Suspension & Steering
Ride Height Adjustment
Thought I'd pass on my experience adjusting the ride height on my '89S4.
Here are a few "tips".
1) The Pro Motion tool (avail. @ Bob Tracey's World of Cycles - Moon Township, PA 412-269-9999, $22.41 delivered) that Ed Ruiz suggested is a must.
2) Before you start, get a full load of fuel - this makes a difference
3) Make certain you are working on a completely level surface - this makes a difference
4) The night before you are to begin, get out that new can of WD40 and be generous. The part that sticks is the area on top of the adjusting nut where it makes contact with the lower spring plate - this makes a BIG difference
5) Take height measurements before you start. (I'm confident that you engineering types know about baseline and all)
6)Get a decent measuring tool - I used an expandable pointer (remember these, before laser pointers) and a tape measure. To convert inches to mm, multiply by 25.4 ie: 6 1/4" = 6.25 x 25.4 = 158.75mm
7) Begin with the corner that is furthest out of spec (or relative to the other corners). This will probably be one of the front springs.
8) If your front is low like mine and you're running out of adjustment capability (seeing more than 5 threads below the nut), you may be able to lower the rear to help you get the front up.
Side line: I made the mistake of beginning with the rears because they looked the most accessible. I was going to bring them up to "new" ride height 170mm. Well, once I got there, I had put so much additional weight on the opposite front, I couldn't adjust to within spec on the fronts. So after working for 2 hrs making 1/8th turns on that friggin' nut on both rears, raising them 10mm, I had to bring them back down to "unload" the front springs.
9) Take a look at what the factory manual says about the 180mm (front) and 170mm (rear) target settings. These are for NEW cars/springs. "downward tolerance can vary by 10mm more" (read carefully as the manual is unclear, the xtra 10mm less may only apply to the maximum setting)
10)Wear gloves - if my knuckles could talk they would be screaming at me. Sometimes the Pro Motion tool slips off the nut while you are giving it "full reverse thrust" (another language lesson for my kids). Also, when pushing the tool, I put a nice blister in the palm of my hand (yes, it was the Pro Motion tool that gave me the blister)- this makes the BIGGEST difference
11)A reasonable objective would be to minimize the height variance on each front corner, then on each rear corner. I was able to acheive this objective, LF - 152.4mm RF - 152.4mm, LR - 154mm RR - 154mm, but I fear that no further adjustment will get me closer to spec, much less "new" ride height. New springs are in my shark's future. Gratefully, Dave Roberts has the antidote for my LRS (low-rider syndrome).
12) Finally, once you think you've got it, take the car out for a little spin; a couple semi hard stops, a couple quick corners, then back home. Re-measure, guess what, bring out that Pro Motion tool and get back at it, you ain't done.
Hey, who said it wasn't fun??
Joe Rausa and "Ray" (sitting higher, but not quite right yet)
Be sure to check out the excellent pictorial ride height adjustment guide at http://www.928.org.uk/height.html
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