Hi guys.. am pretty new to these forums, but I must say its very informative, and there seems to be a wealth of experience here.
I have a '94 softop sidekick.

Lastnight, my alternator belting broke.. 2nd time in 6 months! Had a look at the power steering belting, and that was looking worn too (last changed about 10 months ago... so what gives?
I changed both belts, cleaned the pulleys as they had some corrosion on it.. anything else you guys think I should do?

For info: the pulleys appear to be aligned, although the aircon compressor pulley and the fan are wobbling a bit, but not quite sure if enough to give me my problems.

Any input would be great. thanks in advance.

even slight wobbling will throw the belt sometimes. I know when I made my lower alternator bracket to put on the gm alternator I had to be within 1/8 of perfection or it would throw the belt. Also if there was excessive corrosion that may be doing it.

Not sure if yours is setup like mine is, but if the A/C and Power steering use the same belt then it is.  (alternator and water pump/fan use the other belt on mine).  

Anyway, if the compressor pulley is wobbling, check and see if it's the pulley itself or the entire compressor.  I found that on mine the lower bracket that the compressor mounts onto had a problem.  The bolt hole on the front side of the bracket had become elongated from wear against the bolt.  The bracket is just mild steel vs higher grade steel in bolts.  (Bolt 1, Bracket 0).  When this happened to me, the vibration from the misalignment caused metal fatigue in the A/C refrigerant lines where they connect to the compressor and as a result one of the hoses broke open, and vented the refrigerant.  (Thought I had an engine fire as it looked smoky, thankfully it was just the line).  

To fix this and prevent it from ever happening again, I sourced some Drill Jig bushings, drilled out the bracket and pressed them in.  Had to play around with the bolts a little and switched them out for some grade 8 3/8" ones with locknuts.  I'd had previous problems with them losening up on me etc and got to the point of hating to have to mess with them regularly.  I also drilled the mounting lugs on the  compressor itself and put some bronze bushings in there with epoxy since they'll take the rubbing a little bit better than the aluminum casting will.  It's now rock solid.  Also the way I set it up, it pivots freely at the bottom rather than being tightened in place there too.  Makes taking it out a whole lot less trouble.  

Another easy mod (if you have a welder) is ditching the bracket that keeps tension on the belt.  First you need to put a stud in the compressor where the bolt that holds tension goes. (8x1.25x40mm on mine).  Threading the old bolt to keep tension for the belt system puts a whole lot of stress on the casting that frankly doesn't need to be there.   To make adjusting it easier though, I sourced a couple of 5/16" spherical rod end bearings. (male variety, 1 regular, one left hand thread.  Get the jam nuts that go on them too).  This allowed me to make a turnbuckle style setup that's infinitely adjustable, but locks it in place securely and is easy to adjust.    To built it, I also got a pair of nuts for the spherical rod ends in addition to the jam nuts, again one regular, one left hand thread.  I took them to the metal supply place and found some stainless tubing that just barely slipped over the outside of the nuts.  (believe it was .625 ID).  You could use mild tubing but I figured the stainless would look nicer without paint or powder coating it, it's probably a tad stronger too.  

Anyway you only need about 2 inches of the tubing to do this.  I think the center to center on the link ended up being 3 1/4" and I had to cut about 1/4" off the threaded ends of the spherical rod ends to get it short enough. to fit the span correctly.  The tubing ended up being a whopping 1 5/8" long in fact.    At this point just weld the nuts into the ends of the tubing.  Clean it up a little bit, screw in the rod ends and you're done with the link.  

You need to remove the old bracket and chop most of it off.  Just leave enough to put either an 8x1.25mm bolt or 5/16 bolt through to attach the engine side of the adjustable link.  You might need to use a socket head bolt to get it to fit as the threads need to point forward to get the link to align properly.  Alternately you could weld the bolt to the back side of the bracket or even thread the bracket and put in a stud.  I took the lazy and easiest route of using just a socket head bolt and a lock nut.  Put a locknut on the compressor stud as well.  You may need to stack a few washers behind the rod end bearing on the compressor end to get it to line up better.

**continued in next post, sorry it's so long**

Anyway to tension your belt you just swing the compressor to where it'll fit the rod end link.  After that twist the link's middle section until you acheive the desired tension on the belt.  I was able to do it just by hand, if you want to be able to put a little more torque on the link, drill a hole through it that you can fit an allen wrench through to give you better leverage.  After you've got it set right, just tighten down the jamnuts against the ones welded into the tube and your'e done.

This will definitely make adjusting the tension on that belt a whole lot easier for you.  It looks much cooler too, and the beauty of the setup is that it won't possibly loosen and make you lose belt tension.  You can also adjust things much more precisely since you don't have to worry about using a prybar or whatever on the compressor while you're tightening down the bolt like on the factory setup.  

Total cost on this was about 12 bucks too.  (3.50 each for the rod ends, 4 bucks for the tubing (had to buy a 3 foot section).   The only difficult part is welding the nuts into the tube.  If you have a TIG Welder it should be easy, a MIG however makes it difficult as the wire feeding makes the nuts move as you try to weld em.

I'm planning on nixing my alternator bracket for one of these too at some point.  Lastly, don't worry about locating metric rod end bearings.  They exist but they're a real pain to find.   Probably will have to order from somewhere like maryland metric to get them.  Since this uses an 8x1.25mm stud/bolt, you can freely interchange 5/16" bore spherical bearings and it fits nicely, actually it's slightly more snug than a 5/16 bolt, but still loose enough that it won't sieze on you.  5/16 is 7.93mm, close enough for me, especially in this sort of application.

Oh and one more thing, might just be the bearings on the A/C compressor pulley are getting worn, check those if it's just the pulley wobbling not the whole compressor.

wow.. thanks for your reply mate.. but it is just the pulley.
Can that mean that all/most of my pulleys are worn? (since it was the belt connected to the alternator/ waterpump that snapped, and the one connected to the PS/compressor is worn) But I would have expected a longer life from these pulleys.
Jeez.. this problem is killing me.

You say the belt "snapped" where most belts
shred, starting from the side.

Is the belt you bought a good quality part?
is it a defective belt, look at the broken location,
is it at a factory made joint? wobbly pulleys and
a little rust just isn't that big of a problem.

I have 260,000 Miles on my SideKick, stock
pulleys on Crank and Water Pump, alternator
has been changed, so I don't think it is a milage
problem as in worn out.

Just some thoughts, hope it helps
Darrin