OzDozer
Senior Member
Michigan S/N
The year of manufacture for a Michigan 175 Series III with the S/N of C6HG9-16 is not listed in my book. However, S/No's C7HG9-17 to C7HG9-29 were manufactured in 1967.
The earliest 6HG S/No's shown are 1965, but these earlier S/No's follow a different numbering pattern, with 1965 manufacture of 6HG S/No machines being 6HG101 to 6HG190.
Many manufacturers "jumped" whole blocks of numbers, to make it appear that they were manufacturing more machines than they actually were, to the "opposition" manufacturers.
In addition, changing the serial numbering system or pattern, to a different style, also ensured confusion amongst competitive manufacturers .. who were always keen to see how many machines a competitor was building and selling.
Allis Chalmers and IHC were notorious for this, but they weren't orphans when it came to the technique.
Add in typos in records, and incomplete records (caused by fires or sloppy recording) and you have a whole new ball game trying to track down S/N info.
Caterpillar have the best S/N records, with their publication "Serial/Product Identification Number Index" book being a very valuable source of info. You can acquire older copies from eBay sellers from time to time, for a reasonable sum, usually around $20-25.
The book I refer to frequently is the AED S/N book. Older copies are useful, but they don't appear often. No S/N book or record is 100% accurate, they all have errors and typos, and you have to cross-check to ensure a degree of accuracy.
The year of manufacture for a Michigan 175 Series III with the S/N of C6HG9-16 is not listed in my book. However, S/No's C7HG9-17 to C7HG9-29 were manufactured in 1967.
The earliest 6HG S/No's shown are 1965, but these earlier S/No's follow a different numbering pattern, with 1965 manufacture of 6HG S/No machines being 6HG101 to 6HG190.
Many manufacturers "jumped" whole blocks of numbers, to make it appear that they were manufacturing more machines than they actually were, to the "opposition" manufacturers.
In addition, changing the serial numbering system or pattern, to a different style, also ensured confusion amongst competitive manufacturers .. who were always keen to see how many machines a competitor was building and selling.
Allis Chalmers and IHC were notorious for this, but they weren't orphans when it came to the technique.
Add in typos in records, and incomplete records (caused by fires or sloppy recording) and you have a whole new ball game trying to track down S/N info.
Caterpillar have the best S/N records, with their publication "Serial/Product Identification Number Index" book being a very valuable source of info. You can acquire older copies from eBay sellers from time to time, for a reasonable sum, usually around $20-25.
The book I refer to frequently is the AED S/N book. Older copies are useful, but they don't appear often. No S/N book or record is 100% accurate, they all have errors and typos, and you have to cross-check to ensure a degree of accuracy.
