Belt tension ?

Theory208 · Jun 11, 2009

(00 Accord ex sedan)- I'm putting the alternator belt back on and don't know how much tension to put on. My manual says-
(Using a fisherman's scale) 22 lbs applied at 90* in middle of belt (a/c to alt), (amount of deflection in belt) new: 3/16''-1/4'' used: 5/16''- 3/8''.
(Same application for power steering belt), (amount of deflection)- new: 7/16''-1/2'' used: 1/2'' -5/8''
I don't have a fisherman's scale (could get one), but was wondering it there is another way to measure it with out it? Thanks

finch13 · Jun 11, 2009

The general consensus is 1/4" belt flex on a 7 in. span of belt and 1/2" belt flex on a 13 in. span of belt. By span of belt, I mean from the A/C to alternator pulley or the A/C pulley to the crank pulley.

Another method is that the belt should not be able to rotate more than 90* in a span.

Theory208 · Jun 11, 2009

I got the belt tension like this-
Tightened the belt (all bolts to spec) just enough to where it would squeal (with out revving). Turned it off quickly.
Loosened all bolts and put one full rotation (clockwise) on bolt to tighten the belt. Re-tightened all bolts to spec.
Revved engine to red-line to see if it would squeal. It didn't so...
Loosened all bolts and eased off belt tension (half a rotation counter clockwise).
Re-tightened all bolts.
I might be able to back off another quarter turn.
I'd imagine a belt that was to tight would defeat the purpose of lighter pulleys, and put more stress on bearings.

HondaLuver83 · Jun 11, 2009

The more you tighten that belt the more your putting stress on your alternator and everything else that belt runs on. Just follow what brandon was trying to tell you

finch13 · Jun 12, 2009

Correct, too tight and you're looking at ruining shaft bearings on the compressor, alternator and/or pump.

Your guestimation at it is fairly close, but I'd be a little more accurate with it as the belt will stretch a bit when it's warmed up and maybe start squealing again.

And I just remembered the correct term for "belt flex"; it's DEFLECTION