Can't find the "chirp" in my 7.3...

[chillman88]

And the alternator bearings are a bit rough (rebuild kit with bearings, slip rings, brushes and regulator on order) but when I pull its pulley forwards and rotate it back and forth, there is a squeak coming from there too.

My thought is I'd start there before tossing any more money at it. If you KNOW you have an unhappy bearing, there's a good chance that's what you're looking for.

I also noticed that the PS pump has about 1/8" of axial endplay (the pulley can be easily moved front and rear). Is this normal when it's not running?

I can't say if it's normal, but I've noticed the same thing with mine. Of course, who knows how many miles are on mine...

 

[DrCharles]

Well, I'm not just tossing money at the Pig in a Poke...

Everything replaced needed replacement anyway (tensioner pulley had rumbly bearing, idler pulley was getting there, water pump had lots of play at the fan tips, a/c compressor had black death, and vacuum pump had been leaking oil).

The alternator rebuild kit was only $26.94 shipped... and another trip to Autozone for the pulley puller I may actually buy the puller/installer set, it's $29 from various sources on Amazon.

 

[Thewespaul]

You can turn the alt over with an impact on a low setting and see if you can hear the same noise

 

[chillman88]

Well, I'm not just tossing money at the Pig in a Poke...

Oh I understand. Although at the age of our trucks... Everything is due to be changed out anyway lol! They're all money pits, but we love them anyway!

 

[hoodshauler]

Aha! that's the secret... I was clicking on the "Image" button in the posting toolbar.

A new and useful data point: I took the belt off and all is quiet! So it's not in the IP or some other "zebra", which is a relief. (Old medical saying: when you hear hoofbeats, think first of horses, not zebras).

I also noticed that the PS pump has about 1/8" of axial endplay (the pulley can be easily moved front and rear). Is this normal when it's not running?

And the alternator bearings are a bit rough (rebuild kit with bearings, slip rings, brushes and regulator on order) but when I pull its pulley forwards and rotate it back and forth, there is a squeak coming from there too.

Notice the far-forward position of the belt on the idler pulley after the engine stopped, too.

You must be registered for see images attach

You must be registered for see images attach

Thoughts?

You must be registered for see images attach

Glad to hear that pulling the belt off narrowed it down for you. Also that shock absorber tensioner is what was used on ambulances in the day.


Sent from my iPhone using Tapatalk

 

[DrCharles]

I did some Googling and it seems as though the PS pump endplay is normal.

Although I still plan to rebuild the alternator, the noise is definitely not coming from the right front.

After thinking about it last night, I think that the chirp rate is once per BELT revolution. It's 110 inches long, the crank pulley is about 18" in circumference (pi * diameter) so at 600 rpm (10 rps) the entire belt makes one pass over any given point every 110/180 = 0.6 seconds. Which is about the rate I hear... The fact that the chirping intensifies when the engine decelerates rapidly also points to a belt issue. But it really does sound like a metallic ringing, not a rubber squeal. And I don't see any unusual patch on the belt itself.

This morning since the belt is still off, I'll try and compress/extend the shock and see if it has any damping capability left. Then put it back on and see if anything's "flopping" especially during decel.

 

[SirRea63l]

I chased a squeak for a while, replaced belt, pullies and tensioners and it ended up being the water pump. I am glad I replaced the tensioner, it was not in good shape. I never mind replacing parts that are sure to need it in the near future.

 

[DrCharles]

Me either... but what worries me is that with the quality of replacement parts declining, what if the new part is squeaking too?

 

[SirRea63l]

I have not had that problem, yet. I went with the FlowKooler water pump and always try go OEM with other parts, if I can.

 

[DrCharles]

Found it... looks like Thewespaul was right!

I have located the chirp - it is definitely the tensioner itself. With the belt off, and a breaker bar/15mm socket on the bolt, rotating the mechanism against spring tension exactly reproduces the metallic chirp. Doesn't do it at all initial angles of the bar, either.

So, would I be wasting my time to remove it and clean/lubricate as necessary? Or just replace it. The shock seems to be damping properly (in proportion to its size).

 

[Thewespaul]

I would just replace it

 

[Fixnstuff]

As for uploading photos you may have to disable any ad-blocking software that you are running in your browser for the upload feature to work. Clicking on the 'image' icon above the text window you are writing in should then work.

 

[DrCharles]

I think I will too. Doesn't look like any easy way to lubricate it anyway, and it's enough fun to take it off once.

My local O'Reilly actually stocks them... for $85.99 (Gates 38270) plus tax. Ouch. The same part is only $59.99 shipped from Rock Auto but then I have to wait a week.

One important question - nobody has the tensioner with the shock absorber... the one listed above is for enclosed spring but no shock. Can I just use that one, and do away with the shock entirely?

 

[icanfixall]

Check ebay under title 1992 or 1993 ford diesel bhttps://www.ebay.com/itm/Ford-7-3L-Turbo-Diesel-Belt-Tensioner-F4TZ6B209C-Motorcraft-BT33-OEM-TAKEOFF/222084181385?fits=Year%3A1992%7CMake%3AFord&epid=76818658&hash=item33b53fad89:g:Wt8AAOSwbwlXDUKNelt tensioner.

 

[hoodshauler]

You can use the one without the shock


Sent from my iPhone using Tapatalk