1991 F250 4WD, 5.8 w/162k
Hi- I've gleaned a lot from the forum but this is my first post. Searching the forum didn't turn up anything that helped.

I've had this truck for a year and had several problems with the serpentine system. Water pump went first, replaced and all was good for a short time. Then the alternator bearing started going. Long story there, but ended up with a new altnernator. Shortly after installing the new alternator chirping, then squealing started. Water test decreased the chirping/squealing but it did not go away. I pulled the smog pump, cleaned and repacked the bearing. After installation it sounded much improved for a week, then chirping resumed followed by a belt being earn.

I checked alignment of the pulleys with a straight edge and found the smog pump pulley has an angular alignment issue...possibly parallel too but wouldn't be able to tell unless it first came into alignment. It seems to be out between 1/16 - 1/8" , tilted towards the crankshaft. There are two bolts that hold the smog pump and seem to be the only way to potentially adjust alignment. Conceptually, the upper seems to be the one which needs to be adjusted inward. I'm not certain if that is possible?

Any advice about aligning this pulley would be appreciated.

 

Might also check the the pulley itself is installed correctly on the pump. And a picture would be helpful. I know on my 91 F250, 302, there is no adjustment that I can see. Pulley bolts to the pump, pump to bracket, bracket to block. Only thing I can think of is the pulley is not on correctly, or brackets not mounted correctly to block. Also, if pump/pulley was ever removed, make sure pulley is on correctly. There is a front and a back side. And spacing is different for both sides.

 

Thanks much for the response and suggestions. I checked the pulley and it appears to be oriented properly. I tried removing the bottom "z" bracket and shimming both bolts with a thick washer, but it did not noticeably change the alignment. I did a little more investigation with the straight edge and took some photos (see below). I'm at a bit of a loss right now, thinking about either getting some professional help or pulling the alternator to get a better look at the mounting bracket. I suppose a third option is taking on the smog pump delete, but I'm less inclined to go that route.

Smog pump pulley from below with straight edge across driveshaft. Note slight (less than 1/16") angular misalignment.

Smog pump pulley to alternator pulley. Appears as parallel misalignment of close to 1/8". Further examination showed the alternator pulley to be aligned with the driveshaft, tensioner, and power steering.

Crankshaft pulley to alternator pulley. Not the best photo but shows well enough they are aligned.

 

Any chance that pulley was just put on backwards by someone before you? Or they just put the wrong pulley on altogether? Unbolt it and flip it over, see if it lines up better. If not, I'd grab one out of a junkyard.

 

I would go with what Scott Bowmaster said, everything seems correct. And it is only the smog pump pulley that is out of alignment. Is it possible to put some small shims behind where the smog pump bracket mounts to the block? From what I can tell, everything except the smog pump is correct. Weird little issue here. Keep us posted.

 

Remember to verify the tensioner moves freely! Also noticed the plastic tensioner pulley. They do dry up over time. If theres any notchy spots get a new one. Rock auto sells them resonably

 

Thanks! I live on an island and don't have easy access to a yard for used parts. Probably cheaper and easier to order a pulley. The pulley is stamped with "front" on it so I assume I'm mounting it the right way. Definitely worth trying a flip, but I think the problem is not a parallel alignment but angular. If I'm not mistaken, the bracket is for both alternator and smog pump so probably can't shim between the bracket and block without affecting the alternator alignment. A buddy looked at it with me last night and we didn't figure anything out other than removing both alternator and smog pump to see if something might be going on with the bracket.

The tensioner is new, but has a few scratches on the pulley from the belt shredding incidents. I thought I'd ordered a tensioner with a metal pulley rather than plastic, but didn't arrive looking like the photo and I just decided to suck it up and install.

 

Update: I'm not certain that I've actually resolved things but things seem to be working better. While going through the serpentine system piece by piece again I noticed the power steering pump pulley had a little extra play. I replaced the power steering pump, finding it had been leaking a little in the process. Despite there still being an apparent pulley misalignment everything seems to be working okay - no noise from the belts, belt tracking looks good, and I haven't noticed any belt wear so far.

 

Good to hear!
I'm still a little baffled by that alignment issue you have. But hopefully with the PS pump/pulley working correctly you won't have any more issues.