The Master Cylinder Porsche 928 Tips
1987 928 Needs Shocks or Alignment?
Q – Hi MC I am one of the forgotten club members. I have a 1987 928 S4 (a.k.a. Shark) with about 85,000 miles on it. The car is all over the road and it follows the ruts like they were railroad tracks. I was hoping that I just need an alignment but a friend says that the shocks are shot. This is my first Porsche and I was warned that the purchase price is just the cost of admission, so I am ready to fix it. But where should I start?
A – Since this car is new to you, an inspection will reveal issues that may affect the alignment or ride of the car and you should start there. If you can get under the car with the technician, he can show you the obvious problems and then prioritize them for you. Finally, aligning a 928 is a lot different than aligning most cars. Porsche provides many adjustments to perfect the handling of the car and aligning these cars is a science. But, back to the basics, start with the tires. Are they actually round? Are the wheels straight? What is the correct inflation? It may sound elementary but what most people think is “an alignment” is usually something else. If you have never driven a car before with really wide tires, even when the tires are perfect, the car will tend to “track” depending on the road surface. This alone can be very disconcerting if you don’t expect it. Of course, if you find a problem with the tires, you probably DO need an alignment, as well as all the other parts that keep the suspension in alignment.
The car is “suspended” by control arms, ball joints, bushings, springs, and shocks. Steering consists of the tie rods, tie rod ends, steering rack, steering shaft and more of those rubber bushings. At 85K miles and 20 years of age, any of these parts might need to be replaced for the chassis to respond to alignment. For instance, your chiropractor will not be able to adjust your broken leg.
An alignment is done “statically” (with the car standing still), on a pedestal called an “alignment rack”. As you drive your 928, the force of the road, the weight of the car, and the power transmitted by the engine and brakes conspire to “change the alignment” dynamically. Since your car was designed to cruise at 130 MPH, the suspension is biased towards stiffness and stability. The oddest part of a 928 alignment is that even lifting the car during the process changes the ride height and attitude of the chassis. The trick is getting the alignment adjusted while the car is resting on its weight without raising it.
Once the worn parts are replaced, the new shocks installed and tires verified, your 928 will track just like the Road and Track test when you lusted after it in the 80’s. MC
My hatch release is driving me crazy
Q – My 928 hatch release is driving me crazy. Sometimes it works and sometimes not. The other thing that’s strange about the car is the window switches. They worked fine until I parked the car for a few weeks and now one works 9 times out of 10 and the other one only works if I push it down really hard. I already replaced them but I got them online, not from Porsche. Tom
A – The problems that I see most frequently on 928 electrical issues have to do with storing the car and this goes for 944, and Carrera too. The switches get oxidized and quit working. If you keep trying the switches sometimes they will miraculously start working again and the more you use them the better they will work.
I usually trust original Porsche switches but my faith was recently shaken when a brand new switch blew the fuse for the windows as soon as I plugged it in. The markings on the switches were identical for the O.E. switch and the aftermarket switch. Both were made in Hungary, by the same manufacturer, had the same markings, with only one exception. The Porsche switch was date coded. And for the extra 30%, it still blew the fuse.
As far as the hatch release, once you go through all the usually tests and adjustments, you will notice that the switch only works with the door open. I was fooled by this one and wasted some time and money (mine) researching a phantom problem. Sometimes I am better at giving advice than taking it. I should have read the book on this one. Duh! – MC