DIY

Technical Information and Restoration Parts for the 928

Home Repair

So you want to repair your car yourself. There is a lot of advice on the Internet and particularly special information on the 928. This page is general and specific in nature. Lets start with some specifics.

The myth of natural talent. As a kid I took everything apart I could get my hands on. I rarely put things back together and when I did things rarely worked. There were always pieces broken or missing. This intuition led my parents to encourage engineering school. It was at engineering school where I realized I have no natural mechanical ability.

I write this to encourage those who have not tried to work on cars or your 928 to try. If you are reasonably smart you can learn most things. The 928, especially in the earlier cars, is well designed for repairs. Where many cars are not made to be repaired, but most German cars have a symmetry that once understood is easy to follow. So here are some tips that might help you over come your hesitancy and aid in getting good results.

Patience. Some people are patient and others are not. Patience is not necessarily a personality trait. The ability to carry forward with a project is to take breaks when you are stuck and look at the problem mentally. Before you can successfully take something apart it is important have a mental picture in your mind. Picturing the problem while you are disassembling something is the best way. If you are stuck stop. Do something else. Eventually you will see a clear way forward.

Keep a record. I am blessed with almost a photographic memory. It is probably a result of not being able to read until late in life, but taking a picture of your work either mentally or with a camera is important. As you take things apart take a picture at each stage. Beyond having a map of how to put things back together it will also provide a record of the parts that are worn or damaged. When unsure of what is wrong you have pictures to show experts or post to a forum. Numbering parts is also a good way of keeping track of the order of assembly.

Duplicate and special tools: Fortunately on the 928 there are not too many special tools required until you deep into the engine or transmission. Yet having the right tools are important. If you find yourself getting out a monkey wrench or saw to cut holes in the chassis for access you are doing it wrong and it is time to invest in the proper tools.

Given the low cost of tools today and the high cost of labor buying tools for the job is good economy. It is a good idea to buy duplicates of common tools like 10mm and 13mm wrenches. It is very frustrating to spend a lot of time looking for a tool - especially one used all the time. I have several 10 and 13mm sockets as well as an assortment of other common tools like screw drivers. When I misplace one I just get another. Eventually the misplaced tool will show up hopefully not inside something. Buy a good quality German or Snap On Phillips screw driver with a hardened tip. You will thank yourself for the extra investment when being able to remove stripped screws. If i have to rent something expensive like an engine hoist more than once I buy one.

Documentation is important. Having access to the manual and parts break down is critical. While Porsche manuals are obscure and brief at best, referring them before, during and after the job provides clarification. Each time you will gain more knowledge. The manuals can be found on line and there are many other resources of people who have done more difficult tasks.

Do not believe professionals. Shops are suffer from a conflict of interest. The structure of the repair business makes it almost impossible for shops to stay in business by doing proper repairs. If a shop touches a two dollar seal on your transmission then they own the entire transmission if it starts to leak from another seal. Thus the only profitable way for a shop to stay in business is to do the biggest jobs possible. Since all old cars need multiple repairs and since a shop can only make money doing complete repairs to the level of a new car, the costs of repairs are much higher than you can do yourself. Besides saving labor you can save money by repairing parts a shop would normally replace. Many shops lack expertise in the repair of 928s because they are relatively rare and characteristic design is quite different from other Porsches.

Used parts can sometimes provide false economy. If a part generally breaks after so many miles then the used part will generally break at about the same mileage. This is not true if on replacing the part you determine the real cause of failure. The same is true for new parts. Often Porsche used inferior products in particular hoses and upholstery. When replacing these parts it is wise to use alternative sources whenever possible.

The 98% rule. One of the finest finish cabinet makers I know is satisfied with doing a job that is only 98% perfect. Of course his 98% is generally better than most people's finished work. He claims every time he tried to go for that last 2% he screws things up. This advice comes from a qualified professional with 20 years experience. Each person has to define a place where the job is good enough. With Porsches people often obsess over the most minor details (Well this is not generally true of 928 owners). There has to be a stopping point. That stopping point is generally well before perfection is obtained. I find I can do a job and then wait. The next time I am through the area I see things that can be improved. Time and perspective puts things on your side. Also improving one area can highlight the deficiencies of another area. Sometimes you can look too closely at something and fail to see the overall picture. The human conflict between perception and reality is a age old subject best left to philosophers. A good read on the subject is "Zen and the Art of Motorcycle Maintenance". The book is more about repairing VWs than motorcycles but the author makes some very good points about the physical world.

Safety is critical. What is the point of attempting to repair your car if you hurt yourself and end up with serious injuries. Making sure the car is stable before crawling under it is a given, but so are eye protection, gloves and masks. Things like Brake Clean can be deadly and cause serious health problems. Paper masks are good for dust but then working with chemicals it is critical to use a respirator. You may look foolish and over cautious to others but your lungs will thank you later in life!

Double checking your work. One of the biggest mistakes new mechanics - and often experienced mechanics make - is to not tighten all the bolts. When assembling something using a paint marker mark each bolt as your torque them. This way if interrupted or even becoming confused you have a visual record of the bolts being properly tightened. Use of Blue Loctite on all critical brake, suspension and engine parts. Torque wrenches and specifications should be followed in almost all areas.

Trial assembly. There is nothing unprofessional about trial assembly. Testing how things go together or testing for leaks is entirely acceptable and provides a deeper understanding of the function of the assembly. For small parts disassembling inside a plastic bag is a good way to not lose small clips and such. A magnetic tray is a good way to keep small nuts and bolts in one place. Bagging and labeling parts in plastic bags is also a good way to segregate which things go with which assembly when you are waiting for cleaning or parts.

Think ahead to the next time. With the 928 often assemblies have to be removed to get to the repair. Many times several subsystems will have to be removed to facilitate a repair. For example almost anything done under the car requires the exhaust system to be removed. Changing the clutch master cylinder requires the brake master and booster to be removed. These are opportunities to freshen and inspect these components and even set things up for the next time they need to be removed. Changing the bolts and nuts on the exhaust system to stainless steel makes in easier to remove the next time. So does cleaning things before assembly.

Summary. These are only a few suggestions but the main thing to keep in mind is the 928 is accessible and easy to work on when the repairs are well understood and planned. Some repairs are cheaper to have shops do - like oil changes. Being very clear about what is wrong, defining the scope of repairs and providing the parts to a shop can and will save you a lot of money. Often it is best to pay a shop for an diagnostic and estimate of what your car needs. This way you can formulate a plan and prioritize what is repaired and what becomes deferred maintenance. Oil changes are probably the most over sold repair. I have never seen a car fail for lack of a periodic oil change. With the new synthetic oils a car can go on almost infinitely without serious engine wear. Scheduled services also contain a lot of fat and tasks you can perform yourself. Instead of a major service that can run into the thousands pay for a timing belt change and maybe valve timing and do the rest of the things yourself. Being informed about what really needs to be done is the most cost effective way of owning a 928.