Idler pulley or a/c problem (halp!)

•2007 4.0 DCSB 4x4 71,491 miles
•Original pulleys and serpentine belt
For the last couple of years when the a/c compressor kicks on I've been hearing a rattle/grinding type of noise. Yesterday I popped the hood with the a/c running and noticed the serpentine belt vibrating and visibly wobbling between the compressor and alternator only when the compressor was engaged. So... Today I took off the serpentine belt and felt of all of the pulleys, water pump, compressor pulley bearing, power steering pump, and alternator all spin freely and appear to have good bearings. I also spun the compressor itself by hand and it felt fine to me, I'm no a/c expert though. Next I felt of all of the idler and tensioner pulleys, the bottom pulley and tensioner pulley feel good spinning and have a little resistance as you would expect them to, I can wiggle them side to side and they have a little play in them, enough to hear a slight click as you rock them. I then felt of the top two pulleys and they both spin as you would expect them to, but they have a slight bit more wiggle to them side to side than the bottom or tensioner pulley, so I removed them and they will rattle slightly when you shake them.

So my question to all of you is this, if you shake a new pulley/bearing does it have any rattle to it at all? The pulley nearest to the alternator has more rattle that the other side does, so I'm hopeful that's where my issue lies. I first thought that it may be the compressor or compressor clutch going out, so my plan was to drive it till it quit, then replace the whole a/c system...but like I said it's been a couple years and the a/c is still as cold as it was when it was new, I'd think it would have locked up by now if it was going to. It's to a point where you can feel the vibrating through the pedals and steering wheel when accelerating or decelerating and actually hear the grinding/rattle noise when the a/c is on with the radio off.

I haven't entirely ruled out a failing compressor yet, but I thought I'd take a look at it and be sure what I have going on before I take it in and let some moron fix a problem that doesn't exist(if you know what I mean).

So, what's my course of action, TW?

Edit: I put halp in the title for my own amusement... Brb, I'm pouring ATF in my coolant reservoir

 

No. A bearing should have zero clearance to wobble or shift side to side. Any roughness will be magnified when that pulley is put under a load such as when the compressor kicks on and now the belt has to be pulled around the compressor pulley which is not an easy task. The clicking usually tracks back to the tensioner since it has to keep everything tight. But all of the idlers are about an equal probability of failing. If the pulley has a wobble, either replace the bearing or replace the entire pulley.

 

Do you know if the Toyota bearings are sealed now or not? I was doing some reading over on the fj forums and someone claimed that the bearing are different and now require a different washer/dust cover.
From what I've seen, most people go with the gates kit, I can get it from rockauto for $170, including the tensioner. Or should I press out the old bearings and install new ones, if I can find the bearings?

 

"sealed" is a vague term. There is no way to actually seal the bearing since the two pieces have to rotate independently of each other. However most every bearing I have seen on those kinds of applications are "sealed" since in a heavy rain, water is getting in past the radiator anyway, and washing the grease out will strand you on the side of the road. No idea about any change they have made, but I have replaced a number of these over the years, toyota and others, and the only difference I see between buying the bearing itself, which is easy to match at a good parts store, and the complete assembly, is the effort involved (and the expense of course). If you can press it out yourself, it is easy enough. If not, sometimes locating someone to press it out can be problematic.

 

Are all Tacomoa tensioner bearings 17mmID&33mmOD

 

If the noise is only there with the AC on the problem is not the bearings it's the compressor. All of the same bearing are turning AC on or off. Yes the bearings are sealed no one makes bearings you can grease any more if grease can get out water can get in.