ive just had my rods machined down and re threaded by an old guru,i can get more done for 100 bucks if u send em to me.
pm if u interested il get pics up of his work when i get home on the weekend maybe.

Do you know if your man turned the threads or did he use a die nut to extend the thread length?

Interesting question. The factory rolled the treads. Its worth noting that the body of the shaft goes under size behind the rolled threaded area.
I too, years ago used a die to cut additional tread, but in the end the rod failed [lucky for me it was at low speed] and the wheel smacked into the inner wheel well. If my memory is correct, case herdening is used. In my case the rod may have coped a hit over time and the structure had fractured as the evidence of the surface of the two pieces I have is that the crack went approximately 1/3 through the cross section of the shaft and remaining 2/3 is all bumpy indicating a snap like condition when it finally let go.

When this happed to me it highlighted that the castor rod is a key component to maintaining steering control, when it let go I was simply a passenger. The integrity of this part is paramount.

Spot on Benny.

If the threads are die cut the tension rod will eventually crack and fail if it is put through enough tension cycles. Its not a matter of if this will happen but when. The thread quality will not be good enough.
Heavy braking loads on patched surfaces for example can introduce high cyclic loads which will result in a failure.

If the threads are machined by a competent operator on a lathe using a thread cutting tool which results in the correct root radius and surface finish on the threads it MAY be OK.

Be very careful.

Would it be safe to weld cast iron castor rods ?

Im trying to adapt adjustable s13 rods but I need to some how put a straight threaded end on the front of it to mount up to the bush mount/hole

I had some done in the lathe, problem was most castor rods are not that straight and the thread tends to thin on one side as you get into the bendage of the rod.

Had one break resulting in an accident while rallying quite soon after putting them in, but replaced it with another (and fixed a bunch of damage)and have done about 20 rallies with no more failures

Mine failed after about 12000 km's of service. It was cracked for quite a while and finally broke under brakes. I have since reverted to a collar type method of adjusable castor rods. The collar is made from a piece of stock bar tapped to the same metric pitch as the original CR. The castor rod then screws in or out of this collar to achieve the desired castor angle.




Apologies to greendog, didn't mean to hyjack your thread.....

"and the structure had fractured as the evidence of the surface of the two pieces I have is that the crack went approximately 1/3 through the cross section of the shaft and remaining 2/3 is all bumpy indicating a snap like condition when it finally let go"

Classic fatigue failure. A small crack or nick in the surface grows under cyclic load, little by little until the section is too small and you have sudden brittle failure, bang. If the surface was still clean you'd see what are called beach marks, little ripples eminating from the original crack (although they can be hard to see).

What everyone's described indicates that the castor rods are loaded near the material's endurance limit and should probably not be fiddled with. Die cut threads tend to tear the surface and leave lots of potential cracks, or so called stress concentrators. Rolled threads are much stronger and fatigue resistant.

thanks for the warning guys as i was going to put them them this weekend.rods were straightend before being machined,and yes the threads were cut with a die? might call him and see if he can turn some threads on the lathe.thanks

NoLife, I like the purple anodized camber compensation spacers.