[PIC/VIDEO]: Serpentine belt tensioner markings. What does this mean? Squeak noise (1 Viewer)

[l3n0x]

Bit unrelated, but on the 1HD-FTE we don't have an automatic tensioner... I was wondering if anyone knows how to properly tension the belts (apart from buying a tension gauge), because I just can't get it right. I do it up when I feel it should be fine, but then it randomly squeaks on cold mornings. I don't want to overtighten it either and risk of damaging the bearings.

 

[KFunk740]

Dude, take a few minutes and check your pulleys yourself before buying parts and digging in over your head, and don't rely on that mechanic's word.

When the engine is cold, take the tension off the serpentine belt and slide it off, and then spin all the pulleys by hand. Spin them each and see if they feel smooth or rough. Then shop for parts if necessary.
Don't do it when its hot. Bearings tend to loosen up once they get moving for a while.

 

[Pyrenees]

From what I understand, it should spin somewhat freely but not have that gritty/rattly feel, correct?

My top idler had that kind of loose rattling noise and would keep spinning forever. I swapped it with a new OEM one in the hopes that it would fix the squeak (besides, it felt like junk to me).

 

[KFunk740]

Luckily, not all of them should be bad, so you should have a few others for comparison. Once you feel a few good ones and bad ones, you'll know. You could have a brand new idler pulley standing by anyways for comparison, since its the cheapest and easiest to swap.
There shouldn't be much resistance at all when you try to spin it, and once it gets spinning it should spin smoothly and silently. If it takes a lot of force to get it spinning, thats a bad sign. Also, if it feels way too loose compared to a new one, thats a bad sign. If it wobbles side to side, thats a bad sign. If it feels gritty/noisy, thats a bad sign.
Bearings can fail in multiple ways. They can grind to a halt until they completely seize and rip the belt off. Or, they can just completely wallow out all the metal until they flop around everywhere and eventually throw the belt off.

 

[Dad Wagon]

Mine was similar last winter, and the fan bracket bearing went out in our first cold spell this year. I’d suggest replacing the tensioner, idler, fan bracket, and belt all at the same time. I used Gates parts from Rock Auto for all of it - only came out to about $170.

 

[Pyrenees]

I'll have to pull the belt this weekend and spin the pulley compared with the new-a few-thousand-miles-ago top pulley.

How much extra work is the fan bracket once you're already at the tensioner? The tensioner + pulley costs the same as the pulley so I'd just do both.

All the fan bracket horror stories are keeping me up at night

 

[Dad Wagon]

It takes several hours, unfortunately, but isn’t very challenging (getting the fan clutch nuts off is always the fun part, just borrow a fan clutch tool from the parts store ahead of time). Nearly the same effort as a TB swap, so if you have any reason to replace that, have the parts on hand. My TB looked essentially new, but I went ahead did a few other clean-up things while I was in there (VC gaskets, coolant flush, thermostat, heater tees, etc) so I had mine down for a few nights of work, but I’m much more confident in the truck through the winter now. The belt/etc. is now totally silent, too!

 

[ClassyJalopy]

My fan bracket decided to fail earlier this year. It sounded a lot like yours in the beginning and then it got louder from there.
Getting the fan bracket out required basically dismantling the face of the engine so I took that opportunity to replace the timing belt as well.
I agree with others, take the belt off first and spin the alternator, tensioner, steering pump and fan bracket by hand - it will be kinda obvious if any one of those are making this sound.

 

[2001LC]

New or Good pulley bearings will not free spin much at all. You'll barley get one revolution. Bad bearings will free spin a long time, if they're not frozen.


I found the notches on tensioner assembly to indicate belt health, very unreliable.

 

[Pyrenees]

New or Good pulley bearings will not free spin much at all. You'll barley get one revolution. Bad bearings will free spin a long time, if they've not frozen.


I found the notches on tensioner assembly to indicate belt health, very unreliable.

That video is EXACTLY what my top idler pulley was like before. It spun forever and ever.

 

[2001LC]

Idler pulley:
I use new Toyota OEM more than any other when replacing. I do take belt off pulley to replace. By turning tensioner pulley bolt CCW and remove belt from tensioner pulley. If belt is still on tensioner, it is to easy to cross threading idler bolt during assembly. If you can remove and install idler pulley easily without taking belt off tensioner. Your tensioner is likely shot.

Tensioner pulley:
I just press in new tensioner bearings, provide tensioner has good spring tension. How do you tell. Well it's a judgement call. A brand new tensioner assembly will bit your finger off. Slapping your socket wrench or breaker bar again fan clutch, as you release after turning CCW to remove belt. A very bad one will need your help turning back CW to hold any tension on belt. Remember, the tensioner pulley's 14mm bolt is a CCW (left hand) thread.
Here just one method I use to press old bearing out.


In the video I'm using old bearing to press in new. It's even better to use a socket that only presses on outer race of bearing.


I've used National 203-ff and NAPA 6203-2RSJ. NAPA seem to last a littler longer.

 

[Pyrenees]

Sigh. I can't get this resolved. New video attached below, but it's the same thing. This time I replaced the tensioner+pulley and the serpentine belt, all directly from Toyota.

-top idler pulley, OEM
-serpentine belt (twice, first wasn't OEM)
-tensioner unit and idler pulley, OEM
-timing belt was replaced with Aisin kit 10k mi ago

I think the original serpentine tensioner was OK but the bearings on the idler pulleys were very gritty, so I don't feel bad about replacing them. Spinning everything else by hand (PS pump, alternator, fan bracket, AC compressor), the bearings feel normal. no wobble, grittiness or looseness. It doesn't matter whether the AC compressor is on or off.

Part of me worries that this could be a defective roller from the Aisin TB kit or the fan bracket, but I've already thrown a couple hundred bucks at the obvious-seeming stuff (gritty idlers, etc) only to get nowhere. So I'm hesitant to start ripping stuff out unless I'm sure.

One clue I have is that the previous owner replaced the serpentine belt (with the previous one, non-OEM) due to a squeak. So perhaps this has nothing to do with my Aisin TB kit. Who really knows.

This ONLY happens when it's less than 40 degrees outside, ONLY on the first cold start of the morning and ONLY lasts a minute or less.

But I can't stand it.

 

[kruisinkid]

Ac clutch bearing i would guess. But any part that spins that is original to the truck is suspect. Theres a thread with a jap bearing part number you can get off amazon. Otherwise get the garden hose out and start listening

 

[abuck99]

Climate A/C, defrost, fan off when your assessing the noise.

Fan clutch itself could be the culprit if its original ( I found my bearing weaping at 195k). Alternator could be another place to look especially in dusty conditions and or after a number of water crossings. Stethoscope can be helpful to diagnose or locate.

Spinning pulleys alone doesn't really reveal all potential pulley issues- they can spin freely and still be worn. Also need to try and check for lateral play or any movement: up/down, in/out.

 

[2001LC]

If you have serpentine belt off, on cold morning pre warm up, and no squeal. Than it's not the timing belt area.

Fluid clutch, fan bracket or vane pump.

Have you flushed the power steering and cleaned the screen in reservoir. Mobil MV full synthetic ATF one is my favorite for power steering. If regular power steering fluid used in reservoir, than vane pump doesn't like cold. If screen clogged it doesn't like the cold. Old and tried it doesn't like the cold. But until the seal at front of vane pump leaks, they tend to be okay.

Turning steering wheel as sound happening may yield clue. Turn on A/C may also. Keep in mind these load the belt.

You're getting and early warming. They reveal themselves in cold. But I'd not be overly concerned.

BTW: Sometime mechanic (pros & shade tree) install idler pull backwards. It does matter.

 

[Hugh Heifer]

Sounds a bit like mine and I am pretty sure mine is the AC. Has been doing it a long time.

 

[Pyrenees]

get the garden hose out and start listening

My garden hose doesn't talk, man.

But I assume you mean put one end close to the noise and the other end to my ear?

Stethoscope can be helpful to diagnose or locate.

I have one of these, I should probably use it.

Have you flushed the power steering and cleaned the screen in reservoir.

Nope, I've been doing the lazy turkey baster method at each oil change with whatever-spec regular ATF they recommend. I'm a little paranoid about making it leak, because so far, it doesn't.

 

[sje1124]

I’ve got something similar going on right now. Thinking it may be my fan assembly that needs to be replaced.

 

[phatdragon]

Sigh. I can't get this resolved. New video attached below, but it's the same thing. This time I replaced the tensioner+pulley and the serpentine belt, all directly from Toyota.

-top idler pulley, OEM
-serpentine belt (twice, first wasn't OEM)
-tensioner unit and idler pulley, OEM
-timing belt was replaced with Aisin kit 10k mi ago

I think the original serpentine tensioner was OK but the bearings on the idler pulleys were very gritty, so I don't feel bad about replacing them. Spinning everything else by hand (PS pump, alternator, fan bracket, AC compressor), the bearings feel normal. no wobble, grittiness or looseness. It doesn't matter whether the AC compressor is on or off.

Part of me worries that this could be a defective roller from the Aisin TB kit or the fan bracket, but I've already thrown a couple hundred bucks at the obvious-seeming stuff (gritty idlers, etc) only to get nowhere. So I'm hesitant to start ripping stuff out unless I'm sure.

One clue I have is that the previous owner replaced the serpentine belt (with the previous one, non-OEM) due to a squeak. So perhaps this has nothing to do with my Aisin TB kit. Who really knows.

This ONLY happens when it's less than 40 degrees outside, ONLY on the first cold start of the morning and ONLY lasts a minute or less.

But I can't stand it.

That is one angry squirrel, you just need to bang on the hood in the AM to get him out prior to starting the rig.

 

[2001LC]

Take off your serpentine belt like in post # 29 video above. Inspect the pulleys.
[PIC/VIDEO]: Serpentine belt tensioner markings. What does this mean? Squeak noise