Belt Tensioner Noise

Dont venture in here much, but my dad has a 2008 DCSB with the big 4.0 in it, approx 115k on the clock. Anyways, for the past couple of months we've been hearing a rythmic chirping noise coming from the front of the engine. He's had 2 idler pulleys replaced by Toyota in the past so that rules out those. Took it to Toyota today for them to look at the noise its making now. Their prognosis was "best we can tell, the belt tensioner assembly needs to be replaced. $850" He elected to think on it some.

Now, I dont know a whole lot about engines but I have had some experience with pulleys and bearings at my job. As I understand the tensioner assembly has a pulley with a bearing pressed in it attatched to the tensioner lever. Now, if the tensioner assembly was bad, wouldn't it loose belt tension? Bearings are what usually make noise. Is it possible to just replace the pulley and bearing? Any advice is much appreciated.

 

I found an excellent post by @Chuy on this. Gonna stop by my local industrial supply and see if they have a Nachi 5203-2NS bearing. Will also replace the serpentine belt. Fingers crossed.

 

With the belt off, check all the other bearings - alternator, PS, AC, and the idler pulleys. When I replaced mine, the pulley next to the AC had the most play, but the tensioner was pretty loose also. I've only seen Nachi bearings on Amazon. "5203" should be a universal bearing #, but the suffix digits change with brands. Take the dimensions to be sure you get the right one, or the old bearing if you remove it first. Good luck.

 

Ive worked as an apprentice in industrial maintenance for the last year. We have a large industrial supply in town where I can get Nachi, SKF, FAG bearings there. The 3 other idlers were already replaced last year so no problem there.