Thread repair. Looking for best route.

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My customer laid his BMW motorcycle down and broke off his foot peg mounts. I welded them back on but in the process of chasing porosity got closer than I wanted to the swing arm pivot bolt in the middle. I did not go into the threads but must have got more warpage than I would have expected. Between that and the soft welded al when I tapped it out it was more wallowed than I would have liked. Unfortunately it's a super rare thread so there are no timeserts or helicoils or anything in the 24 x 1.25 pitch. My first thought was to solder in there to just add a little material. Found out quick normal solder and flux won't cut it. Adding a little material with the TIG is an unlikely prospect since the cast is so foamy and porus there is no such thing as a delicate procedure welding it. I added some JB weld then retapped it and it has held it's torque but when I talk to the customer I want to present them with some options since though I am fairly confidant in it there is still that question in the back of my head. I am still keen on the soldering option and it sounds like if I get the right flux and possibly solder that it would work. I like the idea of solder because of it's low temp and the fact that I am not looking for a lot of strength however I am open to brazing if it would be a better solution. Getting this piece hot enough especially without taking a lot of stuff off the bike is the biggest issue so lowest possible melting temp would be best. What are peoples thoughts? A pic of the area. The big hole in the middle is the one in question. Lincoln precision TIG 275Millermatic 140 MIG
Reply:Weld the hole up solid and then drill / tap to 24 x 1.25 .orRun a bolt all the way through and put a nut and washer on the back side.Lincoln SA200's... at least 15 - 20. They come and go. Growing partial to the "Short Hoods" in my old age. Last count on Short Hoods was 13 in possession.
Reply:Originally Posted by hobohiltonWeld the hole up solid and then drill / tap to 24 x 1.25 .orRun a bolt all the way through and put a nut and washer on the back side.
Reply:I have found aluminum soldering paste which looks like it could work but I have never done something like that or soldered in a application like this. Similar to brazing I would hope to tin the inner bore, hopefully one half first then tap then the other half so I could tap off the existing threads. I feel like something like silver solder would have enough strength and hardness to do it's job reinforcing threads. I have found a couple things like al brazing rod and durafix which look great but are higher temp which would make my life much harder.Lincoln precision TIG 275Millermatic 140 MIG
Reply:http://www.beemerboneyard.com/
Reply:You could use this. Butter it all up good and tighten it down......http://www.all-spec.com/products/Dev...-00/14415.htmlQuick, cheap and shame on the next guy who needs to remove it.Lincoln SA200's... at least 15 - 20. They come and go. Growing partial to the "Short Hoods" in my old age. Last count on Short Hoods was 13 in possession.
Reply:You could use this. Butter it all up good and tighten it down......http://www.all-spec.com/products/Dev...-00/14415.htmlQuick, cheap and shame on the next guy who needs to remove it.Lincoln SA200's... at least 15 - 20. They come and go. Growing partial to the "Short Hoods" in my old age. Last count on Short Hoods was 13 in possession.
Reply:Hi,Good call Hobo, The Devcon or 3M 5200 will do the trick.Jeff
Reply:Make a thread insert. Enlarge the hole and tap with a larger thread, say something like 30mm, and make a steel insert with the 24mm thread internally and the ~30mm thread on the outside to fit the new size hole. Or make a new swingarm axle with one size larger thread and enlarge the hole to fit that. If that thread would fail while driving and the axle starts to come out it may very well lead to a crash. I would absolutely not put my trust in some soft solder or JB weld when somebodys life will depend on it - it might hold torque standing still, but the loads while driving is quite diffrent so who knows what happens then?Usually I think most people on this forum is way to picky about how repairs on trailers or cars are made (although I can understand it, with liability being what it is in the US). For the first time I actually think they're not complaining enough about it. Break a car or trailer and most of the time the damages will only be material, break the suspension on a motorcycle on the highway and you'll probably end up with an injured or dead driver.
Reply:I like the insert idea, but make it as a nut with a shallow outer flange for ease of installation. Drive could be by pin spanner instead of wrench flats.Bore and tap the hole for the insert, good to go. Green Loctite the threads where the insert goes into the part.Easiest way would be to take some round stock, drill and tap the internal thread, then cut the external contours and thread on a lathe.This looks like the best way if you don't have a machine shop or don't want to pay one:http://www.beemerboneyard.com/