Gearbox Oil Drainage Plug

I'm doing a complete fluid change in prep for a trip through Arkansas and am having a problem.  When attempting to reinstall the gearbox drainage plug I screwed it most of the way in and then switched over to my torque wrench to get it tightened up to spec.  The plug seated itself against the gearbox but wouldn't tighten up to spec, it just kept spinning.  When I pulled it out, it had metal shavings all over it (I thoroughly cleaned it before reinstalling).  I don't want to clean it and try again for fear that it will cause more damage.

Has anyone experienced this before? Really hoping it's a "quick" fix so I can go on my trip this coming Wednesday.

Thanks.

If they have been tightened by someone inexperienced they are easy to strip. I'd also avoid a torque wrench as being a coarse thread they are easy to strip. Best thing to do is stick a helicoil in.

You've stripped the thread. It's a VERY easy thing to do, especially as they get a bit older. I stripped my engine oil drain plug last week, and I hardly tightened the damned thing at all> So I feel your pain. In my view a Timesert is the best answer. I don't know what sort of level of mechanical competence you have, but it is possible to do yourself. The kit comes with a drill bit, countersink, tap, and thread insert. You drill the hole slightly oversize, countersink and tap it, and screw in the insert. I always use two crush washers afterwards, as if you hand drill them they are rarely 100% square. A competent bike shop will do it. So long as you have good access to the site, its pretty painless. People may be along shortly to tell you its a disaster to do it in situ, and you need to get the casing out, but with some grease on your drill and tap you can avoid most swarf going in. And its only aluminium.

Timesert is a better option but the problem is that they are generally longer and harder to grind down than a helicoil which can be clipped to the required length.

While a 'Sert is unlikely to be so long it fouls the gear above it it will, if not shortened, prevent the oil from draining fully. That isn't something that would worry me overly as there is always some oil left behind and the gearbox change intervals are ridiculously conservative but I know people do fret about such things. The case itself is quite thin so not much length is required.

Thank you all for the info! I have a helicoil kit arriving tomorrow. Hoping that will get things right and I can then post some pictures from the ride this week.

Thanks again for the guidance and I hope you all are having a great holiday weekend.

Cheers!

Well, not sure if this is a major issue or not.[You must be registered and logged in to see this image.]
I was putting in the cap/dipstick on the gearbox and noticed that half of the threads on the inside are not there.  This is either an Italian cost cutting measure or something really bad.  Is this normal or is this a trip to the shop?

Disregard the last. I was told by a friend that it’s just the profile of the casting. Now to fix the drain.