the worm was toast, and trying very hard to back the machine up).
4) We found something interesting... someone poked a whole bunch of holes in the back of the curtain wall right above that lane to spell out an obscene word. It looked really fresh. I thought for sure someone had sabotaged that lane and that we'd find an allen wrench or something tossed into that gearbox, however there was nothing.
5) Machine was running nice and quiet right up until it stopped.
20120517170140.jpg20120517170208.jpg20120517170229.jpg20120517170236.jpg
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