Aftermarket Belt Tensioner Pulley Failure

[Dynomite]

Originally Posted by Locobob

One of the symptoms I had was periodic low voltage at idle. Sometimes I'd be sitting at a red light and the voltage would drop down to like 8-9 and the stereo would shut down. It was an intermittent issue and my thought was this was due to belt slippage, possibly from my leaky A/C system. I had my alternator rebuilt a while back and that made no difference so I eliminated that as the possible source. Now I'm thinking maybe it was the pulley occasionally seizing up and dragging down the belt speed at idle. Guess we'll see once I get that replaced.

Was anything leaking on the serpentine belt?
How many miles on your Tensioner Aluminum Pulley?
Did you modify the Tensioner when you installed the Pulley?

I checked three Belt Tensioner Aluminum Pulley Installations and all is well.
One Tensioner pulley with 6,000 miles. I removed the 6,000 mile Tensioner Aluminum Pulley and checked the bearing which was found had no play and very smooth when rotated.

Originally Posted by Locobob

I have been noticing a silvery oily residue under the air horn and around the general vicinity of the belt. Although I think that is from a leak in the A/C system which is another area I need to address and that could also account for belt slippage.

What is that all about?
Belts and oil do not mix
The problem of an oily belt would be between the belt and the Harmonic Balancer driving the belt and Alternator Pulley, Power Steering Pulley, Water Pump Pulley, AC Pulley getting power from the belt.

Check the Bearing and what is meaning of oily residue?
Even if the belt was oily the Tensioner Aluminum Pulley is free wheeling so I would expect no issues. Spin the Tensioner Aluminum Pulley before you remove the Tensioner to see if any play, resistance, interference.

[Locobob]

Originally Posted by Dynomite

Was anything leaking on the serpentine belt?
How many miles on your Tensioner Aluminum Pulley?
Did you modify the Tensioner when you installed the Pulley?

I checked three Belt Tensioner Aluminum Pulley Installations and all is well.
One Tensioner pulley with 6,000 miles. I removed the 6,000 mile Tensioner Aluminum Pulley and checked the bearing which was found had no play and very smooth when rotated.



What is that all about?
Belts and oil do not mix
The problem of an oily belt would be between the belt and the Harmonic Balancer driving the belt and Alternator Pulley, Power Steering Pulley, Water Pump Pulley, AC Pulley getting power from the belt.

Check the Bearing and what is meaning of oily residue?
Even if the belt was oily the Tensioner Aluminum Pulley is free wheeling so I would expect no issues. Spin the Tensioner Aluminum Pulley before you remove the Tensioner to see if any play, resistance, interference.

I rebuilt the tensioner and installed the pulley about 2 1/2 years ago... probably about 10-15K miles. The belt itself doesn't feel oily so we'll see.
Do you have the same aluminum pulley? Could be I just got unlucky and got a bad one.

[Dynomite]

Originally Posted by Locobob

I rebuilt the tensioner and installed the pulley about 2 1/2 years ago... probably about 10-15K miles. The belt itself doesn't feel oily so we'll see.
Do you have the same aluminum pulley? Could be I just got unlucky and got a bad one.

I think I have the same pulley and someone here said Jim had failure of same pulley but am not sure of that. Did you modify the tensioner for installation of the pulley?

We have to wait to see what you find when you remove the Tensioner.
Before you remove the Tensioner check the Pulley to see if any play, resistance, interference.

The Serpentine Belt is just a bit narrower than the riding surface on the pulley (check that surface for wear compared to the original surface).

It could be a fatigue crack between spokes as Phil Suggests.

[dredgeguy]

Originally Posted by Dynomite

I think I have the same pulley and someone here said Jim had failure of same pulley but am not sure of that. Did you modify the tensioner for installation of the pulley?

We have to wait to see what you find when you remove the Tensioner.
Before you remove the Tensioner check the Pulley to see if any play, resistance, interference.

The Serpentine Belt is just a bit narrower than the riding surface on the pulley (check that surface for wear compared to the original surface).

It could be a fatigue crack between spokes as Phil Suggests.

On the way back from BG Jim had complete failure of the pulley. It locked up and was sawed in half from the belt. Jim, always prepared had a spare pulley and a spare belt in the car and made the repair in a small shopping center in West VA. Repair done in 35 minutes!

[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

[Locobob]

The pulley turns freely and doesn't make any obnoxious sounds, it does feel a bit sloppy however.