Cummins ISM Alternator belt pulley

[Guest mu2drvr@aol.com]

2005 Signature, Cummins ISM. After stopping for the day (Redding CA), discovered alternator belt broken. Further investigation found pulley to right of alternator had seized bearing. Took mount and pulley to Freightliner for bearing replacement. BAD NEWS: when bearing seized it welded the itself to the spindle mount. Also hogged out inside of pulley. Cummins has told me they can't identify these parts as they were provided / installed by Monaco. REV group was unable to access their Monaco system for tech reasons all day, so no help there yet. Freightliner shop told me this mount would be called a 'fan drive" if it were mounted in a truck. You can see on the pulley where a fan would be installed. In the coach application all this pulley does is rout the alternator belt down to the crankshaft. No response yet from salvage yards. What initially looked like a simple repair has turned into a parts sourcing nightmare. Any ideas ??

Thanks,

Steve A

2005 Signature, Cummins ISM

2020 Ford Escape Hybrid

[DavidL]

Pop the old bearing out and look for part numbers.  Google part number and buy the bearing.

You might need a hydraulic press or good control of a large socket / hammer.

If no part numbers, just measure the OD and ID and find the right bearing.

If truly you can't find the assembly and the outside of the bearing spun, it's possible a machine shop can bush or weld / lathe the pulley so the original bearing will fit again.

From the pics, it just looks like the bearing failed which is pretty easy to replace.

Edited July 20, 2022 by DavidL

[Dr4Film]

Is it possible to mount a different idler pully to that location and install a serpentine belt that would be of the proper length needed to fit all of the pulleys?

[cbr046]

Don't forget to match the number of ribs if you replace the pulley itself.  On autos I think some ribs are v shaped while some are u shaped. 

- bob

 

[Guest mu2drvr@aol.com]

The iron part that mounts to engine block and provides a spindle for this pulley is not serviceable. Not sure about reworking the pulley itself for another bearing, it is pretty trashed. Going to investigate rerouting with a different (shorter) belt, but may find interference issues.

Just heard back from REV. They tell me these are Cummins parts! Cummins is where I started.  Aaahhhccckkk ...

My engine specifics:

ISM-02-500,   SER# 35089957

[Gary M]

I’m asking the rest of you a dumb question.

So that pulley and mount is something that Monaco had to have made and is not part of the Cummins engine?

Inquiring minds want to know.

[Dr4Film]

Gary, it is my understanding that the pulley was used to mount a fan when the engine is mounted normally in a truck that had a front mounted radiator.

[Gary M]

8 minutes ago, Dr4Film said:

Gary, it is my understanding that the pulley was used to mount a fan when the engine is mounted normally in a truck that had a front mounted radiator.

So that is a Cummins part! And I assume not available. I’ve had to repair many frozen bearings to pulleys in my line of work. Soak um and heat pulley while pressing bearing out. Worse thing is ya destroy pulley but the worst for me was to take pulley to machine shop and bore out and re-sleeve. But he’s  kinda stuck.

Edited July 20, 2022 by Gary M

[vito.a]

Yes.  This is definitely a Cummins part. 

One of the aftermarket companies was reproducing it also.  I think it was Dayco.  A good truck parts man would know.  

Edited July 20, 2022 by vito.a

[streetrodder]

a good machine shop can fix this hands down!!!!

might have to travel to chico I know of one in Marysville

[Jdw12345]

Ouch!

so in other words we should try and lube that bearing, I have an ISL so I’ll have to look at it. 
A couple of years ago I removed all of the idler pulley bearings on my Powerstoke and repacked them, truck now has 371’xxx miles on original pulley bearings. 

[engine103]

I don't know if your still in Redding but a couple of years ago with my ISM I had a major electrical break down and was recommended to A&N Diesel LLC who works on Monaco and Beaver Coach. Name is Steve Ashe # 530 221 0460. We were on a trip through California, he dropped his other jobs and spent a week sourcing and repairing. I was surprised at his invoice, much lower than expected. Might be worth a try.

[timaz996]

32 minutes ago, vito.a said:

Yes.  This is definitely a Cummins part. 

One of the aftermarket companies was reproducing it also.  I think it was Dayco.  A good truck parts man would know.  

My experiences with Cummins has never been good. Customer service is not something they care about. Cummins use to sell the ISC Caps pump in there separate pieces just as it is removed from the engine. They decided to make a whole lot more money by only selling the complete pump because they had so many failures. The failure part of the pump was $300-350. The whole pump is $6500. Not my favorite company.  

[Tom Whitlow]

I second that opinion of Cummins.

[Ivan K]

I find it amazing that they made the routing so complex because of a fan that you don't even have. Our alternator is turned by water pump pulley and nothing else in the way. Wonder if it is something you could do instead. Don't have a better pic handy at the moment.

[Guest mu2drvr@aol.com]

Ivan: Is your engine ISM ?? Interesting .. Does it use 8 rib belt or V-belt, and how does it tension ??

[Dr4Film]

Steve, if you look at his engine, notice that it doesn't have a serpentine belt. Not sure what engine he has.

[Ivan K]

31 minutes ago, mu2drvr@aol.com said:

Ivan: Is your engine ISM ?? Interesting .. Does it use 8 rib belt or V-belt, and how does it tension ??

Steve, yes it is an ISM500. It's got two independent short serpentine belts. The AC belt has a tensioner, alternator belt is tensioned by alternator's angle, just like cars used to be. I don't remember how many ribs but if you thought that it was important, I would go look.

[timaz996]

He has an ISM as you can see in this picture.

[Guest mu2drvr@aol.com]

Ivan: Where your water pump is mounted I have just an idler pulley. The alternator mount has no movement.

[Ivan K]

1 hour ago, mu2drvr@aol.com said:

Ivan: Where your water pump is mounted I have just an idler pulley. The alternator mount has no movement.

Yes, I see that. Yours looks like this one and the fan hub is definitely Cummins part. This is from their service manual. 

 

Just curious, is it the original motor? Just because of the markings on it.

Edited July 21, 2022 by Ivan K

[Tom Whitlow]

I have the ISM and both my belts have tensioners.

[Dr4Film]

3 minutes ago, Tom Whitlow said:

I have the ISM and both my belts have tensioners.

Snowflakes for sure. There is no standard when it comes to Monaco or now Cummins.

[Guest mu2drvr@aol.com]

Ivan: I assume this to be the original engine. I am 3rd owner. Unable to read labeling on valve cover, REV gave me the engine serial number. Your diagram part #5 is exactly what I’m looking for.

[Ivan K]

Steve, unfortunately my manual does not list a part number for #5 but if you get an account with quickserve for your SN, it might show it. No numbers on the hub casting I suppose either. I don't have the best experience with their parts department either but a competent sales person should be able to locate it. Here is one but not sure about the stand off. I bet they are very proud of it...