A-Arm Rebuild
Filed Under Fox Mustang
Due to the amount of cost and work it takes to do an a-arm rebuild, swapping bushings and ball joints, you can’t beat the price of a set of new Ford Racing arms with the low friction ball joints and stiffer bushings (part # M-3075-A). However, if you’re a glutton for punishment (as I seem to be), and you’re dead set on the improved geometry afforded by a set of offset bushings, prepare your self. Now, it probably would have gone a lot quicker and smoother had I worked on a cooler day, but I couldn’t change the weather and I was anxious to get the car to the next autocross.
Parts:
- Moog ball joints (2)
- Steeda offset a-arm bushings
- ball joint press
- wrenches
- primer & paint
The first thing was to disassemble the suspension. I have the shorter H&R Race springs in my car, which made removing (and installing) my springs possible without the use of a spring compressor. The control arm bolts are often so tight they need a breaker bar to remove. But getting access to the bolts isn’t all that difficult.
Once you have the arms removed, time to get them torn down. Start by removing the ball joints with a ball joint press. While not hard, the ball joint is press fit and takes a little bit of time to remove.
Removing the bushings isn’t very hard, just smelly and messy. A few minutes with a torch and they were burnt out. To get the shells out, carefully cut a notch through the shell, but not through the a-arm. I used a sawzall with almost zero pressure, and checked the cut’s progress every few seconds. Cutting through the shell releases the tension on the arm and allows the shell to easily slide out.
Use the opportunity to clean up the arm and apply some fresh primer and paint.
The new ball joints go in about as easily as they came out. It isn’t rocket science, it just takes some effort and time to crank down on the press. Just be sure the new ball joints go in squarely.
Some people reuse the stock shells and just slide in the new bushings, but the offset bushings used here required 0.100 to 0.120 inch of spacing on the shells from the control arm (2 dimes stacked together are about 0.105″ thick. 2 pennies are 0.115″ thick). The new bushings come assembled in their shells, so separate them to work with just the bare shells. To press in the shells I was able to configure the ball joint press in a way to get the job done. Some people have an issue keeping the “ears” of the arm from collapsing. The easiest solution I’ve seen was where someone used a socket that was just the right length as a spacer.
After the shells are in, pressing in the busings is pretty easy. Grease up the bushings with the supplied grease, and in they go. The sleeves go back in last.
A little admiring of a finished arm. And this temperature reading was taken in the shade - it was hotter in the sun on the driveway where all the work was done.
Then everything goes back together the opposite of how it came apart. The only difference is I waited to torque down the control arms with the car on some ramps when the suspension was loaded. It’s a little harder to get at them this way, but I wanted to be sure the arms were at ride height so as not to get any “preload” torqued in them at an incorrect angle.
I hadn’t spent a whole lot of time with the car before doing the rebuild, so the “before and after” is difficult. What was instantly noticeable was the lack of popping from the worn ball joint. I also noticed extra tightness in the feel of the steering, which was probably due to both the fresh ball joints and bushings, and a little extra feedback due to the extra caster. Again, all this touchy “feely” stuff is very subjective. I wish I’d had more time behind the wheel autocrossing to give a better before and after, but such is life.
Would I do it again? Yes. But a few weeks after I did my car, a friend and I swapped a set of the Ford a-arms in his car. With the exception of one of the stock springs being really difficult to reassemble, it was a much easier job, and on the street you really can’t tell the difference in the slight alterations to the geometry caused by the offset bushings. I’d only recommend going this route over buying the new a-arms if the slight offset in geometry is that important to you. In my case, it was.