jay4runner

Recently replaced a number of things on my 1990 4Runner 22RE (5spd man) including timing chain, cover, oil/water pumps, oil pan gasket, belts and a few other things. After starting to drive it a bit it started making what sounded like a slipping fan belt sound. Assuming it was a belt and finding that the inside belt (alternator) definitely seemed loose I tightened that one up (that particular belt is somewhat painful to adjust). The sound persisted so I then also tightened up the other belt a bit (very easy to adjust by way of the tensioner). Squeeling still happening. So, I had another go at the alt belt and snugged up a bit more (thinking it was still maybe a bit loose). Still squeeling! I am no expert on belt tension, however, they certainly seem snug enough to me. Also, I get the squeeling most of the time I am driving, however, if I am just idling in the driveway and and rev the engine I can't seem to get the squeel (should that tell me anything?). Anyways, does anyone have any ideas/suggestions on what else I might try? Thank you for any tips/suggestions you may have. Thanks!

snippits

Usually when I get the squeal it is from the alternator belt. Not on my 92 22RE truck, but on other cars I have had alternator squeal because the bearing in the alternator was bad.

87yo_ta

I've had this happen when the bearing in the tensioner pulley started seizing up. Easy to replace the bearing w/o buying the entire pulley assembly.

2ToyGuy

^^This.

Having said that, the entire pulley assy, pulley with bearing already pressed in, doesn't seem to cost any more, at least at my local AutoZone than just the bearing.
Either way, it's a very simple procedure to replace.

I know The Book has the specs for the belt tensions, checked with different name brand gauges, but, and this is probably the way wrong way to do it, I honk down hard on the alternator belt. Never had any trouble with it slipping
The book specifies that a new belt, once it's been run at tension for 5 min is stretched, and should be retensioned.
Usually, when I put a new belt on, and honk down on it, it feels like about the right tension the next time I check it, after a run of 5 min or more.
I have a long standard screwdriver, pretty heavy shaft, say 7/8ths the size of a #2 pencil, I use to tension the alternator belt. Yeah, I know, right tool for the job, and all that. When the shaft starts to flex, I figure that's the right tension. Especially on a new belt. It's worked good for me for 30+ years so far, so I'll stick to the "wrong way".

I change my belts, hoses, plugs, and so forth, every spring. I throw the stuff I remove in the back, of the 4Runners, and behind the seat in the pickup. I throw away the previous year's set. In case one of the new items breaks, leaks, cracks, etc etc, I have a "known good" replacement readily available. It's saved my bacon a few times, especially distributor caps. I've gotten some with micro cracks in them, that don't work very well at all. I just pull the bad, new one off, put the good, old one back in, and go get a newer, new one

Just my experiences.
Pat☺

jay4runner

Thanks everyone for the feedback. I don't think i want to tighten that alt belt any more. so will maybe remove the belts and see if any of the pulley are noticeably noisy at all. Have also heard that a bad battery can cause the alt belt to slip (as the alt is overworking trying to charge the battery).

jay4runner

I have removed the top belt (power steering). The pulley on the tensioner does rotate smoothly (at least it seems to) as does the pully on the power steering. However the pulley on the tension does have a tiny bit of play in it. In other words I can move it a bit front to back - not much but a bit. Is this normal or could it be the cause of the noise?

87yo_ta

If I remember correctly the entire pulley assembly wiggles when it it not tightened down. Are you talking about play in the actual bearing itself? The bearing should have no play. I checked mine by removing the belts then tightening the pulley back up and spinning it by hand. I've replaced two of the three in the last 29 years and tested both in the same fashion. :-)

Discombobulated

I recently had the same sort of issue, I checked my tensioner and it seemed fine, when it’s super cold out cold starts sound like a dying weasel with a honey badger killing a cat…warms up its fine, only on super cold mornings. It got so bad I was waking the dead, I chopped the belt and of course it’s gone. Now I’m stuck with getting a belt and guessing on tensioner or compressor, this will be the 6th? I think compressor if I replace it. But what sucks is it only happens when it’s cold….really cold so I can’t duplicate but they are so close to each other it was hard to tell. Oh the joys of a 91 pickup, I love it

Sorry I’m no help, but I would like to know what you find.

jay4runner

It is definitely some play in the pulley itself. So, I guess that is what i must replace. When i look at RockAuto online for my vehicle it shows tensioner pulleys as well as idler pulleys. Which is it? They both look the same on the RockAuto catalog. And actually some of the pulley's under Idler as well as some listed under tensioner note that they are related to power steering. Regardless, I'm assuming it would be cheaper to try and remove/replace the bearing in the pulley - so just need to find one of those.

2ToyGuy

Like I said, a lot of places carry a pulley with a new bearing already pressed in for you. Often, for the same price, or even less, than a bearing alone.

Having said that, the bearing is very easy to press out and in, or just drive out with a small ball peen hammer and large socket. Couple 4X4 wood blocks to set the pulley on, and away ya go.

Good luck. The squealing when cold is usually the first indication of the bearing going bad. When it does that, I replace it, and the belt. Better safe, IMHO.
Pat☺

jay4runner

I have done a fair bit of searching (including on yotatech) for the correct bearing number. It seems clear that the bearing is an NSK 6204. However, there are many different versions of this (denoted by way of different letters after the number). For example some have said it is an NSK 6204DU or 6204DDU, others have indicated NSK 6204V or 6204VV, while others have indicated its a NSK62042RS. So which is it and what do these letters denote? Does anyone happen to know which particular one is appropriate for the tensioner pulley (not idler pulley).

87yo_ta

https://www.bearing.co.il/DGBB04.pdf

87yo_ta

I believe they are the same but to make it easy on yourself what belt has the bad pulley? A/C or Power Steering? The alternator does not use an idler/tensioner pulley.

jay4runner

It is belt #3 - the one that goes over p/s. I don't have aircon so only 2 belts. Just for my understanding is it called an idler pulley or a tensioner pulley? Because it is where you adjust the tension on the belt. And, as i said earlier, when i checked out Rockauto they listed both an idler pulley and a tensioner pulley for the vehicle. Anyways, i did go today to a bearing shop - I had called ahead to see that they had the NSK6204 and they said they did. When i went in they gave me a bearing made by FAG (Korean). I suppose it will be ok. The number is 6204 2RSR C3. What do you think - will it be ok?

millball

Yhat bearing will be fine. 2RS indicates rubber seals, both sides. That's what you want.

When you push in the new one, only bear on the outer race.

2ToyGuy

That's where the large diameter socket comes in. 25 or 27mm, I think it was, but I might well be wrong. Something along those lines, anywho. Matches the outer race almost perfectly. Whether you use a hydraulic press, or a ball peen hammer, it makes sure the rubber seals, or the inner race aren't damaged. Just make sure it stays well lined up on the outer race. Using a press, it'll pretty much stay in position. Using the hammer method, check it before every tap. It doesn't take a full arm swing with a sledge, either. Just some light taps on the socket, with a small-medium hammer, will drive it right on in.

Have fun!
Pat☺

Blueman

An old test to test for belt squeak is to touch it with a bar of soap to see if the squeak goes away.

jay4runner

I feel a bit stupid but I must admit to you all that I now realize this isn't likely a belt (or belt bearing) related issue. I had assumed it was because it sounds exactly like that. However, I have noticed that if i just let the truck sit stationary and rev the engine i do not get any squealing. So, it squeals when i'm driving along and does not fluctuate according to engine revs. I coasted down a bit of a hill today at neutral idle - still squealing sounds just like a belt. Heck, I even shut the engine off for a few seconds while coasting - still getting the sound. Any particular thoughts on what to check?

millball

Disc brake pads have a device that squeals when they are thin,

jay4runner

The squealing is not related at all to applying brakes, so I have to assume that wouldn't be it.