And in answer to your actual question. Yes welding it may cause it to break. Course that will all be dependent on the turns you make, amount of grip you have at any particular time, etc. Personally if it was me, I'd weld that and be on the lookout for the Sport axle. I would weld the front diff also, and get a hold of Phil also known as plh, and order some manual hubs ( manual hubs ) for the front so you can run that locked front axle. This should create quite the firestorm, welding diffs is not taken lightly in this forum. You seem to have one of the rare non-LSD equipped Gen 1 SWB, as I have not seen one yet. We have two in JY's around here, both have the LSD.