Idler pulley for the AC Belt

[r1burden]

I have only had my 95 4runner
for about 2 months. I have ran into a problem where the Idler pulley bolt for the A/C Belt is backing out and losing up the belt, so I get a lot of squealing and no air. I tighten the bolt back up and all is fine. This has happened twice so far

my question is should there be a nut on the other side of the bolt to act as a lock or should it just be the bolt going through the back of the idler pulley bracket

does this make since?

 

[Telepresence]

do you have the 22RE or 3VZE?

 

[Telepresence]

here are some photos of the AC tensioner on my 95' 3VZE.
there is a bolt behind it that allows you to loosen/tighten the pulley.

Front view:

Side view (passenger side, camera facing driver side):

Bottom view (camera facing up):

I can take a peek at my shop manual if those pictures dont help.

 

[flyinhawaiian01]

The greasy bolt is what holds tension on the belt, the front bolt also needs to be tightened down once you have the correct tension on the belt.

To correctly set the tension, you loosen the front bolt going through the pulley,not a lot, just enough so you can take the slack up with the bolt in the rear(your greasy bolt in your last photo), once you have set the proper deflection on the belt, you then tighten the front bolt back down to keep it from moving around.

If the belt is cracked or frayed, you won't be able to get the proper tension on it, as it will stretch pretty quick and you'll end up with a squealing belt again. Replace the belt if it doesn't look good. Also, if you hear the bearing making a whirring or squeaking sound, press it out with a vice and replace it, most parts stores will have that bearing in stock. Have them look up the bearing part number, not the toyota pulley part number. They're relatively cheap IIRC, and are pretty easy to press out with just a shop vice and a proper-sized socket.