Drive belt idler repair

[Philip]

I have seen a few people post in other threads wondering about being able to repair the idler assy if the bearings start making noise. I replaced mine a couple of days ago. So I decided to use the old one as a sacrifice and see if it was possible.



Well I am sorry to say that it is not possible if you have an idler with the plastic roller assy. The roller assy is injection molded as one piece with the bearings installed during the molding process. There is a plastic ridge between the bearings and a plastic ridge on the outside of each bearing. If you would remove the ridges to make it possible to replace the bearings then you would not be able to hold the bearings in the wheel after you installed new bearings. The wheel most likely would run off the bearings from a loose fit anyway. I am posting a pic of the cut up pulley.



On a side note. Spring fatigue is a issue also. The new idler was a lot stronger than the one I removed. When the engine was idling the belt had a small amount of whip in the long section. With the new idler there is no belt whip at all.

 

[banzaitoyota]

Where did you source the new IDLER? The Stealership, cummins or parts store?

 

[Philip]

I picked it up from a local IH dealer. If you need a number I can post it.

 

[Philip]

3935819 Belt Tensioner



3900679 cap O



The " cap O " is the hold down bolt. I forgot to mention about when I started the thread. It was suggested by the parts man to replace the bolt also. He noted that they had been seeing wear on the original bolt used to mount the idler. When I removed the idler I found that my bolt had worn some. The new bolt also has a shoulder on it just under the head to help align the idler. So if you idler is tracking a little off. Replace the bolt with the number I listed. It is a upgraded bolt for our app's.

 

[Jet Tech]

Every two years or so mine makes a little noise. I remove it, and carefully remove the two bearing seals with a small, dull pick. With the seals removed you can clean then repack the bearing. Reinstall the idler pulley and away you go.



When removing the seals they are retained by a lip on the outer diameter that holds them into a small grove in the outer bearing race. All that holds them in is the size really.



Good luck and enjoy.

 

[Philip]

My bearings were loose and the inside of the pulley was rubbing on the swing arm. So it was time for a new one.

 

[JFitzgerald]

Originally posted by Jet Tech

Every two years or so mine makes a little noise. I remove it, and carefully remove the two bearing seals with a small, dull pick. With the seals removed you can clean then repack the bearing. Reinstall the idler pulley and away you go.



When removing the seals they are retained by a lip on the outer diameter that holds them into a small grove in the outer bearing race. All that holds them in is the size really.



Good luck and enjoy.

Just found this post when searching for info on the tensioner.



I just did the above to mine. I've done the same on my Jeep engine too. Mine was squeeking, so I pulled the belt to see which pulley was the noise maker. It was the tensioner pulley. Re-greased it with synthetic wheel bearing grease. I'll keep an ear on it to see if it's going to last.

 

[sparks57]

The wheel on my tentioner is sticking out towards the block, so that the belt is off the forward side about 1/8"... .



Does that mean I need to replace it?

 

[bflood]

Originally posted by CB_Parker

The wheel on my tentioner is sticking out towards the block, so that the belt is off the forward side about 1/8"... .



Does that mean I need to replace it?

I believe you need a new one. I had the same situation and the replacement fixed it. Got mine from Carquest for $40

 

[sparks57]

Are the car quest ones as good as cummins?