Originally Posted by
eschlwc
- hanger bolt (3876). mine has a tiny hole for the spring. the bolt is hollow and threaded inside to fit the screw described below.
That's not the hanger bolt; that the upper pivot tension pre-load bolt. The hanger bolt is
#2551A , and it installs from the back side of the hanger.
questions:
- how do i load (tension) the spring? or do you pre-load the spring at all?
You only need to reset the pre-load if the backing plate
#3563L was removed allowing the pre-load to be released. In that case you insert an allen wrench into the pre-load adjustment bolt
#3876, twist it to apply pre-load, and install the backing plate
#3563L to hold the pre-load.
- is it wholly necessary for the spring to be engaged for the derailleur to work adequately?
Yes.