On Jan 31, 11:40 am, "CsB" wrote:
I have a Craftsman 1/2 hp screw-drive garage door opener. It was
professionally installed in 2003 on a new garage door. Never had a
bit of trouble with it (until now).

In the middle of January, my wife said "the garage door isn't closing
all the way". Sure enough, it stopped about 3-4 inches short of
closing. And, the arm mechanism would bang into the actual drive
housing when it was fully opened.

"Ah, simple adjustment" I thought. I grabbed a screwdriver and
adjusted the travel limits (lower and upper) and it worked fine. For
about two weeks.

I noticed was, again, not closing completely and banging into the
drive housing when opened. I adjusted the limits a second time.
Looked good to me.

Three days later... I notice it's not closing all the way grrrrr...

The problem is happening more frequently. Obviously, my feeble
attempts at adjusting the limits work only temporarily.

Could the opening arm be consistently 'skipping' on the screw drive?
What else could cause the repeating adjustment problems? Anything I
should check before I just call someone to take a look at it?

Thanks!

Mark the position of your limit screws and see if vibration is causing
them to turn on their own.

Well, I guess they wouldn't really be turning "on their own" if
vibration was causing them to turn, but you know what I mean.
Actually, if they WERE turning on their own that would be pretty
scary! g