Repairing stripped gearbox oil filler hole

[jdrouin]

So, I stripped the gearbox oil filler hole almost as soon as I got my bike a few years ago. I've always been able to keep it hand-tight just enough to prevent gear oil from leaking out... until now.

Was treated to a nice little puddle at work today because the filler bolt doesn't really grab at all anymore.

Any repair suggestions? The case might be a bit thin there for helicoil, plus drilling in that spot is probably not a great idea.

Thanks,

Jeff

[Blltrdr]

If you have an iron barrel that neck that the dipstick screws into also screws into the case. My parts book shows it as illustration key #14, part #140776. This is for a 2003 style. If you call CMW they will have the part # for the newer style like yours.

[ace.cafe]

Give Chumma a call.
He has all sorts of ways to solve problems like that.
And if he has to, he can get it welded-up and re-threaded if you send it to him.

[jdrouin]

Thanks for these suggestions. I always love talking to Chumma but sending the cover for machining might be overkill. A cheap and quick fix seems OK to me here, since it's only a plug bolt that doesn't undergo much stress.

Anyone ever tried the Loctite or Permatex liquid thread repair kits that don't require drilling, tapping, or inserts?

http://www.midwayusa.com/product/986916/loctite-form-a-thread-stripped-thread-repair-kit-48-ml

http://www.permatex.com/products/Automotive/thread_compounds/thread_repair/Permatex_Stripped_Thread_Repair.htm

[ace.cafe]

I never tried those kits, but they might work.
They are doing amazing things with polymers and epoxies these days.

[Arizoni]

If you try one of the liquid thread repair kits be sure the metal gearbox surface is absolutely oil/grease free so the material can bond to the metal.

Things like lacquer thinner, MEK, acetone and disk brake cleaner work well for this degreasing because they destroy the oil/grease.

[jdrouin]

Things like lacquer thinner, MEK, acetone and disk brake cleaner work well for this degreasing because they destroy the oil/grease.

Thanks, I was wondering about that. Good to know.

[cyrusb]

Are you talking about the large filler plug in the tranny cover by the kicker, or the smaller drain plug?

[jdrouin]

The large filler plug. Turns out I already have a package of Permatex thread repair epoxy, so apparently I had intended to fix it once in the past.

Was going to do it a couple weeks ago but our carpenter showed up unexpectedly to finish a job, and then I had to prime and paint it.

Should get round to it this week.

[jdrouin]

I used the Permatex thread repair kit last night. Easy enough to do, and it seemed to work. I let everything cure for a few hours, topped off the gear oil, and put the bolt back on. It was tough to align but it screwed into place and stopped hard.

It seemed to be fixed, but this morning while the bike was warming up I noticed some space between the bolt and the gearbox cover. I used my hand to tighten it oh so gently and it met no resistance at all. Still totally stripped. Very strange.

Maybe I didn't degrease the mating surfaces well or use enough epoxy. I'll try it again tonight.

Anyone used the epoxy-based thread repair kits before?

Thanks,

Jeff

[jdrouin]

I think I finally fixed the damn filler bolt. The first time around I used a Permatex epoxy thread repair kit, which seemed to work at first, but the bolt was loose the following morning.

There's a gap between the threads and the flange of the bolt. It occurred to me that the metal washer that fits under the flange might not have been thick enough to keep the bolt from going in too far past threads and working itself loose. So I got a neoprene washer and cut the center wider to fit over the threads. It grabbed better but was still stripped.

This morning I degreased and cleaned the mating surfaces again, applied a lot more of the permatex, and inserted the bolt using the two washers. It seems to have worked this time. I showed my bike at a vintage rally this morning, and there was no oil puddle underneath it when I left. Nothing new on the garage floor, either, since I've been back. Bolt is still on tight. Fingers crossed.

Now on to that exhaust leak...

Jeff

[TWinOKC]

Hi Jeff,

I voted for your bike in the Vintage Bike show today, I left about an hour after you did and they still hadn't announced the winner.  Oh well, there really wasn't anything to win anyway, just braggin rights.

Cheers,

Terry

[jdrouin]

Thanks, Terry. It looked to me like that Moto Guzzi V7 Sport was going to win the people's choice. I wonder if Brookside Motorcycles will post the info on its website.

Good meeting you yesterday. Thanks for drawing my attention to the rally, which I otherwise would have missed. Maybe next year you'll be on one of your bikes.

Jeff