Fan Clutch Question

[Yooper]

Howdy folks -
For some time now, my truck has been emitting a rather obnoxious squealing sound from the engine whenever I drive through a puddle large enough to splash up on the hood. I have been writing this off to belt slippage and not worrying to much about it because it eventually goes away.

Yesterday I was driving around and hit a couple of puddles and sure enough, it starts singing again. I then proceeded to drive on the highway for a couple of hours, assuming that the wind and drive time would dry the belt up (I was on a trip, not just burning gas ). It did not and the squeal was loud enough that it could be heard in the cab at 65 mph (whenever the rain let up enough to hear anything). Today it was running nice and quiet again.

That got me worrying that it could be one of the bearings in one of my pulleys. Having just replaced the tensioner pulley and bearing, I am fairly certain it is not that one. However my fan clutch/bearing could be a likely candidate. According to my Haynes manual, I am suppose to check the clutch for "excessive play". Having done this, I found that the outside edges of my fan blades will move front to back approximately 1/4". Is this enough to be considered "excessive"?

The belt is about two years old and not showing any signs of unusual wear.

Any help on this one would be appreciated.

Yooper

 

[mkpecor]

it could be the bearing in the alternatore, water pump, power steering pump, check them for play, grab them close to the mounting nut, nuts and push and pull on them, if they are bad the will go in and out. good luck.

 

[Capt Jay]

Run it when it's squealing and put an ear to the open hood. At least you can narrow it down from there. If that doesn't work, start it and start spraying components with a garden hose. Then you can at least find out where it's squealing. After that you can figure out if its a belt or bearing.

 

[Yooper]

Alright, I went out and couldn't find any other pulleys that wiggled at all. So I started soaking different pulleys with water, and couldn't get it to recreate the noise. Great.

So I let it sit for about 10 minutes and then headed into the store. Pulled out of the parking lot, starts squealing on me. Keeps getting worse and worse all the way to the store and all the way back. I parked it running and crawled under the hood. Trying to figure it out by ear, I narrowed it down to somewhere in the center of the engine: tensioner, fan, or crank pulley.

I did notice that it was the worst around 2000rpm. I would be driving at about 3000 and when I hit the clutch and let the engine down to idle, it would get really bad through 2000 and then get better down near idle, but never quite gone. Same story going up through the rpm.

At idle the noise was kind of quite, and even intermittent at times: off for one second, then on for three or four.

I'm lost as to what to try next. Can I spray down my pulleys with WD-40 one at a time until it stops? Then the last one sprayed is the problem, but I don't want to ruin any of the good bearings.

Any more help would be greatly appreciated.

Yooper

 

[Big Jim M]

You stated you have replaced the tensioner bearing... Does that engine have an "idler" pully? If so they have the smallest of the bearings under tension.. I always replace both the tensioner and the "idler" at the same time. They are the cheapest thing to replace.
Big JIm

 

[Yooper]

First of all, I was confused. I replaced the idler pulley and NOT the tensioner pulley, my mistake.

Next, I spent some more time working on it tonight. I started spraying down pulleys with PB Blaster and got almost no result. I hit the idler, tensioner and fan clutch with some oil and now there is almost no squeal at idle, but once you add any rpm it goes crazy.

Next, I pulled off the tensioner pulley and soaked some oil into the bearing. Put it all back together and nothing changed. If anything it is now worse at 2000rpm than it has ever been.

I tried the screwdriver trick for listening to the bolts that hold on the idler, tensioner and A/C compressor (just for kicks) and it does not appear to be coming from any of those. I think my next step is going to be pulling the fan clutch off and checking/replacing that.

If anyone can think of anything else, I would certainly be grateful.

Yooper

 

[Big Jim M]

To be honest with you I have never heard of a fan clutch that squealed. But I'm still learning. However I have heard many of the tensioner and idle bearings make quite a bit of noise.
If the fan has play (wobble) in it it prolly needs replacing. I sure have replaced a bunch of the tensioner and idle bearings.. I'd sure be suspicious of them two. Water pumps usually drip out the drip hole when done. Alternators have small bearings too. Not lately but in the past they have been known to squeal.

Big JIm

 

[Yooper]

After talking to a guy at work on Friday that does a lot of vehicle restorations I went ahead and changed the belt. He said he was pretty convinced that the problems I was describing sounded like belt slippage. So I threw a new Gatorback belt on there and it's been running nice and quiet.

I guess we'll see if that was the actual problem or if it's just covering it up.

Yooper

 

[JoshMcMadMac]

After talking to a guy at work on Friday that does a lot of vehicle restorations I went ahead and changed the belt. He said he was pretty convinced that the problems I was describing sounded like belt slippage. So I threw a new Gatorback belt on there and it's been running nice and quiet.

I guess we'll see if that was the actual problem or if it's just covering it up.

Yooper

You do know that these things are notorious for that belt squeal, right?