How do I know what NP205 I have?

The NP205 transfer case is a popular component found in many four-wheel-drive and all-wheel-drive vehicles. Knowing how to identify the specific NP205 model you have is important for maintenance, repairs, and upgrades. This article will guide you through the steps to determine the NP205 transfer case in your vehicle.

Identifying the NP205 Transfer Case

To identify your NP205 transfer case, you'll need to look for the identification tag or casting number. This information is typically located on the side or bottom of the transfer case housing. The tag or number will provide details about the specific model and features of your NP205.

• Identification Tag: The identification tag will have the transfer case model number, such as NP205, as well as other details like the gear ratio, part number, and serial number.


• Casting Number: The casting number is a unique code stamped directly onto the transfer case housing. This number can be used to cross-reference the specific NP205 model.

Once you have the identification tag or casting number, you can use that information to research the details of your NP205 transfer case, such as its gear ratios, input/output configurations, and compatible vehicle models.

Determining the NP205 Model

The NP205 transfer case was used in a variety of vehicles, including Jeeps, Chevrolet, GMC, and Dodge trucks, as well as some SUVs. The specific model can vary based on the vehicle application, so it's important to have the correct identification information.

Some common NP205 models include:

• NP205 4WD: This is the standard NP205 transfer case found in many 4WD vehicles. It typically has a 2.72:1 low-range gear ratio.


• NP205 AWD: The AWD version of the NP205 is designed for all-wheel-drive applications and may have different gear ratios or features.


• NP205 HD: The Heavy Duty (HD) NP205 is a more robust version of the transfer case, often used in larger trucks or vehicles with higher towing capacities.

Knowing the specific NP205 model in your vehicle will help ensure you get the right parts and accessories for maintenance, repairs, or upgrades.

What years did Chevy use the NP205 transfer case?

The NP205 New Process Transfer Case was used from 1971 to 1991. The 1971-79 NP205 was only found mated to the TH350 and the SM465 transmission. For 1-ton vehicles between 1979 to 1984/85, GM used a TH400 and the SM465.

How do I identify my transfer case model?

You can identify your transfer case by looking for a metal tag on the case, checking your vehicle's VIN (Vehicle Identification Number) with a manufacturer decoder, or visually inspecting the case for a model number. The tag is often located under a bolt head on the case and may have the model number stamped on it, but you may need to clean the area first.
 
Method 1: Find the transfer case tag

• Locate the tag: Look for a small metal tag attached to the transfer case, often pinned under a bolt head or hanging from a bolt. The tag may be covered in dirt and grease, so you may need to clean the area to see it clearly.
• Read the number: The tag will have the model number stamped on it. 

Method 2: Use your vehicle's VIN 

• Find your VIN: This is a unique 17-character code found on the dashboard or driver's side doorjamb. 
• Use a VIN decoder: Go to the vehicle manufacturer's website or a trusted online VIN decoder service. 
• Input the VIN: Enter your VIN into the decoder to see a list of your vehicle's factory-installed parts, which will include the transfer case model. 

Method 3: Visually inspect the case

• Check the casting: Look for a cast-in model number on the side of the transfer case itself. This may be a part number, but the tag is the more reliable identifier. 
• Look for specific features: Some models have unique features that can help identification. For example, the NP205 has a distinctive three-bolt rear cover on its idler shaft. 
• Note the shift type: Check the inside of the cab for your shifter. A manual shifter with "4H, N, 4L" positions is a mechanical shift case, while a dial or buttons indicate an electric shift case. 

How do I identify a NP205 transfer case?

To identify an NP205 transfer case, look for its heavy-duty, one-piece cast-iron case and a distinctive three-bolt cover on the rear idler shaft. Other identifiers include a center rear output, a length of approximately 12 inches, and an ID tag, though this can be worn off. The location and specific details of the tag (such as model number) can help confirm the exact model.
 
Physical characteristics
This video shows the physical characteristics of an NP205 transfer case: 28sHigh Gear TransmissionsYouTube · Apr 5, 2019

• Case material: It is constructed of one-piece cast iron. 
• Rear cover: The most reliable way to identify it is by a small, three-bolt cover on the back of the idler shaft. 
• Output shafts: It features a center rear output shaft. 
• Length: The unit is approximately 12 inches long. 

Identification tag

• Location: An ID tag is usually located on the upper front of the case or on the rear near the driveshaft exit. 
• Importance: The tag contains crucial information like the model and assembly number, which can specify details such as the input shaft spline count, shift type, and yolk type. 
• Challenges: The tag is often worn off, so you may need to rely on the physical characteristics listed above. 

Shifter and input

• Shifter: The standard shifter is a single lever that controls two shift rails. 
• Input: The input configurations vary depending on the application (e.g., figure-eight pattern or circular six-bolt pattern). 

How much HP can a NP205 handle?

A stock NP205 transfer case can handle significant power, but a modified one with stronger output shafts can handle up to 1,000 horsepower. The stock versions are already very strong because they are gear-driven instead of chain-driven, making them nearly indestructible. For extreme power applications, a popular upgrade is swapping the factory output shafts for larger 34-spline versions, which is a major factor in increasing its power-handling capacity.
 

• Stock NP205: Is extremely durable due to its full-time, gear-driven design, making it one of the strongest factory transfer cases available.
• Modified NP205: With a swap to stronger, larger 34-spline output shafts, the NP205 can handle up to 1,000 hp and large tires, making it suitable for high-performance applications.