F-Super Duty Chewing Belts

[ISPKI]

My 1994 F-Super Duty seems to want to shred one rib off it's serpentine belt. Just installed a new belt about 100 miles ago and suddenly a rib sheared off. Upon closer inspection, the top right idler pulley is set 1/4" rearwards, towards the engine block when measured against the other pulleys with a straight edge. I loosened the bracket to try and see if it had some adjustment but it did not. I cant find this part on Rockauto, anyone know where I can get a new one or how I can fix this one?

 

[chillman88]

Upon closer inspection, the top right idler pulley is set 1/4" rearwards, towards the engine block when measured against the other pulleys with a straight edge.

That's an impressive amount to be off! I'm thinking there might be a spacer missing behind the pulley? Is there room to put a couple flat washers behind it? I've never worked on the serpentine setup on these, both of mine are V belt.

 

[ISPKI]

That's an impressive amount to be off! I'm thinking there might be a spacer missing behind the pulley? Is there room to put a couple flat washers behind it? I've never worked on the serpentine setup on these, both of mine are V belt.

I dont think so, the shoulder is just shy of the end of the bearing and I am concerned that if I space it out, the bearing will wobble and break something. Also - I cant find a washer that fits it. Will likely have to machine something custom.

 

[Randy Bush]

Is this something all the sudden or was the truck worked on?

 

[IDIBRONCO]

That's strange. From what I know, it's usually a worn tensioner that causes the belt to be chewed up.

 

[chris142]

Shim it out with washers?

 

[ISPKI]

Is this something all the sudden or was the truck worked on?

I just bought the truck a few months ago and it had 1 rib missing when I bought it. I figured maybe the previous owner didnt install the belt correctly or something so I went ahead and put a new gates belt on it. Ran fine for a few weeks and then it sheared a rib off in the parking lot at work. Now, it still runs fine and it doesnt seem to want to shear off another rib but it doesnt sit well with me to have it doing that.

Problem I have now is, I cant find this pulley anywhere. Looked it up on rockauto but im not seeing it anywhere. It goes in place of where the A/C compressor would normally mount.

Another item I was thinking about; Didnt these F-Super duty trucks come with an optional engine mounted air compressor, or alternator, or something mounted in the top right location? It looks like the mounting pattern is similar to the other alternator's mounting position. I wonder if it is as easy as just buying another alternator and bolting it on.

 

[Randy Bush]

Can you post a picture of the situation, pulley on the truck.

 

[ifrythings]

I would pull the belt off and check the vacuum pump pulley to see if it’s worn out and causing the belt to track funny, I would also see if the power steering pulley is pressed all the way on.

Here’s a picture of my setup for reference, it’s missing the vacuum pump.

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[ISPKI]

Ah, thanks for the picture, I havent been able to take one yet.

So, I dont think any of the other pulleys are the issue. I did put a straight edge on the vacuum pump pulley, water pump, and power steering pump and they all line up nicely with each other but the idler in the top right is the only one I found that doesnt line up. it is set back almost 1/4".

 

[chillman88]

This should be what you need according to their listing. Assuming it's actually correct...

https://www.1aauto.com/ford-mazda-l...S189Mu7-TpO4WRwZYfPvs4ziMfEybU1RoCsV0QAvD_BwE

 

[jwalterus]

This should be what you need according to their listing. Assuming it's actually correct...

https://www.1aauto.com/ford-mazda-l...S189Mu7-TpO4WRwZYfPvs4ziMfEybU1RoCsV0QAvD_BwE

A junkyard a/c compressor that spins freely would be cheaper around my parts.

 

[Double-S-Diesel]

not sure if it the same on and idi but the early 94 psd had a 7 rib belt verses the later 8 rib.
Ive seen on the psds alot of stuff replaced with 8 rib parts.

 

[TNBrett]

Looks like the picture of the new part (dorman 34180?)shows a spacer that might go between the pulley and the bracket based on the application . Perhaps the PO installed it, but tossed the spacer in the “F***” it bucket.


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[WarNose]

I had a belt problem on a 94 with the 4.9 6 cylinder that I couldn't figure out. All of the pulleys looked fine, lined up, with no wobble. One day I decided to change the water pump just because I knew it had a lot of miles on it. I never had a belt problem after that. The old pump must have been making some vibration that I couldn't see at idle speed while I was looking it over. It also had the idler pulley that replaces the AC pump. I don't think the aftermarket makes a new one. But they might just make the pulley wheel itself with a new bearing. Like another said, a junkyard compressor might be another option.