Most likely someone didn't put the belt on the water pump pulley right, and it tore that rib off. Move the belt one rib forward on the water pump and see if it stays or if it jumps back to where it is. If it jumps back pull the belt off and see if the pump shaft has any play, your pump may be going bad.

You can't shim or move the pulley back.

Dave

 

In this pic, this looks to be the problem. It is hard to tell if the belt is either too wide or if it is off by like 1 rib. That is what it look like to me.

 

Looks to me like its off one grovve on the crank pulley too.
Buy a new belt and get it on there right and it should be fine.

 

It can't be the alignment of the belt on the water pump pulley, groove-wise. As you can see, the water pump runs on the outside (smooth side) of the belt; it's not a grooved pulley. But unlike the other smooth-side pulleys, there are front and rear "limit" edges on it, that the belt rides in between. It's the rear limit that the rear edge of the belt is contacting, and there's quite a gap between the front edge of the belt and the front limit on the pulley.

I'll have to look at the way it runs on the crank pulley again. In the photo, the front of the truck is at the bottom of the picture. Like the other grooved pulleys (A/C, P/S, etc.), from what I can tell, the front edge of the belt rides on the front groove, and there's a gap between the rear (frayed) edge of the belt and the rear edge of the pulley. I don't think it can be moved forward one rib.

Though it is possible that the belt is (well, was) one rib too wide. Certainly a belt one rib narrower would fit all the pulleys. Fah, the NAPA number was right on top when she parked it last night, and I FORGOT to take it down.

 

I think the early trucks had 7 rib belts if my memory is correct.

Tom

 

That's what I got to thinking awhile after my first reply. I know someone like Dieselfever could tell us for sure.

Dave

 

You've got a late 95 with the 8 rib set up. 94.5 and early 95 had the imfamous 7 rib set up.

It doesn't look like its rubbing (all ribs appear very intact) but have you verified there nothing in the belt path (bracket, etc) that is rubbing on the belt? How old is the belt in the pic?

The pics don't show a lot of belt detail, it also looks like the tensile cord showing a little edge cord pullout. It takes a fair amount of misalignment, but it happens when the cords on inside are tensioned more than the outside. How is the alignment of the tensioner? The factory tensioners will tear themselves up from the inside and the arm can become very misaligned in the cup. Easy to check is to put a bar on the arm and wiggle it fore/aft while you have tension on it to open it up.

If you have any better pics of the inside of the belt, that would be helpful.

 

You've got a late 95 with the 8 rib set up. 94.5 and early 95 had the imfamous 7 rib set up.

I've got an 8/94 PSD in the shop right now with 8 rib pulleys. It's also got an automatic, which I didn't think was offered until late 95?

Dave

 

Dunno how old the belt is; we just took possession of the vehicle. I _think_ it's in the service records somewhere. Can't be that old; the NAPA logo and belt number, etc. are still prominent on the outside of the belt. Tensioner was replaced recently, but thanks for the advice, I'll be doing that alignment check at next opportunity.

It's the aft edge of the belt that's fraying. I had the same idea, and checked the whole path for a protruding bracket, misrouted wire, etc., and couldn't find anything. I'll get out there and get more pics of the rib-side of the belt in the next day or two. Thanks again for the info and advice.

I believe the truck was built in March of '95. Does that constitute "late"?

 

Sure, no problem. Finding these types of things, especially a pulley alignment issue, can be difficult. I wasn't sure on the belt as the one rib pic looked pretty good (no rib cracking) and I thought the belt may be fairly new. What I couldn't see was large amounts of wear on the side of the belt all the way around; is wear located in one area?

What you should look for is if it gets worse. The installer may have tried to force/pry the belt on causing some damage (broken edge tensile, cover damage,etc). Installing another belt without prying could fix it.

The production year often changes in the fall of the proceeding year. Some very early 95 year trucks got the 7 rib drive. Ford likely scheduled a midyear change, which consisted of minor drive geometry changes (brackets, etc) and went to the more commonly available 8 rib belt.

(BTW; I sell belts for Gates Corp to the heavy truck OE market. Happy to help with other issues if needed...)

Mike