Steering upgrade !!
My 928GTS was suffering from some sloppy steering. Not too bad I thought, not really something that would be high on my agenda. But all that changed when Peter, the owner of a local independent Porsche workshop, let me drive a 928 with his upgraded A-arm and steering rack solution. At first it was a bit different. You get used to some sloppy steering behavior I suppose, but it felt tight, less steering intervention required, less tram-lining, very responsive.
I decided to ask his offer for a fix on my car. We agreed and he had my car in his workshop for a day. The fix is basically two improvements:
- new steering rack bushings, aluminum style, special design. He designed these himself and has a machine shop make these for him. They are a tight fit to the rack and the cross member.
- new A-arm bushings, made from material called POM. This is rather hard and stiff wear-proof material also called Delrin. Also his own design. The bushings have an internal metal sleeve and special shims to make the A-arm fit perfectly. Yes, the Arms are not exactly the same as we found out. Left to right differ about 0.7mm in shim thickness in my car. Apparently the Aluminum cast is different.
The work is quite a bit. Both shocks need to come out, two nasty nuts must come out to undo the A-arm from the chassis, the steering rack goes on the workbench, and you definitely need a press to properly take out the old bushings and press in the new ones. After the process the car needs an alignment. He works with a local alignment shop and does the alignment himself.... as this is something only a 928 specialist can do right.
And then.... then there is a test drive. I just LOVE it. The steering is sooooo much better. So tight, so responsive. Especially braking on a bumpy road, or changing lanes on a motorway when there are tracks in the tarmac. Or if a road that is uneven. It makes steering a breeze. No more repetitive left-right corrections. The car is so stable at high speeds, unbelievable difference. This works awesome. And ....btw... it looks great too.
Here are some pictures. His shop is on the internet on URL http://www.p-specialist.nl
An additional note: there is a design issue when you consider that the arm moves up and down (pivots) and the bolt is fixed. That may and will cause one nut to loosen, and the other to tighten over time, causing either cracking sounds or sloppy steering. What I did is add M12x1.5 (fine pitch) nuts to lock the M12 stopping nut in place so that it can not easily move (rotate).
regards
Theo