Check the routing of the belt, it is possible to put this belt on a different way. The right way requires you to fish the belt around the fan.

I was chasing a belt slipping issue for awhile. The belt was put on wrong by the previous owner and I put a new belt on along with a new tensioner hoping that'd fix the issue without verifying the correct belt routing. The old owner left a can of belt dressing in the truck ... I wonder why, haha. The only time it slipped though was when my fan clutch was cold or I imagine if it was hot enough for it to lock. It hasn't been hot enough here since I bought the truck for the fan clutch to lock.

Hope this helps someone! Also, should mention that I have a 1995 with a 3.9L and AC.

 

I discovered some time ago that cleaning out the grooves. a PIA job, on the rollers the serpentine belt rides over also helps get rid of the squeal.I used a brush, carb or tb cleaner and sand paper, then wipe down well with good clean rag.. It took a lot of tedious effort. There was a lot of old belt crap in those grooves.

 

The first vehicle I ever worked on that had a serpentine belt would squeal the belt under heavy electrical load. I had gone over rather than under a pulley and when the alternator needed to produce more power, the belt wasn't tight enough. On the other hand, single belts are better than multiple ones, especially when the belt that broke is in back of two or three other ones.

 

And wasn't it always the one closest to the motor that broke? Hey, I know, lets put the most important belts (the ones most likely to fail...) behind four others, just to keep the mechanics life interesting!

 

Those were the days.

 

At the shop I ran, I got a car with two a/c belts and a couple of other belts behind those. A customer came in with one a/c belt broken and wanted it fixed. I gave him a price for all four belts. Nope, replace the two a/c belts. Okay. Guess who came in a week later with a bad alternator belt? The belts were cheap, labor was the big cost.

 

It's like getting old and having to bend over to pick up something you dropped on the floor. You gotta ask yourself, "What else can I do while I'm here"?

 

Oh God. I am WAY to familiar with that sentiment.

 

I have one of those telescoping magnetic pick up tools just so i don't have to bend down to get it.