"Ted Bennett" wrote
After removal and reinstallation[1], the shifters seem to have lost
their clicks in the middle three or four gears.

--
Ted Bennett

I just dug up Sheldon's reply to a similar querry I had a while back:

Gary Jacobson wrote:
I can't seem to get a set of Shimano indexed 8 speed bar end shifters to
index properly.
This is not a question of compatibility, I trust and hope. Not the
Dura-Ace
Vs. Ultegra issue.
The rear deraillure is a Sachs New Success.
Is there a set up trick issue that I haven't figured out?


The casting that mounts into the handlebar has a square fitting. The
adaptor bushing of the shifter has a matching square hole. You may have
it rotated 90 degrees or 180 degrees from the correct orientation.

Sheldon "Been There, Done That" Brown