GusLight-Rennsport

I have a flaky cruise control, that sometimes works when I hold the stalk,
but then just pops back off. I have taken off the box under the driver
side dash and resoldered any suspicious looking joints, but that did not
fix. Last weekend I decided to attack the servo. When I opened it up I
found some grease on the contact strips at the bottom, & I cleaned them,
but when I put it back together I had trouble figuring out how to
re-attach the large spring around the plastic gear. It slips into a slot
at the bottom, but where does it attach at the top to keep it taut? I
just put it back together, but the shaft just turns left to right and back
with no spring tension. Have any of you had this apart, any thoughts