just got my Speedway 6"droped tube axle. for my 31 chevy pickup. it comes with no spring pads welded on. what i'm wondering is what degree of angle do i want to set it at for good everyday driving. THANKS Jay D.
You are going to get a hundred different suggestions. Only thing I’ll say is make sure it is checked at ride height. Btw, mine is 9 degrees. Somewhere between 3 and 10 is what you will probably hear.
I think he’s saying kingin angle is camber or I guess depending on the spindle the king pin angle vs the spindle snout angle is different from ford to Chevy etc but we all know your meaning the castor so I didn’t see any reason to be picky about what you called it.
King pin inclination is the angle that the king pins lean in at the top when viewed from the front of the vehicle. Caster is the angle the king pins lean back at when viewed from the side of the vehicle. To complete the nomenclature roundup camber is the angle the wheel leans in or out at the top relative to a flat road surface when viewed from the front. Positive camber leans out, negative leans in.
Another question, should i have the wheels and tires on. its going to be suspension wise about an 1 1/2 lower in the front then i'm going to be a couple sizes smaller with the tires in the front. should i tire it all up and then set the castor, looking at around 7-10 deg. i was originally thinking that the frame should be level BUT when the front is lowered thats going to take way from the set deg's. ??? maybe i should stop thinking. Jay D.
Well Mart , that’s the correct definition , of my question . I’m thinking he is trying to determine caster angle . He wasn’t sure of the correct term to use . Caster needs to be 5-10 * positive . Easy way to define if you have it correct or not , remember spinning the fork and front wheel on your bicycle , backwards and try riding it , that’s negative caster . Thanks , Mart , you defined it simple
Remember the caster angle is relative to the road surface rather than the vehicle. So correct tire sizes fitted front and rear, ride height set front and rear and full vehicle weight. Back in the day dumping the front and putting long shackles on (raising) the rear would reduce the caster angle and make the car twitchy and not wanting to self center on the steering.
^^^^ Back in the day most cars did not have much positive caster (my Buicks 1 degree) so they would steer easier on poor roads. As the caster angle increases, the front steering "centers" back better, but slow speed steering effort is harder. 5-7 degrees is a good compromise, and up to 10 degrees with lighter cars and smaller tires.
Easiest way is set the frame to height. Any suspension I set up or build is always done to ride height of the frame. Once the frame is set to height you can mount any suspension bracketry to match the height your after. ..
When you're all done, check it again. 7 is a lot, but okay. But everything changes when you have the vehicle done -- tires on, engine in, etc. Check it again.
Please tell us that you didn't waste money on one of those Speedway trailer axles pretending to be a dropped axle. Kingpin inclination should be right at 7 degrees. The GM heritage center vehicle information kit showed numbers but no diagram Second image matches my 48 and shows the king pin inclinaton third image shows the specs for a 49 with some explainaton diagrams. Desired caster is going to be around 3 degrees positive. Parallell leaf front ends don't seem to need as much caster as Fords do. Caster on a rig with an axle still comes down to how it feels to the driver and how it tracks.
YEP, its from Speedway, but it has spindles on it. a trailer wouldn't handle very good with it . Jay D.
U concerned with spring pads location so forget front weight. Mount the axle in some kind of bracket/holder at 7 degree to flat ground then weld spring pad parallel to ground. If still concerned tack weld until almost done with fully build truck, check caster & spring mount, final weld.
The last thing I do when setting up a solid front axle is to set the castor. Once everything is fully loaded, and the tires and wheels are sitting on the ground, then the spring plates can be welded, or the castor set by adjustment. I use 5-7 degrees most of the time, but on very short wheelbase cars I use more. My 89" Austin is almost 11 degrees, and drives great.
AmishMike, Thats my plan get the plates on as close as i can and tack. then put put it all together and then a final check and weld. THANKS Jay D.
I just went through this in the spring. I purchased a car with a straight axle front end and the steering wheel would only crank about half way through the cycle on the ground. When I jacked it up it would turn completely through the cycle stop to stop. With the car setting on the ground I measured 10 degrees positive caster so i purchased 5 degree shims and PRESTO, it steers great now at 5 deg. pos.
Well, I wonder about this. The shackles change position when the weight of the front end comes down so the tires are on the ground. Wouldn’t that also change the castor as well? I’ll be doing the same thing with a dropped tube axle in the next few months, that’s why I’m asking the question.
Remember “bad six” working on old Chevy with parallel front leaf springs. Fords with cross spring & radius rods different. Radius rods with adjustment easier other wise gets tough. May want to adjust transverse spring mount to avoid spring twist with a wedge or mount of cross member. If split wishbone & tire rake gets real complicated for proper caster on Ford. My experience is with Jeep’s like Chevy changing front axle mount & springs. Recommend tack spring pad & shackle mount until all weight on car. Spring pad probably ok but May want to adjust shackle mount to get at preferred 45 degree angle. Jeep’s get real complicated to keep front drive axle at proper angle but hot rods do not need to worry about that ( smile).
depending on how your shackles are mounted, how your spring flexes, how much your front suspension is compressed, and the final tire/wheel rake of the car, it WILL matter to how you mount the pad. I always try to ***emble as much of the car (with whatever style of suspension) so that it is sitting as close to its final weight and stance as possible, and then measure the angles. much like rearends and pinion angle, things change once weight/force is applied. I would clamp or tack it together, and put as many other pieces together before I finalized the caster angle. And for what its worth, my T has 10 degrees on a early ford style setup. drives great.
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