Wow, my parts count is finally going down!

Yay!  I started reassembly today!

But before I go into those details, I promised awhile back to post about the fabrication on the lower control arms, so here goes.

Like the upper arms, I am using the roller kit from Opentracker Racing with the removable lower ball joint, spherical bearing in the pivot, and reinforcement that boxes the arm, making it very strong and stiff.  I probably don't really need the reinforcement, but I thought it would be a fun project.

The first step is cleaning up the original arm, popping out the stock rubber bushing, and drilling out the riveted-in stock lower ball joint.  Taking out the bushing was easy.  They were so worn on both sides that they just fell out.  So the first real work was taking out the lower ball joint.

The first step was drilling a 1/8th hole through the rivet, then slowly enlarging it.  I had originally intended to keep drilling until the rivet was essentially gone, but I read in my favorite Mustang forum that once drilled you can use a die grinder to cut a slot in the rivet head, then use a cold chisel to easily pop the head off.  Then an easy matter to pound the remainder of the rivet out.  So that's what I did.

Here's a pic of the arm with the original 1/8th inch hole drilled through all three rivets.

Next pic shows the holes just a bit larger.

 I don't have pics of cutting the slots across the rivet heads or pounding the rivets out, but it went real easy at that point.  Once the rivets are out the ball joint basically falls out.  What's left is a dome that the ball joint rode in.  This dome is one piece of hardened steel that is spot welded onto the bottom of the arm.  Here's a pic of the dome from the top.  At this time I did not take a pic from the bottom.

 The objective with the removable ball joint is to weld a sleeve that has internal threads to the hole where the original ball joint was, then simply screw in the new ball joint.  I thought "No problem", jigged up the arm in my drill press with a 2 inch bi-metal hole saw, set the RPM to 350, squirted on a bit of cutting oil, and promptly flattened the teeth on my hole saw.  Damn, that hardened steel is tough!  One ruined hole saw now in the scrap pile.

So then I thought "ok, I'll use a small drill to drill a series of holes around the perimeter, then cut out along the holes."  One dull and dead drill bit later, with nary a scratch on the steel, I abandoned that plan too.

I considered drilling out the spot welds that hold this hardened steel on the lower arm, but was uncomfortable doing so since the arm itself is not all that thick, and I suspected that I would want the structure that the hardened steel provides.  My quest now turned into finding something I could cut this crap with.  That something ended up being a die grinder.  I bought a 2 inch air driven grinder from Northern Tool along with a bag of a dozen cut off wheels.  With these wheels I was able to cut off the dome, and cut a series of radial slots in the remaining steel, as you can see in this pic.

I then used a small 1 inch cutting wheel and a 1 inch grinder wheel in my Dremel to cut out the rest.  Once I figured out how to do this, and got into the rhythm of it, I was able to cut out the hole in about an hour.  Once rough cut, I used a grinding stone to round out the hole to the size needed to insert the sleeve for the new removable ball joint.  Here's a pic of the arm from below with the hole at proper size.  You can see the hardened steel plate spot welded to the underside.

 Same arm from above.

 Here's a pic with the sleeve pressed into place for a test fit.  You can see the internal threads for the new ball joint.

And here's a pic of the sleeve for the spherical joint that replaces the stock rubber bushing, pressed into place for trial fit.

After the test fitting, it was into the sand blast cabinet for clean up before welding.  Here's a pic of the modified arm next to the other lower control arm still in it's original state as it came off the car.  It shows the amount of work that went into the fabrication to this point!

I took my time in welding in the two sleeves.  John at Opentracker cautioned me to weld about a quarter of the perimeter at a time, letting it cool completely in between welding, to prevent the sleeve from shrinking.  I took his word for it and took some time to do the welding.  For the ball joint sleeve I had my Hobart Handler 140 on 3 of 5, with wire speed of about 30.  For the spherical joint sleeve, I turned it down to 2 of 5 and wire speed of about 25, since the arm is a bit thinner there.  I welded both sides of the sleeves.  Here's a pic of the underside of the ball joint sleeve after welding.

After the sleeves are welded, and I tested the fit of the ball joint and spherical bearing, I started on the reinforcement of the arm.  The reinforcement consists of a simple plate that is welded to between the side walls on the underside of the arm and to the sleeve for the lower ball joint.  This ties everything together and makes for a very strong and stiff assembly.  This plate has holes in it already for the lower ball joint and access to the sway bar link, but I had to cut the holes to get access to the bolts for the strut rod.  The plate does not come with these holes since the stock strut rods attach to the arm through pressed in studs, but I am using adjustable strut rods from Global West which use larger bolts instead of the studs.

I clamped the reinforcement plate in place, then ran a pencil around the wholes for the strut rod bolts to mark where I needed to drill.  Here's the plate with the marks.

Back to the drill press, this time with a a 1 1/8th inch whole saw, which allowed clearance for the nuts, and I have a reinforcement plate just about ready to install.  Right?

Wrong!  The holes I just cut are big enough for the nuts, but not big enough to get a socket over the nuts to tighten them.  Almost a big mistake there!  Here's a pic of the plate, clamped in place, with the bolts and nuts for the strut rods.  The marks on the plate are where I need to enlarge the holes to get a socket onto the nuts.

Luckily this was fairly easy to do.  I used a medium sized stone in my Dremel and enlarged the holes until I could get a socket on the nuts with a bit of clearance.  By the way, you might wonder why the arm is already painted blue in the pic above.  I painted the lower side of the arm, and the inside of the reinforcement plate, before welding it all together since I new I would not be able to paint the inside once assembled.  Although the design does allow water to escape, I still wanted to have as much protection as possible.  I know that the welding process will burn off the paint around the joints, but at least most of the inside of the arm will have some protection.

Now that the reinforcement plate is done, it's time to weld.  I held the plate in place using C-clamps and vise grips, as shown below.  I set my welder on 2 of 5 and wire speed 25 again, since the reinforcement plate is thinner than the arm.

After welding, I sand blasted the whole assembly again using 80 grit glass beads, and painted the arm Ford blue.  I just wanted something other than the standard black.  Here's the completed and assembled arm.

 And the view from the bottom with the reinforcement plate welded in.

Overall a relatively easy and fun project to do.  The hardest part was figuring out how to cut the hardened steel, but even that went quick once I figured it out.  This arm took me three days of work, the other arm took me about five hours.  I highly encourage you to try this project, if I can figure it out than anyone can.

Contact me if you have any questions or comments.  I would love to hear from my readers!