Wishbone/Caster help needed ASAP!

I've been working on my Dubble A for most of today, and ran into an issue or potential problem I need some advice and/or help with solving.

Okay, here's what I'm working with. I just hung the stock model A split wishbones on my undropped stock A axle. The axle has '46 1/2 ton spindles on it, and a new Mr. Roadster spring with a custom reversed eye main leaf. I've got custom made 1/4" angle iron brackets which make the bone mount about 3" under the frame. I haven't permanently mounted the brackets yet.

Here's the problem. If I pull the bone up to the bracket from it's resting position, my angle finder shows the axle sitting a 90 degrees, or 0 degrees of caster.

Now my question. If I run my adjusting heim joints all the way in, set my mounting brackets with the axle sitting at 0 degrees, will I be able to properly set my caster to the desired 5-7 degrees merely by backing out the adjusters - or will they only 'push' the axle forward without leaning the axle back to gain the proper caster?

I'm wondering if I'm going to have to pie cut my bones in order to lean the axle back, or if the adjustments will gain me the proper settings I'm supposed to have.

 

Pie cut or lower the rear mount.

 

Caster.

NOT Camber.

 

Also the angle your refering to is castor, not camber.

 

Okay, I get them mixed up. However, seems everyone knew what I was talking about.

 

You will have to cut a relief cut in the wishbones about 3" back from where they attach to the front axle, from the underside of the wishbone. Cut it about 3/4 of the way through, then bend it up at an angle of about 4 to 6 degrees. The cut will open up a bit at the bottom, (about 3/16"). After both wishbones are bent exactly the same amount, weld up the relief cuts. Now when the ends of the bones are pulled up to the brackets (3" below the frame), the axle and kingpins will be tilted back at the top by the correct amount.--Some people do it as I just outlined, some prefer to take a pie shaped peice out of the top of the bones. Either way will work.

 

On a stock Model A the wishbone is mounted to the bottom of the hogs head, bellhousing which is far below the frame rail.

Ron

 

Thanks Brianangus! That is unfortunately what I thought I would have to do, but didn't want to. I was hoping there was an easier method, but such is life.

 

Goztrider--while you're at it, check and see if the crossmember has a 4 to 6 degree angle in the area where the spring bolts to it. It should be tilted down at the rear, and the angle measured from the top of the framerail. If it doesn't have, you will throw a real ***** of a spring bind into the leaf spring when you tilt the axle by the recomended amount. I have seen some model A frames with the correct angle, but I have seen just as many with no built in angle at all. On the ones with no angle built in, an easy fix is to have the local machine shop make a tapered shim about 10" long with a 5 degree taper ---not end to end, but cross-ways. Just drill ahole on center for the spring-pack thru bolt head to fit into, and sandwich the shim beween the top of the spring and the underside of the crossmember. This will eliminate the spring bind, and avoid the problem of having to burn out and rework the crossmember.---Brian

 

if you pie cut,what do you about the welds,do you blend them in with a grinder,would look the best but what about strength?reason i ask is i have some bones someone ground down and blended those front welds and didnt know if i should weld them back up

 

What would be the best way to figure out if it has the angle built in? I have the spring pack tightened down into the cross member now - could I just lay the angle finder across the bottom of the pack and see if it shows the 4-6 degrees of built in caster?

Also, I don't know if it makes any difference, but this is a Ford Model AA truck frame.

 

I just went back out and put the angle finder on 2 different places. I set it right next to the upper 'guide' where the banger hand crank p***ed through (and also holds the U-bolts in place) and again at the bottom flat against one of the leaf springs next to the U-bolt bottom plate.

The upper location showed 94 degrees, which should be a 4 degree lay back in the cross member. The spring showed the same thing - 4 degrees off center laying back.

Is this correct?

I've also just made two 1/8" cuts in each bone from the topside going down, closed the cuts, and welded the **** out of them. Weld, grind the welds, weld a bit more, grind some more, weld a bit more, then grind until I figured it was right. This should give me plenty of caster, shouldn't it?

 

at this point strength isn't the question. the front axle pushs the bones back! the welds if done with a mig should be 60thousand psi. just be clean and dress them back. Brainangus did a good job explaining that program!

 

When you piecut, youwill find that the bones are quite thick material, about 5/32" thick. Use a grinder to but an almost full depth 45 degree bevel around the mating faces, then fill the resulting 90 degree gap completely full of weld, and let the weld actually 'hump up" beyond the outside of the bones. Then you can grind it back flush with the outside. If you prepared the Vee's correctly, there will be enough weld left in the Vee to hold things securely.

 

You should be okay with that. I did a little quick math, and found that a 2 1/2" deep cut, openend up 3/16" (+saw cut width)will give a about 4 degrees.

 

One cut from the bottom to the top (chopsaw blade width) will lower the rear of the bone about an inch, depending on the length. Just did a set yesterday.

 

Unfortunately, I didn't do this. I welded with only a small wire-feed welder, but I know I definitely got good penetration where I was welding.

One thing I've learned with this little welder is to go SLOOOOOW and allow my puddle to 'go deep' into the metal where I am welding so as to get as much penetration as I possibly can. As a result, I still wind up with the large 'hump' that winds up being ground down flush.

Everything seems to be okay. I just hope everything holds together.

Thanks for the advice guys!

 

Goztrider---I'm sorry guy, but that just won't do. No 110 volt mig is going to get enough penetration to do what you want to do. By the time you grind off all the humped up weld, you will end up with about 1/32" of actual weld metal, and about 1/64" of penetration. It will look excellent, and the first good pothole you hit it will break and drop your front end onto the road. I can not say this loud enough, nor enough times. 110 VOLT MIGS ARE NOT FOR THIS TYPE OF WELDING ON CRITICAL SUSPENSION COMPONENTS.---Brian

 

No problem then. I'll run the setup over to a buddy's place and see if he can dip down into where I've welded and run a good deep tig bead over it and then go from there.