my fan belt makes a ton of noise but only when damp or wet out. a noise like rubber squeaking against metal. would tightening the belt help. and if so how do i adjust it? thanks

 

The belt is not manually adjustable, its on a tensioner. Belt squeel is usually due to wear and hardening of the surfaces. The water pump on the CTD runs on the back side of the belt and can cause most of the squeel. New belt is really not a big ticket for what it does. I go with the Gatorback from Goodyear as it seems to get rid of the shutdown chirp as well.

 

Usually the noise is from a loose belt. You're tensioner spring is probably getting weak.

 

Another vote for the Gatorback. Totally got rid of any noises and chirp.

 

I second the tensioner. Been there on my 99 and my 96. When the belt started making noise on my 99 I tried new belts and belt dressing, then finally a new tensioner. The tensioner did the trick. On the 96, when it started making noise I did nothing with the belt, just replaced the tensioner, and again, shut it right up. The Gatorback might shut it up for now, but it is just masking the real problem.

Chris

 

Ditto on the belt

 

I agree. The tensioner is defilitely something to check out. I replaced my belt only because I had to take the old one off to tab my KDP. It was checked pretty bad, so I figured it would be a good time to replace it. Bonus was that it silenced the shut down chirp. Seems to have much more grip than the old one.

 

Mine was the bearings on the belt tensioner. I just regreased them and no more squeal. Only thing is i gotta do it routinely.

 

definitely could be the tensioner. had the same problem. replaced my belt and it went away for a while and then came back. swapped out the tensioner and it has been gone ever since. at work we are very picky about tensioners making even a slight growling noise. we change them out and throw them away. I save them. They are off of 8.3 cummins ISL's. if anybody wants one i could arrange something

 

The tensionor itself probably won't work on a 5.9 but the pulley might. I finally put a new pulley off of a belt tensionr for a Cat C-9 that fell off a truck, on mine. works ok so far and no more squeal.