- 15,913
- 22,201
- 113
- Location
- Burgkunstadt, Germany
The attachments below are page numbers 1-4 referred to below. I thought they would be displayed on the page. Hope this works.
View attachment Scan_0003.pdf View attachment Scan_0004.pdf View attachment Scan_0001.pdf View attachment Scan_0002.pdf
It took me a while to get this, but here it is. I took it right out of the -24P for the MEP-803A. It a good read, as it can give you some hints about what parts were available, who can do the repair and why some parts do not have NSN's and how to get what you want, anyway.
We are going to use the pulley for this explanation.
First find the item you want, (the pulley) in the parts manual. Some folks don't know that there are TWO parts TM's for most generators. One for the engine, one for the gen set. So where do you find the Alternator pulley? Engine book, right? Wrong. The engine TM, (TM 9-2815-253-24P) and generator parts TM, (Tm 9-6115-642-24P) cover just what the TM's say it covers. The engine book covers JUST the engine, AND parts that are engine add ons, that are specific to THAT engine. The Generator book covers the entire gen set, and add ons that apply to JUST that gen set. It pays to look at the books, cover to cover, at least one time. For instance, the alternator. Its on the engine. BUT its not in the engine book. Its an electrical device, and is in the generator book.
Page #1 up top is the picture of the alternator. Figure 3 in the book. Look closely. The pulley is listed as Item #1. The mounting hardware is also listed. But the alternator is not listed, even though you can see it. The note besides the alternator picture tell you that the parts breakdown for the alternator is in figure #4. Now that we can see what we want, we need to get informed about that item.
Page #2, up top is the description of the Items called out in the Figure. The pulley is Item #1. Next to the Item number is the SMR code. Thats what we want to get informed about. The SMR code for the pulley is PAOZZ.
Page#3, Skip down to Paragraph #3. Here is the breakdown on the SMR code. The SMR code is a 5 position code. The first two positions of the SMR, (Source, Maintenance and Recoverabilty) code tell you if a part is procured and stocked by the military. Why is that important to a civilian? Well, if an item is not stocked, there were none bought as spare parts. If an item is not stocked, it wont have a NSN, something that might help you find a brand new part from a suppler or in the internet. If a part is not stocked, it may mean you have to make it yourself, from a bunch of parts that are stocked. If a part is not stocked, you may only be able to get it through cannibalization or salvage.
Page #4 shows us the breakdown of the first two letters of the SMR code. The first 7 codes, which start with "P", are all stocked items. They had NSN#s and can be simply ordered, and SHOULD be on hand in the supply system. This is good news for you all, because that means someone probably bought up all these parts as "surplus" and there is a good chance to find them. I will not tell you its easy to find, just that the parts were made available.
The next three codes, start with "K", are all procured, but the code tells you that the item is NOT to be ordered individually. It is part of a kit. Like engine gaskets. If the kit part number and or NSN is NOT listed on page #2, then in the back of the book, is an appendix, when lists these part numbers, and gives you a part number and or NSN, to order the complete kit.
The next 5 codes, start with "M", are procured, but again NOT to be ordered individually. These items are to be ordered in BULK. Rope, sound isolating material, gasket material and such stuff. So where do you find out what the part number and NSN is for this stuff? In the back of the book is an appendix, where all this kind of stuff is listed, and what you need to order to accomplish the job.
The next 5 codes start with "A", and are basically, the same thing as items that start with "M".
The last 4 codes all start with "X" and tell you that there is no way in Hel* you are ever going to find or order the item new. These are the items that have to be "found" by cannibalization or "controlled" exchange. Read that as robbing Peter to pay Paul. The items CAN be ordered, when all else fails. But with special forms, special information and more luck then an Irishman can have. What happens is that a bureaucrat gets your request for the part, and sits on it until he get 10-20 requests, then another bureaucrat submits bids to suppliers, and then another bureaucrat decides who is lowest and another bureaucrat buys the part. Everyone involved in this goat screw has retired or died before it comes to an end. So what it means is cannibalization or theft.
For the perfect example of a XD coded item, look at page #1, up top again. Item #13. The alternator bracket. Now look at page #2, its SMR coded XD. Look at page #4, for the code XD. Not stocked, you will never see this item new. When I needed one, I went to a German metal shop and had one made.
That's the long and short of the first two places in the SMR code. If you see anything other then a P for the first letter, your chances of finding a new part in the box are slim and none. And Slim caught the last bus to Philadelphia a long time ago. The letter K, A or M is not a show stopper, just find the kit and or bulk item. They are listed in the back of the book, in another appendix. If the letter is an X, don't even fool with looking for a parts source. Look for it in a junk yard or parts machine.
Here is a tip or two more. Some parts TM's do not list the NSN in the item description. Do not assume, all is lost. Go to the back of the book, and find another appendix, (yes, another appendix) that lists the part numbers, and gives the NSN for each part number, IF IT HAS ONE. Not all parts do.
If you look in a parts TM, and can not find the item you are looking for, start again. Its there. I promise. Also try looking in the OTHER parts TM, IF there is one. Not all gen sets have been divided into engine and gen set books. Most gen sets, MEP-014A, up to MEP-006A, have only one parts and maintenance book. Its there, you just have to look! If you need practice, find the throttle control cable in the MEP-006A book. Get a bottle of eye drops first.
Why do some parts have an NSN, and some don't? Well, why give a part a NSN, if you never need to order it? Yep, the inner parts to a circuit breaker for insistence, are never going to be ordered. Why? Its just not worth it. Assigning a part a NSN, and stocking it, cost big bucks. More money then you or I make a year. Or if the Item is part of a kit, why give the individual parts NSN's?
If you have managed to stay awake this long, take the time to look through a parts manual and find some of these SMR codes, and look at the parts that are "different".
Oh, this is only the first two letters of the five letter code. I find it hard to believe anyone wants to hear about the last 3 positions of the code mean. Read the book, and if anyone really wants to know more, I will explain.
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and there are brand new ones on the giant auction site that starts with e ends with y for about 170 dollars if you need one. Tempted to buy one as a spare myself.