86 F250 lowering jobbie... need engineering degree.

[Christ]

So the F250 that member 6Speed had is now mine, and I want to lower it... the rear is easy as pie, but ghe front uses Ford's twin I beam setup. DJM /used/ to make a bolt in set of beams good for 3", but they're now discontinued. Another option would be updated 87+ knuckles and the still produced DJM parts, but that's in excess of $800 worth of parts for a relatively mild drop and no additional benefits.

Can someone with knowledge on the subject please explain to me why Ford used ball joints in a solid beam type suspension arm? They can't articulate at all, because the mount points are locked in relationship to each other.

With the exception of easier steering effort, there is literally zero function that ball joints perform which is necessary to the I beam Ford uses here.

All that said, is there any reason that I can't replace the ball joints with custom bushes and hardened bolts, since they have no need to articulate? I realize that there will need to be a provision to allow the parts to slip for steering purposes, but otherwise?

[Cobb]

If its 2wd you could just go smaller wheels and tires.

[Big Dave]

Wow! Drop I-Beams are gone, too.

My truck is a rolling anachronism. Drop I-beams, 3.08 gears, and the reliable International 444E.

[slownugly]

what kind of bushings are you thinking about using? even though the ball joints dont move in the traditional manner of say a long arm/ short arm type suspension, they will still need to handle stress from all different angles.

a strong sealed bearing would be the only acceptable route in my opinion (such as wheel bearings or on upper strut mounting plates) but it would have to be very heavy duty. unlikely to find one small enough. Just a rubber bushing with a metal sleeve might be a bad idea. It will at least affect alignment not to mention what the stress will do to it.

i wouldnt touch the ball joints. ford uses some pretty beefy ball joints on the bigger trucks and they are a high failure rate item. imagine what that stress will do to rubber.

[Christ]

Bushing - steel sleeve with flange and grease grooves in it. I'm thinking about drilling out the knuckles of their taper and using a smooth hardened bolt in place of the ball joint stud, through a steel bushing. It'll more or less be like having two kingpins in each arm, a design they should never have left in '82.

[slownugly]

Oh ok gotcha. If you set it up the same as a kingpin then I don't see why it wouldn't work. The thickness of the bolt shank to the sleeve is going to be crucial.

Just to clarify the bushing will press into the arm and the through bolts will be where it turns? Is the main goal to adapt the 86 and older spindle onto the 87 arms?

[Christ]

No, I'm not swapping any other parts. 82-86 used ball joints in the arms, 87-02? used them in the spindles, both designs are functionally the same in that there is no spherical movement in the ball joints because the joints are locked together in orientation.

The bushes will resemble the large base of a ball joint, and will press into the arm [upside down] from it's normal orientation, so that the stud [bolt, in this case] sticks up instead of down. The bolt thickness will be the same as the widest part of the taper on a normal ball joint that goes to this truck.

The bushing will have a flange at the bottom and a pair of slip washers at the top and bottom both to hold grease into the bushing and to allow the bolt to turn inside the bushing without binding, allowing for steering.

The bolt itself will use a castle nut and cotter pin, same as the ball joint would normally.

SO basically, what I'm doing is replacing a spherical joint with a solid connection where no spherical movement is required, but inverted so that the stock front suspension remains intact while lowering the truck [because the spindle will be installed above the arm instead of below it.]

[slownugly]

Gotcha, have you seen any done like this yet?

[Christ]

Noap, I haven't actually, and before I bother with it, I'm gonna look through some ball joint dimensions [as soon as I find them] and see if I can find a matching BJ with the flange on the other side, since they're only $12 or so usually.

That would enable me to press in the joint from the 'wrong' side and achieve the same effect while using readily available parts.

The biggest issue preventing me from flipping the ball joint as they are is that the flange is on the wrong side. It's on the stub side from on the OE unit, flipping it over would mean that a hit to the wheel could loosen the ball joint from it's press-fit because there's no physical 'stop' to keep it from moving except a circlip.

I don't necessarily trust my life or the safety of others to a couple circlips.