John Deere, like other engine manufacturers, uses its unique terminology and provisions to mark its products and assign part numbers. Understanding this marking system and categorization is critical to part number identification, which is then used to select rebuild kits, components, and maintenance parts.

A typical engine serial number looks like TO4045T123456. To better understand this number, it will be divided into several parts. The first segment is the initial two letters “TO”. These two initial letters indicate two things: – one, in which country it was manufactured and, secondly, if it is Powertech or not Powertech.

All John Deere engines manufactured in Dubuque, Iowa, USA, are preceded by the letters “TO”, all engines preceded by “CD” are manufactured in Saran, a factory located in the Loiret area of ​​France, and all engines are manufactured in Torreón, Mexico, they are preceded by the letters “PE”.

The next set of numbers in the John Deere engine serial number are four (4) or (5) numbers and letters. In our example, this refers to “4045T”. This can be subdivided into “4045” and “T”. The 4045 indicated that this is the 4045 model. The initial “4” indicates that it is built with four (4) cylinders. The “T” after the engine model number indicates that the engine has an attached turbocharger and therefore this is a turbocharged engine. This factor is significant as turbocharged engines are designed differently from non-turbocharged engines. Most importantly, the parts cannot be interchanged between these two types of engines.

The last set of six (6) numbers is the sequential number of the engines when it leaves the assembly line. If this number is 123456, then the next serial number for the next engine on the same assembly line will be 123457. This will continue until John Deere decides it is time to upgrade or build another model.

There are many variations of the old serial number. Model 4045T can be marked as 4045D. Here, the “D” symbolizes that the engine is a diesel engine (some of the early John Deere were built to run on gasoline), and that is naturally aspirated, meaning it does not have a turbocharger. So this serial number could have been TO4045D123456 and this would have been totally different from TO4045T123456.

The 4045 in serial numbers can also be 3152, 3164, 3179, 3029, 4202, 4219, 4239, 4039, 4276, 6303, 6329, 6059, 6414, 6068, 6414, 4270, 6404, 6466, or 6076. They can be followed by a “D”, a “T” or an “H”

The problem often arises of how to identify which motors are PowerTech and which are not. This can be remedied by further dissecting the John Deere serial number.

For engines made in Dubuque, Iowa, USA (TO engines), all engines with a sequence number greater than 700,000 are Powertech engines.

For engines made in Sarran, France, (DC engines) all engines with a sequence serial number greater than 500,000 are all Powertech engines.

However, on the contrary, all John Deere engines manufactured in Torreón, Mexico (PE engines) are PowerTech engines. This sequence serial number began with one thousand (1000). Therefore, all PE PowerTech motors will have a sequence serial number of one thousand (1000) and more.