Did you anneal and normalize the steering arm after welding on it? I'd be a little concerned about possibly creating stress risers where the welding was done unless the whole piece was heated cherry red and allowed to cool slowly. It would be a real disaster if that piece broke unexpectedly on one of those twisty roads.
Jerry
Hi Jerry,
Thanks for the comments. From a spark and file test (not too scientific I know, but the available technology in my shop
) I reckoned that the arm was probably AISI 1040 or something very similar (it would be called EN8 Steel in the UK) and was clearly in the annealed state. I did three or four passes on each side of the steering arm with the TIG torch to build up metal for the the new boss, so the arm got a real heat soak. During the welding I had to stop a few times (with the Argon shielding gas still flowing) as the piece would have overheated otherwise. After leaving the arm for a slow cool, and using a file to square up my welds and round off the parent metal after sawing off the original boss and hole, I’m confident that the steering arm is still in the annealed state, so I didn’t carry out any further heat treatment —there is more material around the tapered hole now than as supplied.
Doesn't lengthening that steering arm place the drag link at an odd angle front to back? I know that the drag link needs to be parallel with the road to prevent bump steer, but I am wondering if a drag link that is not aligned perpendicular to the front axle would cause a steering issue such as bump steer.
I hope not, because I like the mod. I have the same CPP setup on my '49 and I would like to have it be a tight turning truck similar to the original steering.
I would probably have a longer arm machined from scratch rather than welded, as I have trust issues in my own welding and that of most welders. I cannot fathom the "exciting" ride it would be should that arm snap off.
Carl
Hi Carl,
To increase the steering lock with the Saginaw box, either the Pitman arm needs to be lengthened, or the (mounted at the spindle) steering arm’s length needs to be shortened. On the early trucks, lengthening the kit supplied Pitman arm isn’t an option because the wheel/tyre would collide with the Pitman arm ball joint before full right hand lock is achieved. The shortening was done by increasing the side-to-side dimension of the steering arm by TIG weld build up. The new tapered hole is bored through the arm’s original metal —the weld just adds extra material/strength.
This modification leaves the “side on” angle of the drag link unchanged, this is important for bump steer as you say. The angle which is critical with this modification is the angle between the drag link and the steering arm (viewed from overhead or underneath) in full left hand lock. Here the drag link is “pulling” on the steering arm; if the steering arm was shortened too much, the drag link and steering arm would make a straight line pointing through the king pin, with the risk of the steering kicking “over centre”. I modelled the new hole position before I started work to be sure that there is still a working angle at full lock.
As a general point, I am really keen that my steering wheel keeps it's connection with what's going on with the front wheels -the alternative could spoil my whole day as you have both kindly mentioned.
. However, in the first of the two pictures I linked to, the hole at the end which is discoloured is the one that steering arm came with. The shiny hole in the steering arm is the one I have drilled and taper bored.