I have a bad idler pulley (the one underneath the tensioner and near the air box). I'd like to buy a bearing for it and press it back in, but have to take it off to do that. Anyone have the bearing number or dimensions of the bearing?

I'm actually guessing it's the same as the one I need for my fords, and can order all three at once.

I'll have to go look at the one on my Duramax to see if it's the same, but on my Yukon, the pulley is plastic and apparently is injection molded around the bearing during manufacture. There is a lip of plastic on either side of the bearing and if you try to press it out, it breaks the pulley. I know, I tried it....

Usually a new idler pulley with bearing doesnt cost much at all. I agree with the above poster, that most are plastic and cant be pressed out without breaking them. Hopefully you caught it before it froze and broke the belt. How many miles are on it? Guess i haven't heard of anyone having the idler pulley on the duramax's go bad yet...always a first.

50k miles. I found a loose bearing during a routine belt change.

I know they aren't expensive, but I have a mustang and a spare ford pulley that need the bearing. The pulley wasn't worn much, and I am already ordering the bearings and pressing them in and out - just thought I'd save some money.

I hate plastic pulleys. Wait till they get old and the belts won't track on them until they are trued on a lathe....

Well, I just ordered it. It's not my idea of cheap - $60....

I guess if I can change the bearing I'll have a spare pulley.

The duramax idlers are not plastic and also not cheap. Bought three last week and they were $60 each. None of my wholesale parts houses even listed it. It was a dealer item.

I just got off the phone witn GMC. It's actually the tensioner pulley I need - and they only sell it with the tensioner - $120 but he'll give me wholesale....

i can get the steal idler pulleys for 15 bucks from the dealer, just got 2 of them

I paid $17.24 apiece for the two idler pulleys on an '05, at a dealer that charges me full retail. And this was in January of this year. Gmpartsdirect has 'em at $10.22 apiece plus their shipping charges.

I just got off the phone witn GMC. It's actually the tensioner pulley I need - and they only sell it with the tensioner - $120 but he'll give me wholesale....
$113.07 list, but agaain, GMPartsdirect has it for $67.09+.

The tensioner pulley is only $18.99 at Advance Auto
Goodyear Drive Belt Idler Pulleyhttp://www.partsamerica.com/product_images/img/logos/goo.gif (http://shop.advanceautoparts.com/BrandCategories.aspx?MfrCode=GOO)http://shop.advanceautoparts.com/images/spaclear.gifPart Number: 49021http://shop.advanceautoparts.com/images/spaclear.gifhttp://www.partsamerica.com/product_images/img/goo/49021.jpg (http://javascript<b></b>:popImage('http://www.partsamerica.com/product_images/img/goo/49021.jpg', 'Goodyear 49021');)

sorry, off topic. who sells the goodyear gatorback belts?

Yesterday I bought 2 idlers for my Duramax at my local GMC/Buick/Pontiac dealership. They were $19.50 each plus tax. Both of mine were on the LB7 were tight and squeaky. One was nearly locked up.

I priced the bearing for the originals at the cost was $24.89 each. Then I have to spend the time to press them out, save the dust shield somehow, polish up the bushing and mic all those parts back in to get it like new.

Obviously its a money savings and time savings to just buy new ones. Even for a spare...its cheaper to buy a new one and keep it handy.

My tensioner pulley was still smooth but had some side play. The tensioner assy was still tight and and smooth in its swing arc. So I just polished off the dust and installed a new bearing into its pulley. I used a press to remove and a perfectly sized socket to install with a mallet. Using a press to install to bottom it out is risky to me. Could bend the pulley. It went together real easy. In this case the bearing was $8.46 and the new tensioner assy was $135. So here the savings is clear and the time was minimal. Good deal to do this one.

The bearings in both cases are NTN 6203LLC3EM for the tensioner pulley and NTN 6005LLC3EM for the idlers.

I also ordered a Gator Belt from Autozone. Know which amp alt you have (105 or 145) or duals, and if you have the EGR vacuum pump. There are four or more belt choices. I'll keep my old belt and the one idler that seemed still functional as an emergency backup. I'm going to soak the old idler in oil for a few days and try to force some oil onto the bearing just to see if it helps it.

Yesterday I bought 2 idlers for my Duramax at my local GMC/Buick/Pontiac dealership. They were $19.50 each plus tax. Both of mine were on the LB7 were tight and squeaky. One was nearly locked up.

I priced the bearing for the originals at the cost was $24.89 each. Then I have to spend the time to press them out, save the dust shield somehow, polish up the bushing and mic all those parts back in to get it like new.

Obviously its a money savings and time savings to just buy new ones. Even for a spare...its cheaper to buy a new one and keep it handy.

My tensioner pulley was still smooth but had some side play. The tensioner assy was still tight and and smooth in its swing arc. So I just polished off the dust and installed a new bearing into its pulley. I used a press to remove and a perfectly sized socket to install with a mallet. Using a press to install to bottom it out is risky to me. Could bend the pulley. It went together real easy. In this case the bearing was $8.46 and the new tensioner assy was $135. So here the savings is clear and the time was minimal. Good deal to do this one.

The bearings in both cases are NTN 6203LLC3EM for the tensioner pulley and NTN 6005LLC3EM for the idlers.

I also ordered a Gator Belt from Autozone. Know which amp alt you have (105 or 145) or duals, and if you have the EGR vacuum pump. There are four or more belt choices. I'll keep my old belt and the one idler that seemed still functional as an emergency backup. I'm going to soak the old idler in oil for a few days and try to force some oil onto the bearing just to see if it helps it.


The originals are 6203 bearings like you said, but they are an automotive spec. I think GM just did this to keep people like us from saving a hundred dollars on bearings. I have a hard time believing that they require any funny clearances or other modifications. Price is about $6 at motion industries.

I wouldn't risk a $50 belt that takes an hour to put on for a $6 bearing that seems dry.

sometimes the spring in the belt tentioner get weak. it starts to let the belt jump around. seems like the higher the rpm, the more it shows