Any trick to getting the caster set on a 31 coupe w/ split 32' bones and speedway brackets.....everytime one side is the right caster the other is a little off....any help would be great?
Don't know if this will help your situation but the old time front end shop here used to heat and bend the axle to get the difference out of an I-beam. they used to do it while the axle was mounted on the car. Frank
I think the old beam axles were bent to change camber not caster. Maybe you could twist the beam for caster. Caster is the inclination of the kingpin, usually with the top toward the back. This setting makes the wheels return to straight ahead after a turn. More caster makes the steering wheel harder to turn. Watch a car with a lot of caster as the driver turns the wheel with the car stopped. The body actually rises as the wheels turn to the side. How is the caster adjusted with your split bones? Big threaded tierod ends? Sounds like the brackets are not in line with each other.
I was always under the understanding that a straight axle worked best with negative caster (top of the kingpin leaning forward from centerline), I believe it was 9 degrees negative...it would still give you mega good steering, reduce the steering dance at highway speed, and lessen the rise and fall when you're steering with the car stopped...maybe I could be wrong, but I'm pretty sure that's the old hop-up setup...
With the car/frame at ride height, clamp ONE wishbone bracket in place. Now measure your caster at the kingpin on the axle, first one side then the other. Is there a difference? If not, then you will have to modify the wishbone at the axle end in order to make them equal. If there IS a difference at the axle with only one wishbone mounted, then you have a bent or twisted axle. By the way, when doing this, I think that it would be a good idea to remove the wishbone that would be hanging free. The weight of the bone and bracket could skew the caster reading a bit due to the weight wanting to twist the axle. Shoot for 6-8 degrees POSITIVE caster (top of the kingpin angled back toward the rear of the car). You NEVER want negative caster. Chris
Thats the type of ****ed up advice you would read over on the Playskool Rods board. Dont need to p*** along bad info like that here.
There's an article in the Tech O Matic about dealing with caster and chamber problems on "I" beam axles. Check it out it helped me out. Also, NEVER run with Negative caster unless you like changing lanes often and unpredictably. Negative caster will seriously screw your stability.
More than likely your wishbone is "off" and not the axle. Like someone suggested, pop one side off and check both sides' caster. When you unbolt one wishbone... does it spring up or down? It shouldn't. Sam.
I have my A model sedan's '34 axle set at 9 deg. positive. I was shooting for 6-8 pos. but with at ride hight, and tire rake it came out 9deg positive. It steers very well and tracks straight. When I build a ch***is, the tie rod end brackets,from the bones to the frame is set after,the drivetrain is in, and the wheels and tires you are going to use are installed,and sitting on all fours, fully loaded,with driver/p***enger/fluids etc. Then all should be well.I believe a half a degree plus or minus either side would be tolerable. Sparky
I meant axle--but you do need to find out if bones are both pointed the same way! If bones do differ, then you need to figure out if bones are at fault or if axle is bent/twisted between the perches or something. Bones gotta be right, then the outer ends of axles get bent as needed to set C&C and get them to same angle.
A good way to clarify many axle issues is to clamp a piece of round stock into each of the 4 holes and sight along them. Perfectly fitted bars would be nice, but you should be able to do the job with whatever **** steel rod home depot has if each piece is clamped or wedged the same way into its hole, done so the rod follows a wall of the hole. No normal human being actually wants to remove Ford perch bolts, so try sighting from rods in the spindle holes to the protruding bolts...spindles are easy to drop off, even leaving brakes hooked up to hoses. Obviously, this is a job that would be easiest earlier in the build... You can also compare angles from the front fairly well, especially with long rods. If you improvise bending rather than going to a truck shop--I'm envisioning a long bar ening in some sort of wrench here--you can watch the rods to see how far you are moving things. Dunno if this is a practical approach, but I'm keeping my eyes open at the junkyard for suitable potential levers. You'll need to bend considerably beyond proper angle to allow for spring back. Ford did this with hydraulic jacks hooked to a complicated array of connectors and levers.
You definitely want positive caster; negative will cause road walk and a high angle will cause a hell of a shimmy on every bump. But it will back up great! IF the axle has a twist, it can be taken out without heat. As Bruce said, some notched levers (18" long), out of heavy flat stock (1") can be cut and the notch dropped over the axle, one lever pointing forward and one to the rear. Block up the rear one and push up on the front one to twist that end of the axle to the rear (+). A small bottle jack is all you need. The further they are spread apart, the easier the force required to make the correction. Use a magnetic angle finder to track the movement. As you will see, there is some spring back, so push past the angle you need. Oh yeah, put a small piece of flat stock (1/8") between the "force" side of the notch and the beam so you don't scar the edge. Also loosen the u-bolts, since the spring will want to twist. Or you can save yourself the trouble and find a shop that can align twin I-beam Ford trucks. Like us, they will have some special small tooling that makes it a snap. Might be worth the effort as a loaner tool, but not for one time use. Well, you asked what time it is, and I've told you how to build a watch. Film at 11:00.
Yes, Positive Caster, and it should be at ride height. The reason you have negative caster is because your frame was designed to have the same size tires on it. Same size tires = the frame is straight and parallel to the ground. When you put little tires in front it tips the front cross member forward causing NEGATIVE caster. There are two ways to correct this: 1. Remove front cross member and reweld it with 6-8 degree positive caster. 2. Buy and "adjustable spring perch" this allow you to tip the spring back. With 4 link it is just a matter of adjusting the upper and lower bars, with split wishbones you will have to bend the trail arm near the axle to tip the axle back. Buying adjustable spring perches is the easiest way but be ware you are depending on that tiny bolt holding up your car. That is the only part I do not care for. If it was me I would reweld the cross member in. Go to: http://www.hotrodheaven.com/tech/ch***is/rideheight.htm for ride height Here is a page that might also help you. http://www.hotrodheaven.com/tech/ch***is/ch***is4.htm#ride height D. Oshiro
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