Is there any historic precedent for the use of dropped spindles on beam axles, instead of a dropped axle? If any photographic documentation exists I should surely like to see it. Dropped spindles seem on the face of it to have advantages from a structural viewpoint. I did some elementary calculations, assuming a vehicle mass of 3000lbs and an acceleration or deceleration of 1g, for normal forces on the kingpins and the resulting torque at the end of the axle: ±29" stock early Ford tyre: 6500lbs top; 8000lbs bottom; 1793lb.ft ±24" hot rod front tyre: 5250lbs top; 6750lbs bottom; 1477lb.ft ±24" tyre with 2½" dropped spindle: 4000lbs top; 5500lbs bottom; 1158lb.ftThis is equally true for lateral or longitudinal accelerations/decelerations. Simply reducing the diameter of the front tyre in the examples reduces the torque on the axle by 21% for any given acceleration/deceleration. This torque was never going to lead to axle failures anyway (assuming a good quality forged axle) but elastic strain on the more flexible ends of a heavily dropped axle might be greater than ideal. The more predictable caster and camber can be kept, the better. Substituting dropped spindles on a less severely dropped axle reduces the forces on the kingpin even further (torque 55% less than stock) and allows an axle with stiffer ends. It's probably splitting hairs unless we go to the taller front wheels a lot of people favour these days. Taller tyres mean higher hubs, and a more extreme amount of drop in the axle for a given ride height. If the tyres are any grippier than stock it might make for a wobbly/whippy front end. Severer dropped spindles would help a lot in these cases. There might also be advantages to setting up steering e.g. having the tie rod in a more convenient place, though I imagine that scrub radius might be tricky to design around. It might, of course, look all wrong to eyes accustomed to dropped axles: I'm not so sure, hence my keenness to see if it was done before.
I need a visual....in my mind it seems like there would be way more"leverage" if the spindle was above the kingpin? Got a pic or drawing of a dropped spindle?
The spindle assembly would obviously have to have a degree of rigidity designed in. My first instinct was also that the leverage happens at the hub, but given a rigid spindle assembly the position of the hub is immaterial. Everything happens at the kingpin. Or rather, there is more space in the spindle assembly to design rigidity in than in the end of the axle, especially in the fore-aft direction. I don't have any pics, as I've never seen it done.
See an upside down version on a 4010 john deere. Used to use those rambler bolt on spindles to make dropped trailer axles.
Cantilever would be one way to go. This part wouldn't work because the kpi is the wrong way: And it's huge. The kingpin is 1.5" in diameter. Though a cantilever design would need a heavier kingpin than stock Ford. Bolt-on spindles are common enough these days, on the back of front-drive cars. It's just a matter of matching up wheel bearings to the desired hubs.
Dang Ned, I feel sorry for ya. You must be confined in a very small room due to this Pandemic. I hope you recover soon. The Wizzard
I'm glad there's always someone else willing to do the Hard part so I can just stay in the Shop and Work.
I suspect that the only reason that they don't currently exist is demand, vs. production cost, and that the reason that they did not exist in the past was the difficulty of production, vs. demand/return. There are lift/lowering spindles for all manner of vehicles now, as the process is better, and cheaper, but we have fallen to a microscopic percentage of demand for such a thing. Especially so here. These would not be "traditional". Every angry old man would be shouting at you.
Matching wheel bearings is very dry research work but it's strangely satisfying. Since the end of WWII a vast array of vehicles from Buicks to Studebakers to BMWs to Ferraris have used the exact same front wheel bearings, i.e. the Timken SET6/SET2 combination. Timken have published very useful information, so I'm using their nomenclature though other manufacturers have their interchange equivalents. The inner bearing (SET6) has a 1¼" bore and an OD of 2.328", and the outer bearing (SET2) has a ¾" bore and an OD of 1.781". By contrast an extremely small number of front-drive vehicles have used these bearings on the rear wheels, and of these none have bolt-on spindles/stub axles. Moreover, the 1980s, when many manufacturers replaced rear-drive models with front-drive models, also saw the advent of bolt-on sealed, non-rebuildable hub/spindle assemblies. The new pattern is a hub rotating inside a tubular spindle which provides an easy way to mount an ABS sensor. These are of little use here, as the wheel bolt patterns are limited and often don't match common traditional-era bolt patterns, and to my mind their sealed, non-rebuildable nature is contrary to the spirit of traditional-era technology (we won't debate sealed-beam headlights again ) That leaves a narrow window from which to source bolt-on stub-axles. I've identified three possible sources of bolt-on stub-axles suitable for fabricated spindles, be they for beam axles or any other kind of front end. None use the SET6/SET2 combination but none will need more than one sleeve to fit a SET6/SET2 hub. 1. First and second generation Chrysler Minivan, up to 1995: The SET16 outer bearing has the same OD as a SET2 bearing, and a SET6 inner bearing can be used on a 0.0637"-thick sleeve. 2. Lots of Audis between 1978 and 2001: This takes a SET2 outer bearing. A SET6 inner bearing needs a 0.0541"-thick sleeve to fit. 3. Kia Rio, 2001-2005: This also takes a SET2 outer bearing, and will need a 0.0938"-thick sleeve to fit a SET6 inner bearing. While it is younger, the Kia is however a lighter car than the Chrysler Minivan or the Audis, and so its stub-axles are perhaps better suited to lighter builds. Early Ford outer wheel bearings have the same bore as a SET2. Early Ford hubs and bearings will fit on the Audi and Kia stub-axles with suitable sleeves inside the inner wheel bearings. Fitting them to the Mopar stub-axles would be a bit more complicated. Spindle lengths will differ. That information is not so readily available. It might be necessary to make up spacer rings. I think that might be some useful information right there.
Ned, early Chevy spindles were used on Ts to lower them back in the day. I also seem to remember AMC spindles that were 2 piece being used to adapt disc brakes. Definitely some interesting ideas there.
Funny, funny funny,, There was a new guy who only mentioned that he didn’t want drop spindles for his model A. Went way off the rails, pissed him off and he got butt hurt. here’s how to roughly use a ford spindle and amc stub. You can do disc brakes as well. We can do much better just with a little effort. Now here’s the Argo manufacturing spindles , an amc copy (almost) for the circle track guys. very nice high quality forged stuff, There’s a caliper bracket too, but I left it out because it’s confusing and cheesy. And here’s the spindle stub, available separately, $37.xx. It’s designed to take this rotor ( again for the circle track guys) not amc hub. Who the hell else is going to need an AMC spindle???? That rotor “hub” is Mustang 2. It’s all there for the tryout. Absolutely use a known good forged spindle. I used a willwood M2 hub and modified it slightly and used 02 Camaro slip on rotors on the Argo spindles. I also took 1959 MB 190sl stock spindles and made disc brakes with 1” drop spindles. The stubs were custom machined. This After we stuffed a big v8 into that little Mercedes. So I’m not afraid to do things that “can’t be done” Now when dropped spindles go on to any vehicle, it changes the scrub radius.
And guess what wheel bearings go onto AMC spindles? SET6/SET2 (except for '75-'78, which take the same SET17/SET16 as the early Chrysler Minivan.) So MGB splined knock-off hubs (for instance) are a direct fit, apart from possible spacers.
Not sure on that Ned but you might might do a few quick searches on Rock Auto to check. i say that because once you get it down you can find and compare things pretty fast on there. I have a buddy who owned a wrecking yard from the 80's up into around 2005 who lowered a number of rigs with the AMC spindles. Pretty much as 31Vicky with a hemi showed in the lead photo of post 16. Pretty damned crude at best and I doubt it would pass many safety inspections. On the other hand. a dropped axle is simple, looks fantastic on most rigs and done right doesn't compromise the integrity of the front suspension. For most it is just the deal of finding someone who can do it right and coming up with the money to pay them to do it.
My analysis suggests the opposite – provided the spindle design maintains the correct scrub radius. The shorter the distance between the kingpin bushes and the road, the better. The position of the hub is immaterial, as any moment between the kingpin and hub partially counteracts the moment between the hub and the road, leaving the moment between the road and the kingpin as the operative resultant.
Of course the spindles would need to be designed with greater beam strength than stock spindles. In practice I'd expect it to be a matter of some gusseting between the top kingpin boss and the back of the area where the stub axle attaches – clearly lacking in the AMC-early Ford hybrid spindles above.
Here's a quick 3D model; no structural calculations or any real detailing done. I used the Audi stub axle because I was able to find dimensions for it.
Lacking yes but easily added, Those things are so cavemanesq rough. I like the cad version. The diameters on the spindle are one thing and then the distance between them is another. Both need to be in the right places for suitable hub with correct offset.
The Jalopy Journal
