generator belt vs alternator belt

G

Grampy

Member
Hi All,

I changed over to an alernator (it has the smaller pulley) and the belt seems to have too much play - probably more then an inch. I have the alternator adjusted out as far as it will go on the new support bracket.

Everything works fine - water pump is turning with no slipping, alt is charging up to 30 amps then working down to 0 amps - everything is working fine. Just the belt has a lot of movement!

Is there a different, shorter, belt for use with the alternator?

Thanks for the help.
 
Time will tell if its too loose to run, but for now if its charging fine, I'd leave it alone. If you can snap the throttle open and get no squeals, its prolly fine. If the battery needs a heavy charging you may find it slipping a bit. Try it out for a while and see. Mine seemed a tad loose but I have no troubles with it so far.
 
The standard for V belts on alternators was to have the belt tight enough that you could not spin the fan blade on the alt. If you tightened to factory spec with the belt tension tool then you would have it tighter. When it was slightly loose the belt squealed with heavy load.

The standard for the A is to be so loose that you can turn the pulley with your finger. I have seen on alt so loose the fan would spin with my pinky finger.

Something tells me that you are not getting the alt to really output a heck of a lot reliably when installed on the A. The A does not need much so it is ok.
 
Don't get the belt too tight, or you could ruin your water pump.

If it's working without squealing, you are going to be ok. If you're worried about being stuck, you could either notch the adaptor that bolts to the front timing cover that pushing the alt out, or take your belt to Autozone or something equivalent and tell them you want a belt slightly smaller than the one you are showing them.
 
You can obtain a "notched" belt from your local modern day parts or Napa dealer. This type of belt will bend around a smaller diameter, and yet does not apply excessive tension that will ruin your water pump bearings.
 
The "H" style alternator brackets have two adjustment points. You can adjust it where the bracket mounts to the alternator and where the bracket mounts to the timing cover, unlike the generators which are only adjustable at the timing cover point. With these two points you literally have 45 degrees of adjustment, from the block to the water inlet.
 
My Alternator belt has almost 1 inch play and I can turn the alternator pulley by hand...is this too loose? Forgive me if this is a dumb question but I am new to Model As. My Les Andrews book Vol II does not address tighness. Greatly apprecaite guidance.
 
Better loose than too tight. If it's not squealing, alternator pulley is not getting hot, and its charging...good enough.
 
Steves46 said:
My Alternator belt has almost 1 inch play and I can turn the alternator pulley by hand...is this too loose? Forgive me if this is a dumb question but I am new to Model As. My Les Andrews book Vol II does not address tighness. Greatly apprecaite guidance.
Click to expand...


It's a little loose, 1/2" should be good.
 
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