rjtw

Hi there jhalsey,
I recently completely overhauled both front and rear suspensions with all new bushings, bearings, shocks, and tie rods; re-packed the U-joints, new rotors/pads/sensors, made the calipers and dust shields pretty again, installed new sway bar bushings, and did a lot of general cleanup. You can get a sense of what it's like starting at post 120 in my thread here: https://rennlist.com/forums/928-foru...l#post16207268
Also skip ahead to post 163-on where there's more on the halfshafts, brakes and more.

First and foremost: You will not regret this! Redoing the bushings/shocks makes the car drive like new again. And mine wasn't even bad by any means before I did the job, but the handling and crispness of response (with still a very smooth ride) is really fantastic. Go for it!

A few words of advice:
- Get a Harbor Freight 20-ton press, if you don't already have a press. You'll need it for the bushings, and then you'll discover that you need it for a bunch of other projects on the car, not least of which is the rear bearings. And yes, I recommend you change those if still original because it'll never be easier than when you have the suspension apart for the bushings. You may also need the press to get off the "collars" on the shocks.
- You can rent spring compressors for free/cheap at the local auto parts stores.
- On the front, if you're still original arms, you'll want rebuilt upper and lower A-arms (with new bonded-on rubber bushings) available from Mark at 928 International. There are some little bits and pieces you need for the front shocks as well.
- Now, a few specialty items you will absolutely need.
- A tube of Castrol Molub-Alloy Paste HT (Roger at 928sRUs). Formerly known as Optimoly and generally used for steel. More notes below.
- A tube of Castrol Molub-Alloy Paste TA. Same as above, but generally used for aluminum.
- A tube of "Sil-Glyde" silicone lubricating compound (Amazon etc.) for pressing in the stock rubber bushings. I wouldn't even consider going aftermarket here.
- And finally, line up all needed new nuts, bolts, cone washers etc. ahead of time. More notes below.
- Inspect and consider "doing" the U-joints while you're there (replacing the boots and re-packing grease; all available from Roger) and, in the front, it's more likely than not time to replace tie rods, boots and front bearings. (EDIT: I missed the cracked halfshaft boot above so you need to pull the halfshafts for sure - not sure if you'll find the joints are still OK or not)
- And finally, do not even attempt this project without downloading and carefully reading through the WSM and PET available for your car. There are some very helpful and important details there.

Regarding the Molub-Alloy Paste, this is the original stuff used by Porsche and it is a dream to work with. You'll want to study the WSM carefully and use the one flavor or other of this lubricant exactly as, and everywhere, specified.

Regarding new nuts/bolts/hardware, again please read the WSM carefully all the way through and follow its guidance on exactly which hardware to replace (it tells us) - that's at a minimum. Additionally replace any other hardware showing signs of corrosion. Evaluate the condition of your link pins once you get them out and replace if corroded. On the front, more of same, and I found in particular that many of the lower control arm bolts were quite corroded because they tend to trap water. I chose to replace all nuts/bolts/washers/pins regardless so lined up all the hardware bits ahead of time.

Be sure to have a torque wrench and use it to tighten everything to the values specified in the WSM (I think there are some handy dandy torque worksheets here on Rennlist too). Speaking of wrenches, there's a special wrench you can buy that is extremely useful for removing those pesky engine-side nuts on the upper a-arm, let me know if you need a link but if you do a search here you'll likely find it. Oh, and as you probably know but I'll repeat anyway here for completeness, you need to settle the front suspension before doing a final torque on the lower arms. I actually followed the same procedure on the upper arms, settle before final torque, out of an abundance of caution.

Good luck, take your time and it's actually a fun and rewarding project!

jhalsey

Rate, wow, thanks for your detailed response, especially info on the various lubricants. I’m still in the information and parts gathering stage so won’t be starting the actual on car work for a bit. I will post my progress as I go.

jhalsey

Rjtw, damn spell checkers cause more errors than they fix….

jhalsey

Tire pressures are 32 psi, monitoring system defeated. I will check in w you all when i get it disassembled on exactly what is replaced and what, if anything is not. I already replaced the cv axle on the other side some months ago.

Mrmerlin

tire pressure should be 36 front and 44 rear

this is also on the sticker inside the gas tank lid.

mj1pate

This has likely been mentioned already, but your alignment should be done on a “no-lift” type alignment apparatus.
Hawkeye machines are an example. An experienced tech will know to “help” a car’s suspension settle and run out, but these suspensions are notoriously stiff.
Locate a shop with a good reputation and a Hawkeye.

hacker-pschorr

Many threads on this subject (83 per the search engine). Few folks actually run that much, especially in the rear.

Here are a few of those threads for your reading pleasure:
https://rennlist.com/forums/928-foru...r-my-79-a.html
https://rennlist.com/forums/928-foru...-the-rear.html
https://rennlist.com/forums/928-foru...-pressure.html
https://rennlist.com/forums/928-foru...-pressure.html

hacker-pschorr

A proper alignment includes a full inspection of the suspension which cannot be performed with the suspension loaded.

Since these cars have adjustable ride height, checking that should too be part of the alignment.

Settling the suspension on these cars on an alignment rack isn't difficult, any competent alignment shop can do it. To be safe, bring along the pages from the WSM detailing the procedure: