Whether youre preparing them for plating or just want to clean them up before painting, its a fairly common practice to grind down the weld thats near the front of an early Ford front wishbone, where the forged fork is joined to the formed tube. My gurus tell me that when the wishbones are used conventionally and as long as you dont remove too much metal, grinding this weld is generally considered safe. (Youll want to make sure not to grind down the weld that runs down the length of the tube, though, because there have been cases where the tubes have split open.) Over the years, as a way of lowering the front end, some cars have been built with the spring perches attached to the tubes of the wishbones, behind the weld. When this is done, the wishbones are subjected to load-bearing and shearing stresses that they werent designed for. Although I have several original 32 front wishbones here (some split, some not, for various projects), Ive never had to cut any of them at the weld at the front (to dial in the caster, or for any other reason). Ive been told that when these wishbones were made, the fork and the tube were simply butted up and welded, with no internal reinforcement. Can anyone post pictures of a 32 or 33-34 Ford wishbone thats been cut open at the front? Dave http://www.roadsters.com/
I don't have any pictures but I'm pretty sure it's not a butt weld. The one I cut apart (over 30 years ago) had the casting extending into the tube about a 1/4" or so. It was done just like a driveshaft. If it's critical, I can measure through the lightening holes to tell how far it goes in. Right now it's buried under some household junk. I can't get an acurate measurement.
Dave- I'd say that neither one of the welds being ground down ,would be as crucial to it's strength as the fact that the chrome plating of a wishbone would weaken it thru imbrittlement. I do believe that if a person mounts a spring perch on one- there should be a "failsafe" for it to catch the load in case of either the radius rod or the perch mount failing.
Ahhhhh....yes it WOULD seem that quite a bit of force would be applied to that critical joint. The welded joint would want to crack on the bottom and allow the axle to twist. BUT...ALL the wishbones FORD built with the spring mounted in FRONT of the axle have exactly the same twisting forces acting on them...just that they want to split on top! If your still concerned about the bones snapping, (And I agree, its good to be concerned about potential safety issues!) just add small gussets from the forged steel end back over the wishbone tube and you would have a stronger setup than any stock configuration. You COULD even notch the tube and allow the gusset to extend down into the bone to a point where the perch bolt/spring mount would actually pass thru it, as well as the tube. The gusset could even extend as far back as the welded bung(!) for the chassis tierod end if you were REALLY concerned for the strength. Once it was welded into the cut slot and ground you would never know it was there anyway.
I just cut up a couple of wishbones a couple nights ago. A model A (I think) to use the front casting, and a '36 for the longer bones. The model a ends didn't really have any internal shoulder to them, just some casting flash it looked like that extended into the tube a little, not really enough material there to add strength. Heres a picture I took, although you can't really see very well.
casting of A32 wish bone extends about 1/4inch maybe a little more,go to rollin bones site through hop up, all their front springs are mounted this way...
The flaw with all these arguments is that rodders have been splitting, chroming, welding perches to, and generally abusing wishbones for 60+ years. I have never, ever heard of one failing, and I've seen some pretty weird things done to them. There was a thread on the Hamb recently about being over-technical, and in my opinion this falls into that category. Hell, the Hamb is part of the JALOPY Journal in case everyone's forgotten.
This is an old post. I'll agree with you that lots of folks get way to technical and give lots of shitty advice about which they know nothing...but I have seen modified split wishbones break. It's happened to me twice (both sides, and not bones I had worked on...but had bought that way). I had to drive back from Utah in '99 with one splinted back together using an angle iron, hose claps, duct tape and some wire rope with turnbuckles. And I'm sure others have broken too...there's plenty of bad workmanship out there on the roads.
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