Stripped the gearbox drainage plug on GRiSO. Need Help!

Hi,

I just stripped the transmission drainage plug on my GRiSO I always use torque wrenches to avoid such things but it wouldn't fit. I tried to be careful.. Now the plug won't tighten properly, it just keeps turning. I need some help in finding some solutions, if needed just a quick fix to get me through the season. I'm with the military and far from any Guzzi dealer for several months, I have limited tools with me and working in a small storage space. Also tight money wise. If I can finish the season as is, then in the winter I can repair it proper.

Since the plug just needs to be tightened can I simply put on loctite? Or some other strong adhesive? Any suggestions?

I've mostly done basic work on Japanese bikes. Frustrated at myself for having damaged my beloved GRiSO, I would appreciate any help.

Ian

Find a taper tap that will just fit into the hole and start cutting a new thread. Once it's started go to a bottoming tap of the same pitch and cut the thread all the way in. Coat the taps with grease to trap the scarf and try not to leave any in the box.

Buy a bolt of that pitch about 20mm long and install it with a sealing washer.

Fill gearbox with oil and go for a ride.

I used a Time-sert repair from these guys on my beloved VStrom oil drain plug a couple of years back.  Works like a champ! Proceed with utmost caution however as metal shavings and bearings don't mix. Did a couple back to back fill and flush oil changes afterwards for peace of mind. YMMV...Good luck!
drainplug.html

Thank you both for the advice. I'm looking at tap kits sold locally, one includes 10 and 12 mm sizes. I believe the plug is a M10. The fact that it currently just turns and doesn't tighten should I start with the next size up, like 12 mm? Or should I first start with a 10mm and it may still work? Thank you! I want to make sure I do this right. The kits don't mention taper or bottoming but I'll read up more on this..

If you are using an insert kit, you need the same size as the original thread.
They are easy to use but if you have any doubts it would be a good idea to get the job completed by a specialist.
The standard tap supplied with the kits needs to be fully inserted to form the new threads. How far can you go into the drain hole before you hit something?
Ordering a 'plug' tap to suit the kit is not always easy.
It may also be a good idea to buy a new drain plug.
Once completed, the new thread with the inset will be stronger than the original.

I put a helicoil into mine.
quick, cheap, relatively easy... and still effective.

but hear Mr Ropers words on trapping the scarf.

I suppose there is no armoured detachment nearby? One of their mechanics could do it?

Airbornbaby,
If you just want a quick fix & can get away with it try using some of this:


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It's kept my 66 Triumph T100ss & my 57 RE Bullet leak free for many a year; used it on the Triumph 12 years now!
It will do for a few months until you are in a position to helicoil/ re tap.
It works (assuming the seal you can get currently get on your sump is alright-ish!)... sometimes I wrap a bit of Plumber's tape on the bolt for an extra bodge!

Good luck!

All good advice. Thank you! I decided to play it safe and eventually take it to a Guzzi mechanic. Because of the distance and lack of free time it means the season is likely over. I considered using a local bike shop but there are few choices where I am. One is a custom bike place that has good reviews. But this being my baby I'm leaning on playing it safe and taking it to an experienced Guzzi tech to make sure the job is done right. All because of one little bolt haha lessons learned. Thank you all!

Any competent machine shop should be able to fix you up probably better than a Guzzi dealer.
It is a shame to call it quits on the riding season, as your best couple of months are just ahead.

I'll look into machine shops in the area. Part of it is a tight budget and the fact that I'm waiting to be posted elsewhere. So riding isn't a priority right now but I want it fixed, properly. I appreciate the advice!

Sam thing happened to me a year or so ago, because of lack of time and proper tools took it to Corsa Meccanica in Toronto. All good now.

I strongly recommend that you look on the web and read about the Time-Sert system. I did the same repair that you need to do a year or two ago after having waited months thinking about taking it to a Guzzi mechanic. The Time-Sert makes it easy to do the job right. I had no trouble, and I'm no great mechanic. Read, then decide.
All the tools you need come in a dedicated kit for your particular drain plug.
Moto