Hissing drivebelt? - Toyota Nation Forum : Toyota Car and Truck Forums

WhiteRabbit · 01-25-2006, 08:07 PM

put in my new high output alt yesterday and decided to change the drivebelt while i was at it with a good year gatorback one that has ridges cut into it. now when the engine is on and the pulleys turn the belt, i hear a hissing noise, thought it was too tight so i took a look at it. but it was actually loose cause i saw the belt wobbling so i tightened it further following the tension rules in the haynes manual. it still hisses...

is this normal cause its being broken in? or is it something else? doesnt sound like its coming from the alt though.

thanks.

Mike Gerber · 01-26-2006, 05:22 PM

If you still have the old belt, why not put that back on to test out whether the noise is the new belt or not. It should take about 5 minutes to change.

Mike

ag6286 · 01-26-2006, 08:08 PM

^ do that but keep in mind a higher output alt will require more power to turn it therefore the tension in the belt must be stepped up a notch or two in order to compensate for the added force working against the belt

WhiteRabbit · 01-26-2006, 09:45 PM

guess ill try that.

marc780 · 01-26-2006, 10:15 PM

hissing noise? You Might have the wrong belt. OR maybe the belt is off a rib or two. Try a different brand of belt, NAPA makes good ones.

Digger1 · 01-27-2006, 11:27 AM

White,

Now that you mention it, I think I've also noticed the slight hissing noise when I put on new Gator-Back type belts.

It seems to go away after a while. Don't forget to recheck belt tension after the new belt(s) get a few hundred miles on it(them).

WhiteRabbit · 01-27-2006, 01:32 PM

^cool thanks, ill see if it goes away. tension is good.

marc780, ribs are secure and its the right belt =)

Hajoca · 01-27-2006, 03:17 PM

is that the sound of the belt moving air?

ag6286 · 01-27-2006, 04:40 PM

^^ not likely, more than anything is the differing contact on the moving parts, the vibration the friction/rotation will cause (similar to that of a tire, ever notice different tires will give different noises in the cabin? some much more than others). also a new belt is more sticky, so different noises will be cause by that, think of the sound a piece of tape makes when you pull it back quickly.

i think i have a problem reading....

WhiteRabbit · 01-27-2006, 05:09 PM

^i followed the 1/4" slack rule on tightening the belt.

ag6286 · 01-28-2006, 10:11 AM

^^that rule is all fine and dandy 'til you start upgrading parts that require more torque to rotate. more torque means more normal force on the belt is required to keep contact continuous...but as long as you dont here that nasty squeeling you should be fine, give it a couple hundred miles for the initial surface of the belt to wear, after that the noise may go away; if not, as long as everything is working properly...don't fix somethign that aint broke, or try a bit more tension

Digger1 · 01-28-2006, 11:38 AM

Since I can't afford the proper belt tensioning tool (does anyone know of such a tool that is accurate, easy to use, and does not cost an arm-and-a-leg?), I just make sure my belts are not overly tight. As long as they don't squeal, I figure they're tight enough.

Comments?

WhiteRabbit · 01-28-2006, 11:53 AM

^take a straight edge and place it on the belt, then take a ruler and push in the middle of the belt between the pulleys firmly. if the distance between the two pulleys is 7-11 inches, you should only be able to push in 1/4 inch. If its more that 11 inches, you should only be able to push in 1/2 inch.