Sinbox down..

[rallyvan]

Does anyone know if the castleated nuts are just working loose or whether the nuts are cracking and failing? Wondering if the slots in the castleated nuts don't have any radius at the bottom slot (when compared to previous replacement units) and this is what is causing the failure. The lack of radius leading to cracks around the base of the slot area. When I re-assembly my van I think I'll see if I can get some from a the local engineering supply house hopefully they will be a bit better quality.
I use to help a bloke with an EL Falcon rally car that had a bad habbit of braking Watts linkage pins in the rear end. This was usually induced by giving the odd bank a tap at speed. We found the standard Ford pins had a square shoulder at the base of of the threads which lead to a stress riser. We had some new pins made with radius at the base of all the threads and the failure rate decreased dramaticly.
You have to be greatful that the failure happened at low speed so the damage was minimal. If the ball joints were replaced during the resto process it might be worth getting in contact with the supplier and letting them know. They might of had a bad batch of nuts.
Anthony

[Nigelk777]

Just a tip ... avoid nylocs on ball joints if you can. I used them on one of my cars and the ball joints just spun when I tried to undo them. No amount of cajoling would get them off so out came the angry grinder to cut the nuts in half ... I've now used new (ordinary) nuts and simply drilled a hole through them and then used a good split pin. Nige

[James]

Just a tip ... avoid nylocs on ball joints if you can. I used them on one of my cars and the ball joints just spun when I tried to undo them. No amount of cajoling would get them off so out came the angry grinder to cut the nuts in half ... I've now used new (ordinary) nuts and simply drilled a hole through them and then used a good split pin. Nige

If you've drilled your own hole through the nut (and ball joint) you may have weakened it. Another way would be to use two nuts and lock together.

[Defuser]

Same thing happened to me many years ago In my HX Sandman. Castle nut completely stripped off to the point of being smooth where the thread should have been. Had driven this van to just about everywhere, Melbourne to Brissy numerous times, Hotham every weekend during winter and it decided to "Let Go" reversing out of car park at South Land shopping centre HA!. A good mechanic friend of mine was at a loss at what caused it to happen. The van had had a pretty tough life with a few front end bingles from previous owners. Found that the sub chassis had a Crack that had gone unnoticed and I put it down to that. When thinking of all the places I'd been that it could've happened really freaked my out a bit.

[ozbox]

it doesnt just happen to holdens..similar lower control arm arrangements in the pontiac but bigger ball joints..this is our 71 t/a and this happened at 110kmh on a narrow rd out the back of the hunter valley..same thing ..stripped the nut...:knockout:

[jennie285]

Does anyone know if the castleated nuts are just working loose or whether the nuts are cracking and failing? Wondering if the slots in the castleated nuts don't have any radius at the bottom slot (when compared to previous replacement units) and this is what is causing the failure.
You have to be greatful that the failure happened at low speed so the damage was minimal. If the ball joints were replaced during the resto process it might be worth getting in contact with the supplier and letting them know. They might of had a bad batch of nuts.
Anthony

Rodney's brother did all the work, he is the service manager at the local ford dealership...he is at a loss as why it happened...Rodney never found the nut he did have a look for it to see if it was stripped....but the otherside had a split pin in it and was in place, so maybe that broke...mystery....