M923A2 BMY 1988 8.3L 6CTA Cummins Belt Tensioner and alternator pulley

[wilkusmcrecon]

Been trying to get my hands on a Belt tensioner and Alternator Pulley for my 1988 BMY M923A2 8.3L 6cta.

Can you provide me a NAPA part number or a place that can provide the parts needed.

First pulley provided was to small.

would appreciate any help in locating these parts. Need to get her up and running.

Chris W

 

[BKubu]

The alternator pully is a tough one to find. I got one from John Murray from TNJ Murray in Dover, DE. When I got one (several years ago), John told me that he only had one more. Perhaps, he got more or maybe he never sold that one. It is worth a try.

 

[simp5782]

Belt tensioner is in the spreadsheet. 38513

Sent from my SM-G935P using Tapatalk

 

[wilkusmcrecon]

Tracking....

 

[snowtrac nome]

I sent a text to your phone with some pics of the pulley I have there is a number 3918275 stamped on it

 

[Tinstar]

Recommend you ditch the stock alternator and upgrade.
The original ones are notorious for frying and taking out other electrical components with it.
Found out all that the hard and expensive way.

Belt tensioner is easy to find. On eBay also.
Go OEM or Gates makes a good one. Part number already mentioned.

I also have original pulley if your source doesn't pan out.
Edit...pulley sold

 

[wilkusmcrecon]

Had no luck with first two. All were two small and both had a grove that fit the alternator pulley shaft. Mine requires no grove the shaft is tapered out a little wider past the bolt. Let me know if you are still interested in parting with your pulley. PM the requirements and we can it a go.

Chris Wilkinson

 

[Andyrv6av8r]

All were two small and both had a grove that fit the alternator pulley shaft. Mine requires no grove the shaft is tapered out a little wider past the bolt.

Chris Wilkinson

Are you saying that your alternator shaft doesn't have a keyway and key in it?

 

[Motorcar]

Got my alt pulley from the local Cummins dealer, funny they had it for the military alternator.

 

[wheelspinner]

No G. Will kill any future searches.

 

[gringeltaube]

No G. Will kill any future searches.

Took care of that.

 

[Motorcar]

I dug out the receipt for the pulley from Cummins, their part number is 3919390.

 

[wilkusmcrecon]

Shame will not fit my 1988, Seems this one has no key only a slightly larger whole just past the threads.

 

[74M35A2]

Pulley interface is one of several weak points of the stock alternator. Once warbled out, this already weak interface becomes even worse, never to get better. This keyed joint is not commonly utilized anymore, for good reason, it doesn't work well long term through various harmonics.

Upgrading to a civilian unit completely resolves this issue due to a closer tolerance fit with no keyway and high torque nut to pinch the pulley against a shouldered rotor shaft end, in addition to the over-volt issue on M939's when shut down in "wrong" order, improved threaded connections, better cooling, etc....

It is a great way to put this behind you, no matter where you get it from. Many members here have made the change, and I don't recall a single one regretting it. Most say they should have done it sooner, and many order several across their fleet.

It can be disheartening to remove something we think is best designed to be there and install one that looks like it came from a Chevy pickup, but the improved operability becomes apparent almost immediately. I recommend it for nearly all applications expect if being judged in shows for authenticity.