I am very curious what Brent has to say about this. I am also wondering how the area where the king pin bushings mount gets thin? This area really shouldn't wear, unless the bushings wear out.
Red
Thank you Red. I actually spoke with Joe by telephone last Wednesday morning on my way to a Model-T tour in Maryland.
In a nutshell, good spindles are indeed getting harder to find. I was at an A/T swap meet a month or so ago, and I only saw three A spindles and none of them were any better than what I already had. This is not to say there weren't some that I missed, but I definitely didn't see them. Folks need to remember that just because an item is at a swap meet -or for sale in the classifieds, it doesn't mean it is a good one. More often than not, the reason it is being sold is because it had an issue in its past and was replaced with a better quality piece. Otherwise it would likely still be connected to a front axle.
While Joe does not possess the equipment, he did take a machine shop class years ago so he has the basic understanding in how I was explaining to him to repair what he had. I do think what has changed is two-fold. It used to be that many restorers had access to machining equipment at work, -or they might have a small shop at home. Those days are about gone, -and seemingly no one has a friend who has access to nor the ability to help restore one either.
Nonetheless, here is how I explained to Joe on the phone how we would restore one. If the threads on the end are damaged or worn, they can be repaired by a couple of methods. To begin with, spin the spindle between centers on a lathe and use the steering arm hole to 'dog it' to the chuck. Often times, the threads can be rethreaded to a 18mm x 1.5 nut size from a 19mm (¾") size which corrects the worn thread situation. Another alternative is to TIG weld lightly around the perimeter of the threads just to add filler rod. Since most of these are rolled threads (instead of cut threads), then there is already material there to work with. Basically all I do is just add enough heat to wash the metal around where it can be re-threaded with a single-point threading tool. This does not compromise the forging nor weaken it enough to create any safety issue.
If the top or bottom Spindle Bolt bushing area has been damaged, then a spindle bolt (king Pin) with some shim stock can be clamped into the hole and used to indicate from to find the centerline. Usually the area is only worn on one side and you will generally have at least 180° of original machined surface area to reference from. Just clamp the spindle into a vise chuck on the Mill, and then use a boring head to clean-up the hole to make it round. Then use a lathe to make an oversized bushing out of bronze to fit the new sized hole.
As far as worn bearing race surfaces, you can use a knurling tool, -or even layout a grid pattern onto the circumference of the race area using a Sharpie marker, -and then use centering punch on each dot to raise the surface area. Next, spin the spindle in the lathe between centers to machine the raised or knurled areas of the race to match the ID of the bearing. I have also machined the race areas slightly undersized and installed a hardened wear sleeve (stainless band) by shrinking it on. I have not done this on a Model-A spindle but I have done this on an 1927 Essex and on a '09 Oakland with success. On the Oakland, it originally had ball bearings and I converted it too tapered bearings.
So the bottom line is, things like this can be restored -or made serviceable again but you must be willing to be creative and use resources available to you.
