I had my recently acquired 1978 SC in for alignment and height adjustment today at a reputable tire and alignment shop. No trouble with the front but they could not move the rear. Apparently the "king nut" that turns the splines is frozen and won't budge. Any experiences/solutions?

 

Hi:

Hmmm,...your question is somewhat cryptic,...

Hopefully, you can clarify,.....

The rear ride height is changed by removing and re-indexing the torsion bars on their splines (dissimilar on each end). There is no "king nut" in the rear suspension.

Your SC has 2-piece, adjustable rear spring plates that have a narrow range of movements for small corrections in ride height and corner-weight. Those two bolts that hold the two pieces together can get corroded over time and require some "persuasion" to move. I use a professional-grade penetrant, some patience, and air tools.

If you look at the excellent Bentley manual for the 911SC, you'll see what I'm talking about,...