belt noise, bearing

[imalumberjack]

ISX 12, I have a squealing bearing? on front of engine. almost positive its a idler bearing or alternator? I have used a stethoscope but can't quite pin point? any good ways? was considering removing front belt (there are two) at least this would eliminate half? I hate replacing parts without knowing.

[Waterloo]

I don't know much about an ISX 12, but on my CM-871 this is the pulley that likes to fail... https://class8truckparts.com/cummins-368...ulley.html

Mine is located on the passenger side, top of motor, up by the AC compressor. Gates makes these too, cost is about half of what Cummins charges. I have found life expectancy on either to be about the same.

Remove the belts and start wiggling the pulleys. If it is a bad pulley, you should be able to find it that way.

[imalumberjack]

(12-29-2018 )Waterloo Wrote:  I don't know much about an ISX 12, but on my CM-871 this is the pulley that likes to fail... https://class8truckparts.com/cummins-368...ulley.html

Mine is located on the passenger side, top of motor, up by the AC compressor. Gates makes these too, cost is about half of what Cummins charges. I have found life expectancy on either to be about the same.

Remove the belts and start wiggling the pulleys. If it is a bad pulley, you should be able to find it that way.

Yes, was thinking it might be that one. At $175.00 bucks from cummins hate to replace two or three and still have a squeal. That $80.00 bucks sounds much better ... I had a different cummins and you could pull a snap ring out of backside of roller and pull two bearings out and just replace them at about $20.00

[Rawze]

(12-29-2018 )imalumberjack Wrote:  ISX 12, I have a squealing bearing? on front of engine. almost positive its a idler bearing or alternator? I have used a stethoscope but can't quite pin point? any good ways? was considering removing front belt (there are two) at least this would eliminate half? I hate replacing parts without knowing.

how do you know it is not a belt squealing?. A bit of soapy water in a spray bottle onto the belts (without soaking the pulley bearings) while its running will make the sound go away if it is a belt.

[Waterloo]

(12-29-2018 )imalumberjack Wrote:  

(12-29-2018 )Waterloo Wrote:  I don't know much about an ISX 12, but on my CM-871 this is the pulley that likes to fail... https://class8truckparts.com/cummins-368...ulley.html

Mine is located on the passenger side, top of motor, up by the AC compressor. Gates makes these too, cost is about half of what Cummins charges. I have found life expectancy on either to be about the same.

Remove the belts and start wiggling the pulleys. If it is a bad pulley, you should be able to find it that way.

Yes, was thinking it might be that one. At $175.00 bucks from cummins hate to replace two or three and still have a squeal. That $80.00 bucks sounds much better ... I had a different cummins and you could pull a snap ring out of backside of roller and pull two bearings out and just replace them at about $20.00

Well, the OEM pulleys on my 871 were replaced when I did my first in frame, the big expensive ones, they had 800,000 miles on them and would probably still be working as engineered. That little one though in the link, I have installed three of those, they seem to fail every 100,000 miles. The one I bought from Gates lasted just as long as the one from Cummins. In fact, when I compared the two, the numbers on the bearing were identical from the same manufacture, just has Gates stamped on the one side and on the box. I think I paid around $30 for the Gates. Local truck repair shop had them in stock. I am sure any good parts store would be able to cross reference the number to save you a few bucks.

[Nilao]

My a/c idler pulley has over 900k miles on it. Replaced my main belt tensioner at 800k miles and the idler at 820k. I have a sqeak in mine but it is the fan pulley...its polished smooth. I plan on removing it and media blasting it to give it a textured surface to grab on to the belt to see if it helps the squeak.

[dhirocz]

For me, it was the combination of the belt, a weakening tensioner and a smooth pulley. Media blasting the pulley helped allot with chirping as the truck was shut off and when the fan kicked on over 1200.

By all means, yes, pull the belts and check each pulley individually. You might even find ones getting rough you didnt know about.

[Baco74]

I replaced bearings on all pulleys, also keep spare set in truck.For both set of tensioners and idler pulleys cast was 125,00 cdn.

[dhirocz]

Sounds like me. I keep one extra of every filter as well as the old belt and pulleys in a box under the bunk.