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!

[QB93Z]

Thanks for posting the picture Charlie. And thanks to Charlie and Dan for retrieving all the tools I dropped in front of the engine while doing the repair.

My failure was a frozen bearing on a stock, plastic pulley with at least 60,000 miles on it. I have not changed it since I bought the car. This is the second stock pulley bearing I have had fail. The first was on my 1990 ZR-1 and was a few years ago.

This is why I carry a spare pulley and belt when I travel. The repair is straight forward and I can get back on the road easily. It helps to have a long 18mm combination (open end-box end) wrench to reach the tensioner bolt. It is harder to get the bolt with a socket wrench.

The only problem is the engine is HOT and I got a couple of burns this time. Even with gloves on, you have to reach in among the coolant piping. I have added heat resistant sleeves to my travel tool box.

Jim

[Dynomite]

Originally Posted by QB93Z

Thanks for posting the picture Charlie. And thanks to Charlie and Dan for retrieving all the tools I dropped in front of the engine while doing the repair.

My failure was a frozen bearing on a stock, plastic pulley with at least 60,000 miles on it. I have not changed it since I bought the car. This is the second stock pulley bearing I have had fail. The first was on my 1990 ZR-1 and was a few years ago.

This is why I carry a spare pulley and belt when I travel. The repair is straight forward and I can get back on the road easily. It helps to have a long 18mm combination (open end-box end) wrench to reach the tensioner bolt. It is harder to get the bolt with a socket wrench.

The only problem is the engine is HOT and I got a couple of burns this time. Even with gloves on, you have to reach in among the coolant piping. I have added heat resistant sleeves to my travel tool box.

Jim

Hi Jim ........Your pulley(s) that failed were stock pulley(s) rather than the Tensioner Aluminum Pulley Locobob had fail. Great Photos...... and that was one reason I went to the Aluminum Pulley as the Bearing is easy to replace.

It still appears like a Fatigue Failure of the Aluminum Tensioner Pulley as Phil suggested. If no other type of interference or bearing failure is found by Locobob.

I also have the Water Pump Aluminum Pulley which has no belt retaining ridge making it much easier to remove the Serpentine Belt (back of belt rides on pulley) from that Water Pump Aluminum Pulley first.

I did modify the 18mm combination wrench heating and bending the box end straight making it much easier to use the box end on the Tensioner 18mm Bolt.

[Paul Workman]

Originally Posted by QB93Z

My failure was a frozen bearing on a stock, plastic pulley with at least 60,000 miles on it. I have not changed it since I bought the car. This is the second stock pulley bearing I have had fail. The first was on my 1990 ZR-1 and was a few years ago.

This is why I carry a spare pulley and belt when I travel.
Jim

Hmmmm... Thanks 4 the tip, Jim! I carry a belt - never thought about a pulley. (Course...where does it end?? (spare parts, I mean...)

[Dynomite]

Originally Posted by Paul Workman

Hmmmm... Thanks 4 the tip, Jim! I carry a belt - never thought about a pulley. (Course...where does it end?? (spare parts, I mean...)

You can preventively maintain it at home or carry spare parts on the road

[Paul Workman]

Originally Posted by Dynomite

You can preventively maintain it at home or carry spare parts on the road

Yup! Totally agree - like changing oil or brake pads, or alternators too, for that matter. Mine died at around the mid 40k miles. So, mebby it would be a good idea to change them out at about 40-50k miles as a matter of routine. But, non-OEM parts are "...like a box of chocolates. You never know what you're going to get!"

[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.