Vintage Mustang Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
4,193 Posts
Discussion Starter #1
Hi folks,

Some of you may recall, I've posted a couple times about a new "swish-swish" sound coming from my engine. It's only been since I installed a new water pump, flex fan, and fan belt (amog other things).

Could it possibly be the new belt - could I have it too tight? The alternator was positioned all the way at the end of its bracket with the old belt, so it had obviously stretched over the years. It sits a couple inches closer in with the new one. I didn't even use a pry-bar to tighten it.

What's the rule of thumb for adjusting the tension on a new fan belt? Could a too-tight belt result in my new swishing sound?

Thanks!
 

·
Registered
Joined
·
21,263 Posts
You should have about 3/8" deflection in the belt. If it's real taught, you'll trash the water pump, alt and place a heavy load on the top main bearing in the front.

The belt needs only to be tight enough so it doesn't slip.
 

·
Registered
Joined
·
4,193 Posts
Discussion Starter #3
Thanks Tom.

I stepped outside and losened the belt, and I do believe the mystery sound is gone - Of course, now I have the squeal of a too-loose belt! If it ain't one thing, it's another! I just need to find the comfortable medium.

Thanks again!
 

·
Banned
Joined
·
1,565 Posts
It's pretty tough to make it "too tight" by hand. I would check to make sure one of your alternator bearings isn't going bad as well.
 
1 - 4 of 4 Posts
Top