Pulley Failure

[Locobob]

Well I pulled the belt off and the pulley seems to spin freely by hand... although that doesn't mean it doesn't perform differently under load. The belt doesn't look terrible, its a little chewed up in a couple of spots. I need to check my notes for the belt size, I have the underdrive pulley set from SRP. I have Gates and Dayco pulleys available locally. I believe Gates is supposed to be the gold standard but with all the outsourcing going on who knows anymore. I did rebuild the tensioner a few years ago because it was chattering badly, I haven't seen any sign of it bouncing around since so I'm guessing that part of the assembly is okay.

[Dynomite]

Originally Posted by Locobob

Well I pulled the belt off and the pulley seems to spin freely by hand... although that doesn't mean it doesn't perform differently under load. The belt doesn't look terrible, its a little chewed up in a couple of spots. I need to check my notes for the belt size, I have the underdrive pulley set from SRP. I have Gates and Dayco pulleys available locally. I believe Gates is supposed to be the gold standard but with all the outsourcing going on who knows anymore. I did rebuild the tensioner a few years ago because it was chattering badly, I haven't seen any sign of it bouncing around since so I'm guessing that part of the assembly is okay.

Did you modify the Tensioner such that the pulley inner hub was not in contact with the tensioner at any place? Take a close up photo of the Aluminum Pulley belt surface. Also a close up photo of the failed surface.

Was the Pulley Bearing Snap Ring on the outside or toward the engine?

[Locobob]

Originally Posted by Dynomite

Did you modify the Tensioner such that the pulley inner hub was not in contact with the tensioner at any place? Take a close up photo of the Aluminum Pulley belt surface. Also a close up photo of the failed surface.

Was the Pulley Bearing Snap Ring on the outside or toward the engine?

I'll have to take a look at that once I get the tensioner out. I don't recall any modification being necessary. The pulley has multiple holes in it, all around, so obviously it was turning some and then locking up at times.

[Dynomite]

Originally Posted by Locobob

I'll have to take a look at that once I get the tensioner out. I don't recall any modification being necessary.

[Locobob]

Originally Posted by Dynomite

Now that I think about it I may have done that... looks familiar, I think I may have used my die grinder and a sanding drum and beveled that edge

[Dynomite]

Originally Posted by Locobob

Now that I think about it I may have done that... looks familiar, I think I may have used my die grinder and a sanding drum and beveled that edge

If you did that (used die grinder on interference issue) and the bearing is fine now.......we are back to Phil's suggestion (Fatigue). Or..........."your combination of stuff" rebuilt Tensioner.

It sounds from your description that the Serpentine belt was very loose toward the end which means the pulley was not held tight against the belt. But the pulley could spin freely? Maybe you should go back to the "factory Serpentine Belt Tensioner".

[Locobob]

Originally Posted by Dynomite

If you did that (used die grinder on interference issue) and the bearing is fine now.......we are back to Phil's suggestion (Fatigue). Or..........."your combination of stuff" rebuilt Tensioner.

It sounds from your description that the Serpentine belt was very loose toward the end which means the pulley was not held tight against the belt. But the pulley could spin freely? Maybe you should go back to the "factory Serpentine Belt Tensioner".

No the belt was nice and tight, I removed the belt before spinning the pulley. It spins without a load on it but that doesn't mean it would do the same under load. I rebuilt the tensioner about 2 1/2 years ago using the original, some L98 parts, and the aftermarket aluminum pulley. Hopefully that makes it clearer.

[Dynomite]

Originally Posted by Locobob;294244[B

[/B]]No the belt was nice and tight, I removed the belt before spinning the pulley. It spins without a load on it but that doesn't mean it would do the same under load. I rebuilt the tensioner about 2 1/2 years ago using the original, some L98 parts, and the aftermarket aluminum pulley. Hopefully that makes it clearer.

Hi again

When you remove the Aluminum pulley.....
The belt being a bit narrower than the pulley surface.....
See if you can see where the belt track is worn more than the original surface. On aluminum pulleys I have that wear surface is worn less than .005" in about 6,000 miles.

I have no wear on a larger diameter aluminum water pump pulley which also sees the back side of the serpentine belt. When the belt goes around those pulleys the surface of the belt retracts a very small bit wearing the pulleys. I have to check the stock pulleys for similar wear. Or maybe belt slips a bit when starting.

[Locobob]

Got everything apart today, my camber brace makes it kind of a bitch. Here is the worst part of the belt, actually doesn't look terrible.

[Locobob]

More pics of the tensioner and pulley