Somewhere I got mixed up and thought the second "u2" was the made in USA code... And thought my serial number was only 47433.
Glad to realize my error.
So this is one of the last 6.9s? And probably original engine in a truck made 09/85?
Yep, the id number is:
6.9DU2U247433
Lets break that down for everyone.
6.9D - This indicates a 6.9 Liter Diesel (naturally aspirated). In the 7.3 there was 7.3D and 7.3T, D was N/A, T was a Turbo Block.
U2U - United States Production and which plant. Most for the Navistar Diesels installed in Ford Chassis were produced at the Navistar Plant on Brookville Road in Indianapolis, Indiana. This plant made the 6.9/7.3IDI, 7.3/6.0/6.4PSD Engines.
https://www.google.com/maps/@39.7586345,-86.0702749,603m/data=!3m1!1e3
247433* - This is the +1 serial number for this block.
This is actually a carryover from IH back in the day. They did this with most of what they produced. I recognize the format from my IH Built Cub Cadets.
This is the Kind Code/Model Code/Production Location/Serial Number type format.
For Example:
My IH Cub Cadet has a Serial Number of:
2050660U620571 - The breakdown for these serial numbers are: 205 0660 U 620571
Notice the similarity in the format? We can break this down, and it will help the IDI number make sense.
205 - This is the Kind Code, it indicates an IH produced Cub Cadet Garden Tractor. There are other kind codes for the Rear Engine Riders, and the IH Cadet Lawn Tractors.
These are Garden Tractors (actually mine) and the one on the left without a mower deck is the 1450 I'm referencing.
Kind Code 205:
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This is a Rear Engine Rider:
Kind Code 034:
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This is a IH Cadet Lawn Tractor:
Kind Code 035:
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0660 - This is the Machine Code, which indicates a 1450 Model.
U - This indicates this product was Made in the United States. In the case of IH Cub Cadet Garden Tractors, they were ALL produced at the Louisville Plant. This plant has been demolished and the location is under the runway of the Louisville Airport.
620571 - This is the +1 serial number. It was the 620,070'th unit off the line. Like a lot of IH products the first production serial number was 501. There are some 400 serial numbers that exist. but they are "pre-production" models for testing and development. There is also a listing we have that has the beginning serial number for each month, so we can figure out the month the tractor was produced. (I wonder if there is something floating around for the engines). So, mine was produced December 1977. The first number is 620,313 and the first one for January 1978 is 621,744. So 1,430 were produced in December, 317 per week, 63 per day. So mine being 620,571, that is the 258th unit produced that month. Doing the math, (4.1 days) mine should have been made during the 4th day of production. Looking at the calendar that should have been before lunch on Tuesday, December 6, 1977.
So if you compare the numbers:
6.9DU2U247433
2050660U620571
You can see the "method to their madness" with their numbers. Their serial number has more information embedded than just a serial number.
They use a similar system for their part numbers. At one point in time, the part numbers looked like this:
IH-549930-R1 - This was an IH Part Designation-Part Number-Revision Number. There are times when you are looking for a part, it will come back with a, now use IH-549930-R2, which means they updated the original part, and now this is a revised part.
Now the part numbers look like this:
1807974C94 - This is how the part numbers now look. When the IH name was sold, it was dropped IH, but it still has the Part Number and a Revision Number. So this one is 1807974 for the part number and C94 is the current revision.
**A bonus here- the 1807974C94 Part number is the current IH/Navistar/International part number for a 6.9/7.3 IDI Thermostat and Gasket**. I think I will add this to the parts bin also.....