While never known as the tightest ships in the fleet, Fox-chassisMustangs are at that age where creaks and groans accompany nearly anymotion. Good as you are to your 5.0, no doubt you've noticed itwandering on the freeway, wallowing through culverts, and generallyfeeling loose. It's time to lavish some love on the chassis.
From the most fastidiously maintained personal favorite to run-hardbeaters, old 5.0s fall prey to time and mileage. With 100,000 milesbeing low mileage for today's Fox Mustangs, is it any wonder the typicalchassis wear points are highly suspect? Tires, struts, and shocks areall no-brainer maintenance items in this age group. But for many owners,changing bushings in the control arms, steering rack, sway bars, andother areas is a first-time concern, as is the condition of the ragjoint in the steering, the inner and outer tie rods, the pinion snubber,and the spring isolators. In short, if it's rubber or plastic and it'sbeen working for a decade or more under your Mustang, it should at leastbe looked at.
To get a better idea, slide onto your imaginary creeper with us and takea quick tour from grille to taillights under a 5.0. Item one is thefront sway bar. A simple steel bar, nothing bothers this thing short ofhitting a tree, but the bushings it pivots in soften, crack, and loosenup, and the end-links almost always bend. The bending comes from thesharp angle the end links are contoured to during maximum sway bardeflection. Curiously, the light blue end-link bushings are probably themost durable bushings in a 5.0. While likely slightly deformed, they areprobably OK.
Next back is the steering rack. Its only common wear items are the innertie-rod ends. These are a typical cause of freeway wander and "loose"steering. The rubber boots on the rack are occasionally rotten orpunctured as well.
Horse Sense: Should you be opting for moreaggressive lowering than we are in this story, you might considerupgrading to adjustable tie-rod ends, commonly known as bumpsteer kits.Bumpsteer is a symptom of toe changes from the suspension moving up anddown, which can actually cause the car to change direction. MaximumMotorsports offers two variations of the adjustable tie rods, one with atapered stud for stock K-members and one with a bolt-through spindle forits tubular unit. Obviously the latter offers a greater range ofadjustment than the former. It also costs a bit more at $149, versus$139 for the tapered-stud version.
On the outer end of the rack are the outer tie-rod ends. These do wear,but not as rapidly as the inner variety. Also, they are easier and lessexpensive to replace, so they may have already been changed.
Between the steering rack and the upper steering column is aninterme-diate steering shaft, commonly called the rag joint or steeringisolator. It is a common wear point and source of wandering steering on5.0s. Cracking and deformation are the typical failure modes. Anyvisible play while a buddy works the steering wheel back and forth insmall, sharp motions is also cause for replacement.
On the front lower control arms, consider the control arm itself--they docrack. In addition, the ball joint at the spindle end will wear and thelarge inner bushings where the arm attaches to the K-member crack andmush with age. A steady diet of extremely hard driving will even squishthe control arm bushings out of the A-arms, a condition the mechanics atthe Bondurant driving school reported took about one month to occur onthe school cars. Those cars are driven like rented mules all day, everyday, and we mention the phenomena in case you're working on an old racecar or your 5.0 has taken a couple of kids through high school.
The front struts are obvious wear items, so we won't detail them here.Their companions, the springs, are durable and essentially never go bad,but not so the rubber isolators at both top and bottom of the springs.Look for deformation and cracking.
The weakest point of the Fox chassis is the midsection, in a linerunning athwart the car just forward of the rear of the door opening.Look for cracks in the floorpan, especially around the holes where theseats bolt to the floorpan. The solution, as well as the preventativemedicine, is a beefy set of weld-in subframe connectors.
Sitting 1 inch lower than stock, our rejuvenated suspension gives thelooks and handling improvements craved by street drivers. |
(above & below) Besides the clues given by tire wear and through thesteering wheel--wandering or imprecision--you can spot worn steering andsuspension parts with a few easy checks. Feeling for play at 12 and 6o'clock in the tire will uncover loose wheel bearings (an adjustmentissue) and worn ball joints. Any play in the tire from the 9 and 3o'clock position signals worn tie-rod ends. You can spot the bad areavisually while a helper wiggles the tire. Look for where the motionstops in the steering or suspension and that's your troublemaker.Likewise, wiggling the steering wheel and observing the rag joint andtie rods will give a quick indication of their condition. |
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Admittedly there isn't too much to see when eyeballing control-armbushings such as this rear upper arm at the differential. However, agood, up-close examination with a flashlight should uncover deeplycracked or partially squished-out bushings. Be careful, most of thevisible bushing area is usually a metal backing. The rubber part isnormally visible only at the outer ends. This one looks OK. |
Urethane bushings are readily available and provide a great increase incontrol-arm precision, but they require careful (and sometimesphysically difficult) installation bordering on suspension blueprinting.If you're setting up a dedicated open-track machine, then such bushingsare worth the effort. But daily drivers don't benefit from this extrawork because they aren't driven hard enough to greatly deflect the stockbushings. These are front lower control-arm bushings from MaximumMotorsports at $59.95. |
The rear upper control-arm bushings seem dedicated to remaining in thedifferential's iron ears. This $39.95 bushing press from MaximumMotorsports makes persuading the bushings in and out much easier. |