Keeps shredding belt

[Pryorrides]

2000 LC 2uz-fe V8. Buddy brought it to me with clickity clak serpentine belt noise. I think okay, idler or tensioner. As Im backing it into the shop it throws the belt. Upon inspection belt has removed itself from the passenger side. I notice that the PS pump pulley is packed with belt material (first pic) The truck appears to have a relatively recent idler pulley replacement. So maybe they had a seized pulley.

When it threw the belt it dont not actually break the belt in half. Just the forward most rib broke and for some unknown reason it decided to jump off the pulleys.

Here is a weird part all the pulleys except the alternator feel smooth and free. Alternator spins but its very sluggish with a slight bearing noise. Replace Alternator and belt. Clean rubber debris off of pulley. Re-assemble clicking is gone. I let it idle 20-30min. All good? No.

Buddy reports he is driving the truck, traction control light (and/or other lights) blinks and he pulls over and hears claking. He calls me and I respond to find the belt is still holding but the forward most rib is busted and a loose partially attached piece of belt is whipping around causeing the clicking noise.

Now I am perplexed. As a domestic car experienced wrench. I cant think of any car I have seen just throw belts without obvious bearing damage since the age of V-belts.

New belt and alternator has the correct number of grooves. Every pulley spins smooth and free. Customer reported that he drove with AC on for appropriately 45min-1 hour before problem .

I am thinking tensioner spring weak or maybe AC compressor clutch being worn enough to allow it to contact belt (?)... Is that even a thing? The metal hub on the AC clutch appears to be oversized enough that it could theoretically contact the forward most edge of the belt if say the clutch material had worn down enough. But I am not sure if that is even possible. Never seen a problem like that before.

I am going to dig into this further, but I know these motors are notorious for belt problems, so I am just fishing for leads.

 

[3_puppies]

I know these motors are notorious for belt problems, so I am just fishing for leads.

these engines are not known for belt issues,
fan bracket?

 

[excessive]

any of the pulleys bent or something? This isn't a common issue

 

[vipergrhd]

Something is out of align possibly the P/S pump, but you will need this tool to find out.

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[3_puppies]

is this a new problem?
is it a new rig to buddy?

I was also thinking maybe a clamp is turned and rubbing on the belt, but can't think what might be rubbing on the fan side of the belt

 

[OEMGUY0720]

I am positive one of the pulleys that the serpentine belt passes is either crooked, loose bearing or misaligned.

 

[duowing]

In the event someone has replaced the Tensioner pulley bearing, it is very easy to bend the pulley when driving out the bearing.

 

[Mike NXP]

New belt and alternator has the correct number of grooves. Every pulley spins smooth and free. Customer reported that he drove with AC on for appropriately 45min-1 hour before problem .
>> What is the belt part number and/or post the length of belt here so we can compare to what length should be

I am thinking tensioner spring weak
>> You can feel for this easily when you remove the belt. How did it feel, it usually does a good job of putting up a fight. Even with a breaker bar on there, I am careful not to let it go or else it will kick back and bust my knuckles
>> If it feels crusty or doesn't have a good fight left to it , replace it. OEM only

or maybe AC compressor clutch being worn enough to allow it to contact belt (?)... Is that even a thing? The metal hub on the AC clutch appears to be oversized enough that it could theoretically contact the forward most edge of the belt if say the clutch material had worn down enough. But I am not sure if that is even possible. Never seen a problem like that before.
>> Probably not, you would see black belt rub marks on AC .
>> Does the AC work?

I am going to dig into this further, but I know these motors are notorious for belt problems, so I am just fishing for leads.
>> Motors are not*** notorious for belt problems .
--------

We also have a fan bracket hiding from plain view. Lots of reports of them failing, some with just noisy bearings others have had the bracket give out and do damage . That being said you would most likely see the fan / fan clutch wobbling when viewing from the side of engine and test running.
-----

So you removed the belt, tested all the pulleys and they all check out except the alternator. New alternator goes in and the problem goes away for an hour then comes back with a vengeance and also throws a VSC light ?

What other work has been done to this rig?
*** When did the problem start, it was doing fine up until all the sudden the belt got chewed up?

 

[2001LC]

Vane pump pulley full of belt debris. I'd look there. It may be vane dragging when hot.

Thread 'Steering Flush & Cleaning'

Mar 29, 2016

Cleaning power steering reservoir and flushing it's fluid. Keeps Vane pump and rack & pinion in top condition.

These step will help you get, a better idea on how to.

1. Power wash reservoir & hoses using a degreaser, before starting service. Makes for cleaner job. Repeat, once all done with servicing/flushing.
2. Release hose clamps from hoses of reservoir, sliding them down the hoses a few inches. Do not remove hose yet, just insure they turn freely on reservoir nipples.
3. Pull reservoir out of holder. You'll need to release/bend clip outward, on outside of holding bracket...

• 2001LC
• Replies: 329
• Forum: 100-Series Cruisers

• 

 

[Pryorrides]

What is the issue with the fan brackets on there? Do the bend or what?

 

[Pryorrides]

The

New belt and alternator has the correct number of grooves. Every pulley spins smooth and free. Customer reported that he drove with AC on for appropriately 45min-1 hour before problem .
>> What is the belt part number and/or post the length of belt here so we can compare to what length should be

I am thinking tensioner spring weak
>> You can feel for this easily when you remove the belt. How did it feel, it usually does a good job of putting up a fight. Even with a breaker bar on there, I am careful not to let it go or else it will kick back and bust my knuckles
>> If it feels crusty or doesn't have a good fight left to it , replace it. OEM only

or maybe AC compressor clutch being worn enough to allow it to contact belt (?)... Is that even a thing? The metal hub on the AC clutch appears to be oversized enough that it could theoretically contact the forward most edge of the belt if say the clutch material had worn down enough. But I am not sure if that is even possible. Never seen a problem like that before.
>> Probably not, you would see black belt rub marks on AC .
>> Does the AC work?

I am going to dig into this further, but I know these motors are notorious for belt problems, so I am just fishing for leads.
>> Motors are not*** notorious for belt problems .
--------

We also have a fan bracket hiding from plain view. Lots of reports of them failing, some with just noisy bearings others have had the bracket give out and do damage . That being said you would most likely see the fan / fan clutch wobbling when viewing from the side of engine and test running.
-----

So you removed the belt, tested all the pulleys and they all check out except the alternator. New alternator goes in and the problem goes away for an hour then comes back with a vengeance and also throws a VSC light ?

What other work has been done to this rig?
*** When did the problem start, it was doing fine up until all the sudden the belt got chewed up?

The belt was 88.5 inch. I bought the cheap belt at the parts store because they wanted a ridiculous price for a good one. Plan was to order a high quality one and keep the cheapo for emergency.

All of the debris in the pulley grooves was cleaned out and I just made sure the rest of the pulleys were cleaned out. It did have some more belt debris in the other pulleys, but nothing like in the picture. Im not sure if all that was in there before but it does appear to have a fairly new idler pulley so that makes me suspect it had failed previously.

The tensioner feels sufficiently strong and smooth in operation. I can barely move it with a hand ratchet, have to use a breaker bar to remove enough tension.

I tried free spinning and rocking all the pulleys. Everything spins smooth with no rocking. The PS pump has about an 1/8" in/out shaft play which after doing a search seemed normal.

AC works. Truck is basically a 3rd vehicle that doesn't get driven much.

What I was meant when I commented that these vehicles are "known to have belt issues" was they are known to have pulley issues.

 

[aztoyman]

Any chance the belt is routed wrong? Not usually, but "Sometimes" they will still go on.

As mentioned, verify pulley alignment. If a spacer got dropped or something while bolting components on , one item could be shifted out of alignment. Good luck with it.

 

[3_puppies]

What is the issue with the fan brackets on there? Do the bend or what?

the fan bracket is a shaft that has 2 sealed bearings, after many, many miles they will start having some play in them, if any play at all, replace it
they can let loose and send the fan and fan clutch into the rad.
if the fan bracket is removed and there is any sign of oil/grease seepage on back side of bracket at bearing, replace it

What I was meant when I commented that these vehicles are "known to have belt issues" was they are known to have pulley issues.

pulley issues on a 2UZ? not that I know of, any proof?

as @2001LC stated, the PS pump causing issues when warm is a good suggestion

 

[Pryorrides]

This truck is chewing the forward most rib of the belt and eventually just walking the belt off the pulley. I reinstalled the previously damaged belt, bur with the undamaged portion of the belt towards the front. I did just so I could watch the belt work without destroying a new belt.

In looking at these pictures and video, pay no mind the portion of the belt closest to the engine block, about 1/4 of the length of the ruib closest to the block has seperated from the belt and has been trimmed off so that its not whipping around inside the engine bay.

This is the belt routing I used

Here is how everything looked after installation but prior to starting

Post continued below...

 

[Pryorrides]

Here is what happened upon start up slowed down to 1/4 speed.



As you should be able to see the belt almost immediately jumped one rib forward and began to walk off the crank pulley.

 

[Pryorrides]

Note that I did this process twice and got the same result both times.

 

[Pryorrides]

pulley issues on a 2UZ? not that I know of, any proof?

Seriously, are you joking? Everyone I know of who have any experience with these know that they end up with bad or clicking idler/tensioners. There is a plethora of threads on here about finding squeaking, clicking noises from the belt drive. Apparently the fan bracket has an issue too. People on here recommend changing them when they aren't even bad if you happen to have to remove them for other repairs.

 

[aztoyman]

If it's the crankshaft it's walking off, wouldn't it be the water pump that would be what is routing it off the crank pulley? It rotates clockwise so the crank pulley would be pulling it off the water pump pulley. (If that is the water pump above and slightly driver) Or is my thinking completely off ??

 

[Pryorrides]

The water pump is timing belt driven and not visable.

I'm suspecting that the tensioner is worn but not in the typical manner of a bad bearing or weak spring.

I am not sure how the inside of the tensioner assembly looks but I made this crude drawing to show my suspicions. Excessive play in the red area would allow the arm of the tensioner to rock up and down. If you watch the video the belt first appears to walk back towards the engine and then to the forward edge of the tensioner pulley. Also I assume it would be hard to detect this play with the engine off since the tensioner is under spring pressure.

 

[aztoyman]

I was using your belt diagram as a reference. I looked up belt routing images for your engine and the was same diagram but labeled. That pulley was labeled a WP. Guess not.

I was just trying to determine what would walk it off the crank pulley and based on the clockwise engine rotation (looking from front) that pulley before it would get the belt pulled from it by the crank. If it's off somehow, it could guide the belt off the crank pulley. Just my thought on it. Maybe not.