Hi everyone.

I'm in the process of tackling the engine and gearbox on my 101 kit and now dunked all the bits in my new degreasing tank.

I have found that the lug on the gearbox which I believe is for the chainguard is broken off.

Does anyone have a good gear casing to hand that can provide the original size for this lug?

Looking at the remains on my casing, I would estimate about 3/4" diameter and standing off the casing by 1/8" - however this gives a drilled hole of only about 1/4" deep and not much thread at all for the chainguard stud.

Any help most welcome. Thanks.

Here's mine.

Many thanks for your replies.

I have poked around in the remnants of the hole and found muck in the bottom so now I see there is approx 7/16" deep pilot hole which makes more sense for the thread for the stud to fit.

I'll be off to Exactweld in UK soon to pick up other (Triumph!) part so will see if they can do a "while you wait" service on building the lug, boss ... protrusion or whatever back up to shape.

Now got crankcase split to sort out big end. Good news is that it doesn't look like it's been apart before. Picture attached.

Best regards to all.

P.S. Tim if you are in the UK for a while and getting bored, you are most welcome to visit sunny Sussex!

Progress!

Broken gearbox lug built up with weld and boss machines flat tapped and re-profiled on the Bridgeport mill.

Rest of the weld dressed back with a "Blacksmiths" type file - good for horses hooves and good for aluminium!

Now looks more like it should.

Oh and in reply to last post, what looks like a crack is just where the sand casting mould divides.

Pictures attached just to show that (slow) progress is being made.

A bit more cleaning up and it'll be good as new.

Cheers Mick

The welded repair was done by Guy at Exactweld in East Grinstead UK using TIG.

Not exactly sure of the welding rod used - didn't think to ask.

Regarding the old weld on my rear frame lug, I'll give the weld a good inspection when I get it blasted. This should show up if there's any cracking going on there.

Cheers Mick