AJS & Matchless Owners Club

My 52 model 18 has the bottom frame rail with the passenger footrest hanger and a stud for mounting the silencer. The thread was poor when I assembled the bike and I should have done something about it. Now the thread has totally stripped. So my question is whether this is a stud which is threaded into the bottom rail or if it was a large flat headed bolt which was brazed onto the rail. As the thread was ruined I tried removing it with a wrench, no movement. Closer inspection did not really show any evidence it is a stud in a threaded hole. Certainly I could find no stud in the parts list. Anyone replaced one?

Clive. On my '54 G3LS it's a tapped boss.
I have fitted a bolt (with a brass collar which pulls the silencer close in under the frame rail so that the k/start doesn't scrape the silencer).

It looks like a machined stud I-e short length of round bar, turned down and threaded, then brazed into the frame rail. I might be wrong,
A way round the problem, you could take of rail, cut of stud and drill, tap the boss , use a bolt , same as spriddlers post.

I started by thinking about removing the frame rail but I have a problem. The stud that runs through the rear swinging arm bridge was rusted solidly into the alloy bridge. As the threads were good I cheated and just sprung open the upper rear frame loop out and onto the two ends of the stud. This now means to get the rail off I have to remove both the oil pipes the tool boxes top jampot fixing the tank and seat the foot brake arm to allow me to spring the top rear loop out of the way. Rather than do all this I am hoping to empty the oil and petrol tanks drop the bike on its side and remove the rear wheel. Makes sense to then drill out the stud and tap the boss as per Spriddler's bike. Seems the easiest solution.

If I remember right the stud is 5/16 diameter. Is there enough 'meat' to thread it 1/4 26 tpi BSC? If you don't run the die right down to the base of the stud - leave the thickness of the silencer bracket and washer - you will hang the silencer on a nearly full diameter bit with the nut (which does not carry the weight of the silencer) on the reduced part. Not ideal but a lot easier than pulling all to pieces. Hope this helps, Andy

The lack of a part number for a stud does suggest this is a permanent part of the frame Clive. I found a same size thread stripped on my 36 AJS when doing a check up, just before setting out for the Jampot rally nr Reding a few years ago. I found a die that made a thread, probably metric. Found a nut to fit and its still on the bike now. Save a lot of work if you are not too worried about having correct nut and thread. I did also pean punch the thread / nut. Un noticeable with a bit of muck on it.

If I were a bodger and couldn't get the rail off or be able drill from the inside after removing the wheel, I'd be tempted to cut off the stud, drill right through from the outside, tap the hole and use a bolt to secure the silencer bracket. If I was being fussy I'd braze a filler piece in the outer 'ole, lick of black Hammmerite and job's a good 'un. After all it only supports the silencer and pillion peg.

Me do a bodge mend Sprids? You know me too well. Might try the metric die on the stud first, I could not find a die amongst mine that would do the trick but I don't have metric ones. The new tin of Hammerite (black smooth) is already bought. A short journey down under prevents further work at present, I will report back when I get the job done. Thanks for the ideas.

Some really inspirational ideas suggested there. One of the many advantages of coming here.

Steven Surbey has just sent me a PM so as to avoid the Adverts Police. But I think it's useful info so I will share with others and not tell myself or him off!

"This stud was listed in some spares lists but not all and we stock it if you can't find a substitute to hand. Part number is 016768, £2.30 new. Same stud as used on the frame for the battery carrier/oil tank on pre-55 models."