My truck has had a noisy belt for the last couple of years. I'd describe it as a chirp or squeal that gets louder with increased RPMs. A couple of months ago I couldn't take it anymore (the neighbors were probably sick of it too) so I decided to try to finally identify and fix the problem. The stealership wanted $400 to replace the tensioner and belt. I said no thanks.

I bought the truck from a diesel repair shop with about 200,000 miles on it. They had "rebuilt" the engine, but I figured hadn't replaced many parts. So I started by replacing the tensioner and belt. The noise went away for a couple of days but then slowly came back as loud as ever. So I replaced the idler pulley; same thing happened. Next I took the belt off and checked all the pulleys. They turned freely, didn't make any noise and didn't have any play (the power steering pulley moves about 1/18 inch in and out, but that seems normal from what I've read online). The belt looked to be riding in the pulley grooves okay.

I figured the problem had to be slippage caused by glazing on the belt and/or pulleys. I've read recommendations to deglaze the pulleys with emory cloth/scotchbrite or a wire brush. That didn't sound like a very fun morning. Then I read online about a trick to put Ajax or Comet on the belt to deglaze. So I poured some Ajax on the belt with the engine off, started it up, no noise. I repeated once more.

I've been driving for 3 days now and the noise hasn't come back. Eventually I plan to switch to a Goodyear Gatorback belt, but right now I don't want to put any more money into the truck, especially since the belt is already new. I hope this "fix" keeps working. I'll report back if the squeal returns.

Hope this helps someone in the future. Any comments on whether I've caused some damage?

Brian

 

I think that's a great idea and I am going to try that on my squeaky belt, too.

 

Interesting idea.
I am trouble shooting a belt squeak on my wife's truck as well. I replaced the 3 bearings in the tensioner and idler pulleys and that didn't help (although one of the bearings was hurting...). The squeak appears when first started, the colder it is outside, the louder the squeak. After driving for a little bit the squeak goes away. Very annoying. I just might try your idea. Thanks.

FYI....I tried the Gatorback belt once. It only lasted 50k miles. The OEM belt seem much better IMO...

 

The abrasive nature of the Ajax makes sense. I've had a similar repeat problem when I managed to get power steering fluid or a good bath of coolant on the belt in other vehicles, and the only way I got rid of the problem was with a narrow-tipped screw driver, a rag, and a strong solvent.

What I would be concerned about with the Ajax, though, is the fact that it might chemically attack your belt over time, especially since it will run at elevated temperatures. Ajax, Comet, and the likes are all caustic chemicals, and the EPDM which our serp belts are made from typically have a "good" resistance to caustic chemicals, you have to remember that you've potentially embedded abrasives into the belt surface as well, and the combination might somewhat reduce the life of your belt.

I, too, have been less than pelased with the Gatorback belts, and will only run a Gates (unless I'm stranded and have no other option).

 

I got a gates fleetruner 2 years ago and have hade no problems at all it is spendy but worth it to me

 

Good to read the reviews of Gatorback. They're difficult to find in auto parts stores around here (SoCal). Now I'm inclined not to bother getting one. The belt I currently run is the "premium" brand available at Autozone, Dayco I think.

I hope the abrasive cleanser doesn't ruin the belt, but I'll keep a close eye on it.

The other possible cause I've read about on this forum is lettering on the belt causing slippage on the smooth pulleys, like the idler. I haven't pulled my belt off yet to look for printing, but maybe I'll do that this afternoon. I guess I'll sand it off with 220 grit sandpaper if I find any.

 

Sounds like a good idea. Only time mine squeaks is when its wet from off roading.

 

Yeah, but every belt made today has printing on it? I haven't read the other posts though.
I replaced mine yesterday, same issue. I did clean the pulleys, they all had little bits of rubber on them. I put a Dayco on it, thinking it was an improvemnt, only to find that is what previous owner did. Had maybe 11k miles, started making noise this last couple of months.
So far so good, guess next will be a Gates or OEM. Sure am glad I replaced the upper hose with the wrap around one!! Much easier.
Tom.
01 F250 CC 4x4 7.3 204k.

 

I would think that a new belt and tensioner would be quiet.... for a long time.
What about cleaning the pulleys ?
If it squeaks after that couldn't it be something else causing the belt to glaze and make noise?

 

Mine has been squeaking for about 2 weeks now, yesterday I sprayed some engine degreaser on the belt and that worked well. I use that stuff on my ATV's. But if it starts squeaking again I might try some comet! Thanks!

 

Anyone with a belt squeak needs to get a GATES green stripe. They are made with real rubber. The squeaking and squaking most folks get comes from the crappy poly belts slipping on the water pump pulley. I spent lots of time and money trying to get mine to stop. I replaced all ideler pulleys, tensioner, sanded all pulleys, etc. Tried two different brands, dayco and napa, both squealed badly. Buddy of mine had same problem with his PSD and said he put Gates on his and squeak went away. I did the same problem solved.

 

Mine started to squeak again, the engine degreaser that I used did not last too long. I used some comet and it has been squeak free for 5 days now, great idea bkgeig! Thanks!

 

Greg, did you replace JUST the bearings, i.e. disassemble the tenioner and press out/in new bearings, or did you use new pulleys?

Pop

 

I just replaced the bearings and re-used the pulleys (two smooth and one grooved). The squeak goes away once the engine warms up and can not be heard for the remainder of the day. Then the next morning....'chirp, chirp, chirp' all over again (until it warms up).

Before I pressed out the old bearings I gave the pulleys a spin and the smooth one on the tensioner was grumbling so I figured I found the problem. I put it all back together and the squeak was gone, but it was warm afternoon weather out...
Sure was a let down when I started it up the next morning in 40 degree weather and the noise was back. Oh well, gives me an excuse to turn the radio up a little bit.

 

Did you use a bearing retaining compound (such as Loctite 609, 620, or 680)?

Pop