Steering arms

[Dan Case]

When the steering arms were designed for Cobras CS 2030 (prototype rack and pinion steering car in RHD) and then CSX2126 (first production rack and pinion steering car in LHD that was the prototype for Ford electrical and cooling system components) onward, they were for street Cobras with 5.5” wide wire wheels and narrow widths of treads for standard and optional tires made with relatively hard compound(s) tires.

All early racing Cobras started off as street car chassis. I do not believe that the steering arms, forged in a straight ahead pattern for rack and pinion steering cars, and tie rod ends had any clearance problems as long as 6” wide magnesium sprint car wheels (a.k.a. kidney bean wheels or in the 1960s sometimes called coin slot wheels) made by Halibrand Engineering were used.

As soon as Shelby American started using any pattern of magnesium wheels made by Halibrand in 6.5” width an interference with tie rod ends and insides of front wheels cropped up. The amount of interference depended on the exact wheel casting pattern used (there were several in the slotted hole sprint wheels and six spoke sprint wheel designs) and how each batch of wheels was machined. Not every version of 6.5” six spoke (a.k.a. called FIA wheels even though they were used in all forms of racing Cobra participated in and the only version made with the F.I.A. in mind was the 8.5” inch rears where 8.5” rear wheels was allowed). I have no idea how many different 1963-65 casting patterns Ted Halibrand’s company had for the 6.5” wide six spoke wheels but I test fit five (5) different versions of factory racing wheel in 6.5” width on our red car one Saturday and every version had a different back spacing and every one had a slightly different amount of tie rod end clearance. I think that I have figured out a possible reason for so many versions of six spoke 6.5” wheels was perhaps that the designs and the sizes of front brake calipers in Cobras were changed a few times. Example: I have a pair of front wheels used in racing on CSX2009 decades ago and they will not clear the stock front brake calipers of cars CSX2165 and later without some kind of modification to something. I suspect that each time Cobra front brake caliper designs were changed Halibrand had to come up with a new pattern and machining patterns to make front wheels to fit. It was not until the 1965 version of the six spoke front wheel that new wheels worked with any Cobra’s front brake calipers including the large racing aluminum ones allowed in experimental or modified classes or in F.I.A. events.

For early rack and pinion steering Cobras, in all 6.5” wide front magnesium wheel cases it seems Shelby American heated steering arms and added bends to them to clear the back sides of magnesium wheels while they had new chassis partially dismantled for conversion into race cars. I believe but have no proof that A.C. modified the steering arms for the chassis specially ordered as race cars starting with the wide rear wings (A.C. Cars description, a.k.a. in later years cut back door cars) cars.

Enter what we call 427 Cobras. When the CSX30xx chassis were built at A.C. they had steering arms bent into gentle curves very much like that last racing Cobras. The first wheels for CSX30xx cars were left over 1965 type six spoke pattern wheels in 6.5” width. Soon the COBRA II 7.5” wide front wheels became available and then a clearance problem apparently cropped up. If you see pictures of an unrestored as built CSX30xx car with 7.5” COBRA II front wheels the rubber dust boots of the AP Lockheed tie rod ends are probably being distorted and rubbed by the magnesium wheels. The fix at some point for a retro rework for CSX30xx cars was to bend the arms some more.

Somewhere in the CSX3101-CSX3200 contract, and perhaps from the start but I do not know, A.C. put more significant bends in the steering arms and that created a better gap between steering tie rod ends and backs of 7.5” wide front wheels.

Very few "Cobra" related subjects are simple ones.

And then there were things that owners did post production to adapt all kinds of magnesium wheels in all kinds of widths up to 8.5" (that I have seen, perhaps wider) to the fronts of Cobras and 427 Cobras. I have seen seriously modified steering arms.