Door Opener chain/cable tension?

I noticed last night that the chain portion of the chain/cable loop on one of our 15 year old Craftsman garage door openers rattled against the rail when the door was moving and when the door hit the down limit and stoppedthe chain was drooping a little bit over the edge of the rail.
I'm assuming this is due to chain wear and/or cable stretch over the years.
There's a threaded tension adjustment where the cable joins the carriage, but I'm not sure if there's a "right way" to determine how much to tighten it.
Do I just tweak it tighter until the chain stands proud of the rail at all times?
Thanks guys,
Jeff
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Jeffry Wisnia

(W1BSV + Brass Rat \'57 EE)
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That's what I did - including not hitting when the chain is moving. I wiggled the chain back and forth (when fully extended) so that it doesn't hit the rail. No problems since. I lubed it at the same time, including the truck that runs on the rail and it runs a tad quieter now too.
Mike
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With the opener stop at the half way position & the door disengaged from the opener (no load on the carriage) the chain should sag approx 1/2" from the top rail.
If you make it to tight the rail may start to bow and it will cause excessive wear on the drive sprocket shaft bearing.
Doordoc www.DoorsAndOpeners.com
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On Wed, 18 Jan 2006 13:35:10 -0500, Jeff Wisnia

far. You can tell if the rail bows upward in the down postion. If it does not, then go ahead and try to tighten the chain with the dorr part way up so there is just a little slack but not to tight. Best Regards Anthony snipped-for-privacy@yahoo.com
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