Mark Anderson, http://www.928intl.com
You need to disconnect the upper ball joint from the spindle. There is
a special tool that puts pressure on the ball joint to force it out. Sort of
like a mini press. There is also a pickle fork that can be driven between the
ball joint and the arm. It works, but will probably destroy the rubber boot.
My preferred method is using two big hammers. One hammer goes against the spindle on one side and the other is used to hit the spindle on the other side. The joint has to be loaded for this to work which with the spring load of the shock is enough. The ball joint goes through a tapered hole. It is the taper, which gives it the strength. When you hit the spindle with a backing on the other side the spindle momentarily deforms causing the taper to lose its grip. The ball joint will literally pop out.
On the S4 and newer the ball joint is part of the upper A-Arm. It cannot be replaced. The A-Arms - ready for this - are $950 each. There is a guy on the forum who is prototyping a replacement to sell in the $250 range with the ball joint. Not cheap but a bit better than the stock arms.
To test the ball joint clean it out with solvent after removing the boot.
It the joint moves freely then it is bad. There should be some natural resistance when moving the ball in the arm. The joint should stay in one place and not be effected by gravity. Unless you clean the joint, the old grease will add resistance and make a bad joint look good. You can buy new boots if they are shot and the joint should be repacked with grease before putting the car back together.
One more note. Once the nuts are removed from the inside of the fender well, the arm will side out from the outside. It takes a bit of prying.
However, the geometry of the suspension will keep the A-Arm pushed into the body. Once you remove the lower arm and the bolts on the shock tower the whole thing should come down easily enough. Remove the three bolts on the shock tower not the one in the center. If you remove the center nut the whole thing will fly apart. It helps to have a second person helping on this one since the entire suspension is heavy.
One of the things I would investigate is why a low mileage car has bad A-Arm bushings. It might be time to check the rest of the rubber bushings to see it someone did some detailing with chemicals and a steam washer. These bushings under normal conditions should go 150K to 200+K miles with no trouble. In fact, on all the cars I have seen there never has been a bad Arm bushing. By the time a 928 gets to me, it generally has some pretty high mileage.
Dan the Pod Guy
The lower control arms are held on with two cast aluminum clamps. The clamps are bolted to the body. With an air wrench it is pretty quick just to remove them. There is a tow plate over the front clamp held to the body with two smaller bolts. The tow plate is probably bent or at minimum scratched up. The A-Arm will come down over the shock and release from the bottom of the shock, but getting it back together can be a pain. I find it is much easier to drop the entire suspension as one piece and then put it back up as one piece. It takes a second hand to go smoothly although I have done it alone a few times. Over all R&R should not be more than 2 hours per side. After you have done one it will go quick enough. When putting it back together use some blue Loctite on the main bolts and torque them the factor specs. This is your suspension!
The lower arm has a couple of bushings. These I have never seen fail, but given the early departure of your upper bushings I would take them apart and inspect them. This is accomplished in the R&R so no extra work is involved.
Another possibility of play can be the upper bushing on the shock. The shock tower is floated in rubber. If solvents were used on the car they could damage the shock tower bushing as well. You will have to disassemble the shock tower to get a good look at it, but you can just check it visually when the shock is out. There is a rubber bumper or damper in the shock itself. These go with age and should be checked. The damper can be seen in side the plastic cover with a small light, but is more easily examined when the shock tower is apart. Refer to the parts page for an overview of the shock tower components.
If you drop the lower arm the shock can remain in place and everything will
drop out of the way.
Some people have used poly bushing for the A-Arms. I have not tried them, but from what I hear they mess up the original forgiving nature of the 928 handling. The true unique and safe feature of the 928 is the forgiveness it exhibits when you over drive a curve. Some cars just freak out. 911s tend to see their rear ends lead out of the curve. The 928 allows very late braking and will self correct like no other car. You might benefit from stiffer less forgiving suspension mods if you are tracking the car, but for street driving it is very difficult to beat the original handling characteristics of the factory suspension. Want some input on what can go wrong on suspension mods contact Bill Ball on the Forum.
A chock is a triangular piece designed to wedge under a wheel to prevent the car from rolling. Those of us living in San Francisco understand the value of chocking wheels while parked in steep hills. :)
Once you have the new wheel bearings, seals and A-Arm bushings you should be able to put the car back together in less than half a day and be on the road. The play in the A-Arm bushings makes it impossible for any alignment shop to set the front alignment correctly. Once back together get the car aligned or do it yourself using the methods described on the forum. Before having an alignment done set the ride height and then drive the car a few days to get the springs settled in. You may have to make multiple passes on setting the ride height. When adjusting one side count the turns. I mark the ring and then write down a mark for each turn. Adjust both sides the same amount until the car is very close to being correct. Once set in you can tweak one adjust a turn at a time until the car is perfect.
If you find other rubber bushing compromised I would give the car a complete going over. Failed bushings are not the norm for such low mileage and may be pointing to other issues.
The bolts are Cadmium plated to prevent corrosion. Unfortunately, this was not a great idea as the Cadmium wears off easily. If the bolts on the suspension have been polish to show, they will rust at an accelerated rate.
I have found lacquer thinner on bronze wool is a quick clean up for dirty Cadmium plating, but generally follow this treatment up with either some clear sealer - Diamond Clear from Eastwood Products - or their fake Cadmium restorer kit. Either way you end up protecting the bolts from further corrosion and will save you some grief the next time you take things apart.
Good luck and get back on the road. You are missing the little bit of good weather the Maine Gods allow per year.
Dan the Pod Guy
Vertical movement in and out of the socket is what you are looking for.
If the play was without the nuts tight on the shaft that is not looseness.
Checked outer surfaces on the bushing is not necessarily damning. They are pretty thick and it is the part inside the housing that is doing the work not the outer edges that are exposed to ozone/UV and other offenders.
Jay may be making too much out of this. You can use a vice to see if there is any vertical play. But why? If the joint is stiff then it is good. If you want double confirmation then remove the boot, clean the grease out and see if it goes loose. With 47K miles it would be very rare to find a bad upper ball joint. Repacking the joint is fun. There is no zert fitting so you have to just force the grease in the best way you can. Putting the boot back on is even more fun.
Me I would leave the ball joints alone. Since you have the arms off and since you see some play on one side then go ahead and install new bushings.
They are cheap and will install in less time than you will spend obsessing over them being good or bad. That way you know they are good. If later you still find some play then you have eliminated the bushings as the problem and can move on to other areas. Part of doing your own wrenching is replacing parts that are in doubt simply because you have no labor costs.
You can justify these additional parts cost by the labor you save. Besides most mechanics will generally replace a lot of good parts simply because they have no basis to determine what is good and what is bad.
Most shops if they could sell you on the job would replace both a-arms, the lower ball joints, wheel bearings, inner and outer tie rod ends, rack boot and probably have the rotors turned and new pads installed. You would probably end up with new shocks as well. This way they would know that everything was right and not have to use any diagnostic ability. Successful shops become successful shops by turning a $50 wheel bearing job into a complete front end job and then having some sweet talking guy with a German accent tell you how lucky you are to have brought the car in just before it collapsed on the freeway taking out a tanker truck full of gasoline.
Any time you hear clunking then it is a good idea to be on the safe side - especially with suspension. Buy yourself a bottle of blue Loctite and use it on all of the nuts and bolts you reinstall. Also pick up a torque wrench and set the bolts to the factory specs. Many front end guys just use an air wrench set to max on suspension. This is a very bad idea. With the Porsche you can actually strip some of the treads. Never good when these are part of the frame of the car. Torque to wheels in two steps. If you put the wheels on with an air wrench or do not torque them correctly you will warp the rotors and end up with a pulsing in the brakes that can only be fixed with new rotors.
Dan the Pod Guy