Junk parts.

[Will L.]

I can promise you:
how it would not tighten down normally, the seat is toast.

Welding it up and re cutting it means re temper it. The amount of labor involved shoots the cost way past doing it. I don’t know many guys that understand how to do it right that would because of the liability. This is WAY more dangerous than driving around with half the brakes not working.

On the tapered seat- you have to understand it holds incredible force. That little nut with the cotter pin just keeps a proper fit taper from jarring loose. Think about when you take one apart that is good- take off the nut then how hard is it to pop apart? That isn’t because it is old or rusted. That’s because the wedged force holding them together.

The nut shears off whenever the taper is toasted. Think about how much easier and cheaper it would be if the manufacturer could use a bolt, washer and nut. But they don’t because the force applied is insane. Adding washers or welding the nut to the ball joint is not going to hold. Might welding it for a hour, day, week, month? Who knows? All depends how lucky you are.

My suggestion would be sit down with email/ phone getting ahold of junkyards in Southern California, Nevada, Arizona because they might have some not rusted if new is not available.

 

[Husker6.5]

And my two cents from over 50 years of wrenching, on just about anything driveable - from a Honda Trail 70 motorcycle to an M60A3 combat tank, and just about everything in between including just about all manufacturers - PROPER SPECIFIED TORQUE ON ALL FASTENERS IS CRITICAL @Stoney, ESPECIALLY on tapered, interference-fit fasteners such as ball joint studs or tie rod end studs!

NOT just "it feels tight enough 'arm strongium' torque" - but the actual torque specification achieved using a QUALITY (ie: Snap-On, Mac, pre-2000 Craftsman, S-K, Proto and not Harbor Freight, OTC, or unbranded cheap Chinesium), CALIBRATED (that is it has been tested for its actual torque reading vs. what it is set to, by a calibrated bench testing device) torque wrench! The best, most accurate type of torque wrench is the breakaway or "click" style where you rotate the handle to a value on a scale and then feel/hear a "click" in the handle when that torque is reached on a fastener. Beam-type, with a pointer and a scale on the handle, are just too prone to inaccuracy due to several factors. The newest digital ones are also highly accurate (make sure they're reputable mfr's, not Chinesium knock-offs), but very pricey. A SMALL dab of anti-seize on the stud threads before running the nut down does two things - it ensures some lubrication to ensure accurate torque on the nut and it will ease disassembly in another 100K miles when it's time to replace the ball joint again, if needed.

Also, as mentioned above, BOTH the tapered stud and the tapered bore must be absolutely clean, shiny metal. If need be with the bore hole in the spindle, take a strip of Electro-Cut, emory cloth or 240 grit sandpaper, curl it around your finger and use it to clean up any rusty/corroded areas inside (a clean rifle chamber brush, like from an M16 or M60 cleaning kit, or shotgun bore brush, works great for this, too) and then spray clean with brake cleaner and let dry before assembling WITHOUT any lubricant in the bore or on the stud.

Also, UNLESS the factory, assembly line part used a Nylock (nylon insert) lock nut - DO NOT USE a replacement part that does! Also, ALWAYS use a NEW cotter pin with a castle nut and if you've tightened the nut to torque and the notch in the castle nut doesn't line up with the hole in the stud for the pin to slide through, DO NOT "back off" the nut slightly, ALWAYS tighten it slightly more until they line up correctly!

And lastly, IMHO, anything from AutoZone that is not an authorized name brand such as Moog, AC Delco, Bendix, Wagner, Raybestos, etc., is total crap junk. Knowing who the manufacturers are for those generic "house brand" parts are, I wouldn't be surprised if AutoZone's are the seconds or rejects that Advanced and O'Reilly's didn't want for their generic house brands! As for any suspension/steering pieces like ball joints, tie rod ends, idler arms, etc., I only trust Moog, the heavy duty Mevotech or OEM (like genuine AC Delco, FOMOCO, or Mopar) or OEM suppliers. Too much on the line for using cheap, crap parts in such critical places.

And very lastly, I've never experienced or heard of a castle nut just "breaking in half" before - that had to be some seriously low quality, cheap steel that wasn't even Grade 2 quality as opposed to the Grade 5 or 8 that is standard for such fasteners, to "break in half". What you've described in the damage to the tapered bore in the spindle, and your photo hints at, is a castle nut not properly torqued working loose (was a NEW cotter pin properly installed, there's only one way to correctly do so, to retain the castle nut and keep it from vibrating loose/off the stud) and the stud then began moving around in the bore of the spindle and as it moved/vibrated more, the castle nut backed off the stud and fell off, then the ball joint stud, under the additional pressure from the coil spring, fell out of the knuckle. Prior to that, as everything was loosening up and getting play in it, you should have been able to hear it clunking around or felt the abnormal play through the steering before the catastrophic failure.

 

[GM Guy]

chain auto parts store, store brand stuff is garbage id only put on a winter beater thats final stop is the scrap yard, and even that is debatable.

Put quality on, its cheaper in the long run.