How to: Upper and Lower Control Arm replacement. Let me start by saying this a time consuming, mildly complex, frustrating, and potentially dangerous task. It is my advice that if you are lacking in mechanical expertise, or do not have access to air tools that you let a professional do this one. I managed to do both sides of my truck in about 12 hours, including the installation of a new sway bar. What you will need. -Jack, two jack stands. -Basic tools (wrenches, sockets, extensions, regular car tools..) -Strut spring compressor (don’t skimp, your safety depends on this tool working well, and being strong) -Air tools (DO NOT ATTEMPT TO REMOVE LOWER CONTROL ARM WITH OUT AIR TOOLS) - 30mm deep socket, impact gun rated. -off set box wrenches, metric. -1/2 in breaker bar -Pitman arm puller -Pickle fork and hammer - a LOT of penetrating grease, for many of you this will be the first time your suspension parts have been worked on since your rig left Kentucky..expect them to put up a fight. - a good buddy to hand you tools, engage in witty banter, and to operate a jack for you. Now lets get started!! I recommend you start this process by having the underside of your vehicle cleaned, a lot of automatic car washes have this feature, if not a do it yourself spray should allow you to do it yourself.. I went to a DIY wash and was able to spray my entire work area by simply turning the wheels to allow access. A lot of road grime builds up on the underside of your rig over the years, and a cleaner work area will not only make this process easier, but also more enjoyable.. nothing like having dirt fall onto your head while your wrenching away, you know? I also recommend you apply a very, very, very heavy coat of penetrating oil to every bolt you intend to remove, pay extra attention to the lower control arms, as they will have the most corrosion, and grime on them. Now then go ahead and get your work area prepped, and get the truck jacked up and on jack stands. Remove the negative lead to the battery as a good knock in the right place where your going to be working could very well cause airbag deployment if your unlucky enough. Remove the wheels on both sides of the vehicle. Your next step is going to be loosening and removing the front sway bar, go ahead and start by loosening and removing the end links on both sides of the vehicle (even if your only replacing one side of the suspension), and don’t worry with the vehicle in the air the sway bar is not under any degree of tension worth noting. After you have removed the end links, go ahead and remove the brackets holding the sway bar to the frame, remove the sway bar if possible (I was unable to manipulate it out of the vehicle, my front differential made it impossible, I was able to work around it with it moved towards the rear of the vehicle and hanging on the LCA’s. Now is a great time to inspect your end links, end link bushings, and your sway bar bushings for wear and tear. With the sway bar out of the way it is time to remove the strut assembly. Go ahead and get your strut compressor mounted onto your springs, the more “links” you are able to compress, the easier it will be to remove and install the assembly, I was able to make it work with 4 links, but would have had a much easier time reinstalling the spring if I had been able to get more links. Do not begin tightening your strut compressor jest yet. From the engine bay, loosen the three outer bolts on top of the strut tower brace, on the driver side they are clearly visible, but on the passenger side they are hidden under some pipes, I was able to get the socket (13mm deep) on from the wheel well, and then manipulate an extension through the pipes (safely) to the socket, I used an air wrench to effortlessly turn the bolts off. DO NOT LOOSEN OR REMOVE THE LARGE CENTER BOLT. Use a floor jack to articulate the suspension upwards, the further the better, but be mindful not to lift the vehicle off of your jack stands, as this creates an unsafe work condition. After you have lifted the suspension, start tightening your strut compressor down, ideally when your done there will be no space left between the links of your spring. I was able to turn mine with hand tools, but if I had been able to manipulate an air wrench in there, it would have been far less time consuming and more enjoyable. After you have compressed the spring, lower the jack, you should be able to see somewhere in the strut assembly that tension has been removed from the device, I was able to see where the bottom of the spring left the strut assembly, if you do not see this, or are unsure you have compressed the spring enough to safely remove it from the vehicle, do not proceed, go back and try again. However, if you are satisfied with your handy work (as we all should be ) go ahead and remove the lower mounting bolt. lower mounting bolt, and bad tie rod end Now then go ahead and manipulate the strut assembly out of the vehicle, I had the best luck rotating the strut 90 degrees to the right, and pulling the strut towards myself, and towards the front of the vehicle. I found it helpful to articulate the suspension upwards again to provide more clearance from the UCA. Once the strut is removed, you may wish to have your struts/springs replaced, I will cover this procedure next week when I install my new KYB struts and Ground Force lowering springs, otherwise set the compressed strut assembly in a safe place, where it will be undisturbed. It wouldn’t hurt to “point” the spring in a safe direction either. With the strut and sway bar removed you are now clear to work on either the upper, or lower control arm. I was replacing both, as well as the tie rod ends. I started from the top and worked down, doing the tie rod ends last. To remove the upper control arm lets start by first separating the ball joint from the steering knuckle, loosen the retaining bolt, but leave it on the bolt with a full “nut” worth of threads, this will prevent the knuckle from falling when you separate it from the ball joint. I recommend you support the knuckle with a length of rope. I went around the strut tower, and wrapped the line around the wheel studs with great effect. Use a pitman arm puller to break loose the ball joint from the knuckle. Once it has broken free, remove the retaining nut and separate the two components. The upper control arm is held onto the frame of the vehicle by two nuts located on opposite sides of the strut tower, I recommend you use a breaker bar to get them loosened up, I used an air wrench to turn them off the bolts. On my truck the ABS sensor wire was routed through the UCA, if yours isn’t, go ahead and remove the arm by rotating it downwards and towards yourself, if it is it can be unplugged in the engine bay, follow the wire up to locate the plug. Installation of the new arm is the reverse of this procedure, be mindful of any camber plates that were under the old UCA nuts, reinstall them if they were present. For legal purposes I will not post torque specs, but you can find them for your year explorer in a Chilton’s Manual. Be sure to torque all bolts to specification. And I recommend you install the new UCA before attempting to work on the lower. With the upper control arm in place we are ready to remove the Lower control arm. Start by removing the break caliper and the break rotor, this will allow access to the lower ball joint, as well as the tie rod end if you wish to replace it at this time..same goes for your break rotors and pads. Hang the caliper by a length of rope. Honestly, its not worth potentially replacing break lines/caliper and bleeding the lines because you were to lazy to tie a knot in some rope or an old wire clothes hanger folks. Now lets go ahead and separate the lower ball joint from the steering knuckle, Remove the cotter pin, and loosen the crown nut. Now its worth noting that my Chilton’s manual said I could use a “c clam style puller” to separate the two components, but I was unable to locate such a puller in town. I was able to successfully separate the two with a pickle fork and a large hammer, do not use a pickle fork if you are not going to replace the ball joint, as it will completely destroy the ball joint’s boot. After you have separated the ball joint and the LCA, remove the crown nut. There are three bolts that hold the LCA to the frame of your truck, a very large one located towards the front that travels through a bushing, we want to turn the nut on this bolt(30mm), located towards the rear of the vehicle. This bolt was factory torqued to 295 ft/lbs.. and as such I feel it is my responsibility to express the futility of trying to do this by hand. This particular bolt despite the extremely heavy coats of penetrating oil, gave my $150 impact gun a run for its money. Loosen this bolt first. I recommend you support the LCA with your floor jack before attempting to loosen the two remaining bolts, and before pushing/pulling the front bolt through the frame and out of the LCA. With these three bolts and the ball joint separated, the LCA can now be safely removed by rotating towards the centerline of the vehicle, installation is the reverse of this procedure. Be sure to torque all bolts to specifications. I was unable to procure a wrench to torque my front bolt back into the high spec, so I torqued it to the 200 ft/lbs my wrench would go to, and I had a mechanic torque it the rest of the way when I had my alignment done. Also be sure to align the “flag” on this bolt with the hold in the frame, or you will be correcting it later on. If you have a 4wd explorer, now is the most opportune time to replace/upgrade your front sway bar, as removing the sway bar with out removing the LCA appears to be all but impossible. So if your still with me you have the majority of the work done and it time to get your strut assembly back in place. Getting the strut back into place can take some doing, try and manipulate it as best you can, some force may be required, but be mindful of the amount of force you are holding contained in your hands while you do it. Once you have it back in place secure it to the strut tower with the 3 bolts from earlier. You may need to pull the LCA downwards to align the hole through the strut with the hole through the LCA. Once you have the lower bolt in place and firmly tightened. Go ahead and jack the suspension back up to compress the strut assembly, this will make removing your strut compressor much easier. Remove your strut compressor, reinstall your break rotor and caliper. If your replacing the other side as well, it should be like déjà vu. Otherwise if your only doing the one side, go ahead and re install your sway bar, make sure its centered before you tighten it up to the frame. Thanks for taking the time to read my lengthy write up, and stay tuned for struts, and rear sway bar installation write ups. Also I’m certain I have left something out and many of you will have questions, so feel free to ask away.