What Do These Numbers Mean in New Holland?

To save time and reduce the return, your supplier must ask you for a number when you order parts for your tractor. You may be in a flurry and find the number on the body with sweat; after all, your project DDL is coming. We get it, this article shares useful ways to help know the meaning of your New Holland tractor.

Actually, each code tells a specific story about your tractor, for example, your equipment’s built time, model, origin, and what parts you’ll need. Let’s explore these numbers and know how to use them to keep your machine running.

Where to Find Numbers on Tractors

Ford and New Holland have placed serial numbers, model IDs, and date codes on the transmission bellhousing flat, located behind the starter. You’ll often find them stamped—not raised—into the metal, so they can be tough to read if there’s dirt or corrosion.

Some tractors have multiple ID plates. Check the upper right corner of the transmission, inside the hood near the front, or on the left side of the frame. The exact spot often depends on the tractor’s size, age, and type. With long-term use, you can clean the area gently, and you should spot several number groups.

How to Decode the Date Code

The date code is probably the most useful number for figuring out when your tractor was actually assembled. The unit number is coded for the year, month, day and shift when the tractor was assembled. Now, we take a typical date code like 6L23B as an example, and show the way to decode it.

• 6 = Year (could be 1986, 1996, or 2006 depending on context)

• L = Month (December—letters A through M represent January through December, with “I” skipped)

• 23 = Day of the month

• B = Shift (A = morning shift, B = afternoon shift)

According to the above, we get info: 6 is the year, L is December, and 23 is the date, and B is the day of the shift. So this tractor was assembled on December 23, 1996 (or ’86 or ’06) during the afternoon shift. To pin down the exact decade, look at the branding. If it is properly badged as a New Holland, it is a 1996.

What the Model Code Tells You

Okay, in this part, we’d like to use EM4H4C coad as an example. This number is the model number. This alphanumeric code represents the tractor’s model and configuration. The first letter E often indicates the general class or family. In many cases, models starting with “E” fall into the 5600/6610 class.

These model codes are stamped on the transmission housing and help dealers identify exactly which variant you have. If you’re buying parts, the model code matters just as much as the model name—sometimes more, since production changes happened mid-year.

Identifying the Serial Number

The serial number can be thought of as your tractor’s ID.  Even if many tractors share the same model name (such as the Boomer 40), the serial number identifies your exact machine. Okay, let’s get to know the serial number, which includes both numbers and a letter suffix generally. We share the number “355273M” as an example; the letter at the end indicates where the tractor was manufactured. An “M” means it was built in Mexico. You can try to identify your tractor in this way.

Engine Numbers vs. Tractor Serial Numbers

Don’t confuse the engine serial number with the tractor serial number. The New Holland tractor serial number (or PIN) identifies the entire machine. The engine serial number identifies only the engine and is needed for internal engine components.

For example, a number like NA639484 is typically the engine serial number, while something like 82850639 is often an engine part number. NA639484 is likely the engine serial number, which is different than the tractor serial number. These numbers are stamped on the engine block or pan rail, usually on the right side.

When you need engine-specific parts—like pistons, gaskets, or internal seals—use the engine serial number. For everything else, you can choose the tractor serial number.

How to Find the Right Parts with Your Numbers

Once you’ve decoded or mastered your tractor’s numbers, put them to work. This serial and date information helps prevent costly mistakes.

Suppose you’re looking for a New Holland lookup to find compatible parts. You enter your model (6610S) and serial number (355273M). The system may display two different fuel pumps—one for serial numbers manufactured before a specific date, and one for those manufactured after. Your date code confirms which one fits.

Parts suppliers and repair shops rely on this data. If you show up without it, you’re guessing. And guessing costs you time and money.

What to Do If You Can’t Find the Numbers

There are many reasons that you can’t find it, such as the serial plate being missing, corroded, or buried under decades of grease and paint. If you’ve searched every common location and still come up empty, you have a few options:

Contact a New Holland dealer

They have access to internal databases and can often provide the manufacturing year based on the serial number. 

Cross-reference engine numbers and part numbers

This way will help narrow down the model and year range.

This can happen with “grey market” imports, specialty models, or very old tractors with non-digitized records. In these cases, contacting a dealer is your most reliable option.

Why the Exact Model Variant Matters

Some series have been upgraded, such as the 6610 series. If you’re working on one of the 6610 series, know that these models evolved. The first was a 6610, then upgraded the steering and called it a 6610 II, then came the 6610s, which had a different fuel system and were manufactured in Mexico. Later versions had emission-controlled engines and different hydraulic pumps.

Always refer to your tractor as the exact model variant (like “6610S” instead of just “6610”). That one letter makes a big difference when ordering parts or looking up specs.

Conclusion

According to the ways mentioned above, decoding the numbers on your New Holland is not a big challenge for you guys. You can know when it was assembled from the date code, and identify the configuration from the model code. Importantly, you’d better remember your serial number, it’s your machine’s unique ID, and the engine number covers internal engine components. A practical tip: you can keep a photo of your ID plate on your phone. For example, write down the serial number, model code, and date code somewhere safe. When you need parts or service, you’ll have everything ready. Trust me, it will help a lot.