Cracked swing arm

ok , get a sollid metal bush and put it in place of the bearing , you can then get it welded , this should stop 95% of distortion caused by the tig welder.alloy never distorts as badly as steel, i don't think that you will have any problems.

regards

scrap

Might I add,

You need two bushings to replace the bearings on both sides of the swingarm, with a center bore that has a snug fit on the swing arm axle. The bushings that you will put in place of the bearings should also have a close fit, but not with interference fit like a bearing other wise the aluminum will expand when it is welded and you will loose the interference fit with the bearings and they not stay where they are supposed to.

You could use the stock bearings and bushings for this, but, they will have to be replaced after the weld job.

Another thing I would do would be to make a crush bushing to emulate the center cases so that you can tighten the swing are axle nuts onto the bushings in the bearing area's and it will be supported between the two halves of the swing arm.

The swing arm axle through the bushings will make sure that the side being welded does not twist or turn in relationship with the center line which is a distinct possibility since that whole area is going to get very hot when it is welded, and any stresses that are present will be released.

Also as you may or may not know, that crack will have to be ground out into a V configuration to permit the proper welding of it.

It will also need to be SUPER clean. Once you have cleaned it thoroughly inside and out with contact cleaner, use a propane torch to heat it up to where it is hot to the touch, play the flame back and forth across the area, do not hold it on the aluminum for any length of time, up to maybe two hundred degree's or less, and clean it again. This will help remove any grease that maybe trapped in the pores of the metal. You will notice that this is going to get that whole side of the swing arm hot, as aluminum is one of the best thermoconductors.

It also appears to me from the photo that the weld above the pivot area that comes up from the inside in the lower linkage attachment area has a crack along the side that is spreading into the box tubing as well.