Where can I order a custom serpentine belt for HO alt?

[cfox10 10+ year member]

Finally got around to installing the belt. It was very tight but I got it on. My only concern is the bounce I get on the pulley, is it something to worry about?

Yes, you could break the tensioner, belt, etc.

Is the alt new? Could be the bearing, pulley, or something else isn't aligned well?

 

[wew lad 5,000+ posts]

Finally got around to installing the belt. It was very tight but I got it on. My only concern is the bounce I get on the pulley, is it something to worry about?

what do you mean bounce? if its the tensioner moving back and forth that means its doing its job, if its the actual belt flexing thats a sign of a bad belt tensioner (or equipment on the serp belt, like an a/c compressor going bad, or a bad bearing although rare) and it needs to be replaced

 

[West1 10+ year member]

Yes, you could break the tensioner, belt, etc.Is the alt new? Could be the bearing, pulley, or something else isn't aligned well?

Yes, brand new alt. When I put the belt on, I had to pull the tensioner really hard to slide the belt on. I think there might be to much tension, not really sure. Belt looks lined up, nothing else seems to be moving or wobbling out of the ordinary.

what do you mean bounce? if its the tensioner moving back and forth that means its doing its job, if its the actual belt flexing thats a sign of a bad belt tensioner (or equipment on the serp belt, like an a/c compressor going bad, or a bad bearing although rare) and it needs to be replaced

The arm that we move to get the belt on jumps up and down while at idle. The belt before (which had like 100 miles on it) would move but very little. Seemed reasonable since the springs on the tensioner would allow it to move. If I had to guess, I would guess the tensioner bounces 60-80 degrees of a circle. Stock tensioner, the only thing replaced was stock alt and new smaller belt

Part: 7PK2190

Should work for your needs.

Edit: Dayco part # 5070862

I will see if I can run a video later this afternoon.

 

[West1 10+ year member]

I would double check where your tensioner is at when installed. They have a range they are supposed to be in, and if it was a tight fit, you may be putting too much tension on the pulleys, which could potentially damage them. I ran into the same problem as you and the only option I could find was a tight fit as well, but I still had a little play on the belt so I thought I was good. Well, it actually wound up bending the pulley on the alt, which caused it to break right off. The belt, being intact, didn't just get spit out like a broken belt would. Instead it got wrapped around components, broke the tensioner, destroyed idler pulley, and did some damage to my ground cable, fan shroud, and fuel line. After that, I found out what the acceptable range of travel for the tensioner was and shopped around until I found a belt which put the tensioner in that range.

Crap, just seen this. I might try and put the stock belt on and see how it goes. Luckily I left the new belt for stock alt at home 20 miles away //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

 

[cfox10 10+ year member]

May not have needed a smaller belt. Or the pulley type is different now. Either could cause the issue.

Before you put the other belt back on start it up without a serp belt and see if you have any unusual movement causing vibrations. Is it an adjustable tensioner or spring loaded? If adjustable you'd need to deviate from the stock pressure and adjust for a slightly smaller belt.

 

[West1 10+ year member]

May not have needed a smaller belt. Or the pulley type is different now. Either could cause the issue.
Before you put the other belt back on start it up without a serp belt and see if you have any unusual movement causing vibrations. Is it an adjustable tensioner or spring loaded? If adjustable you'd need to deviate from the stock pressure and adjust for a slightly smaller belt.

I'll have a look in a few. I believe spring but I need to confirm.

 

[West1 10+ year member]

Went out to try and get a vid, sun is to bright. Cracked up the engine and the pulley was not moving at all. Im a little confused now. And yes it is spring loaded.

I cant see the arm range/gauge. I'll need to take her for a wash and see if it cleans up enough to see the range.

 

[wew lad 5,000+ posts]

if its happening when the alternator is loading down its normal, you'll see that a lot on multiple alt set ups when the bass hits and the alts get loaded down the tensioner tightens to maintain no slip. same on supercharged motors