NV3550 vs AX15 Transmissions : Find the Differences

There is a wide market for transmissions in the automobile industry. Among the renowned transmission types of all time are the AX15 and NV3550. These two have stood the test of time and are still best-selling. So, are these two similar? 

Indeed, it is not easy to choose between the two transmissions. The AX15, for one, is affordable and easily available for an older design, while the NV3550 is quite rare. However, the NV3550 is smoother to shift with reported less noise while driving compared to its counterpart. When it comes to first gear ratios, the NV3550 has 4.01 compared to AX15’s 3.83 making it a better option for off-roading. 

This article gives you a thorough comparative review of the two transmissions to give you a better understanding. Read on. 

NV3550 vs AX15 Transmissions

nv3550 vs ax15

Both the NVV3550 and AX15 are transmissions that were equipped in a wide range of vehicles in the later 90s and early 2000s. They were particularly common in Jeeps. These comparable transmissions have raised numerous debates on which one is the best in terms of the power it can handle. However, the AX15 is significantly cheaper and easier to find. 

In truth, these transmissions are inherently similar in terms of size, torque ratings, number of gears, and the vehicles they were built for.

However, one of the notable differences between the two is their first-gear ratios. For the NV3550, the first gear ratio is 4.01, and 3.83 for the AX15. This means that the NV3550 is slightly a better transmission for off-roading with a higher gear ratio. 

For you to get a better understanding of the dissimilarities that lies between these two transmissions, here is a comparison table. 

Key FeaturesNV3550 AX15
Years in usage 2000-20041989-1999
Length 16.7 inches 16.5 inches 
Models XJ, TJXJ, YJ, MJ, ZJ, TJ
Weight 97lbs 110lbs 
Torque capacity300 lb-ft 300 lb-ft 
Case Cast aluminum With an aluminum mid-plate and cast aluminum case 
Input 10 spline- 1.125” 10 spline- 1.125”
Output 23 spline, flush 23 spline, ½” out 
Transmission Five-speed Five-speed
Price Higher than AX15 Lower than NV3550

NV3550 Transmission Overview 

The New Venture Gear 3550, popularly known as the NV3550 is a 5-speed manual transmission. It was released to be used in XJ Cherokee, TJ Wrangler, and some Dodge pickups.

This transmission was designed to replace the AX15 but did not stay as long as the AX15 in the market before getting replaced as well. In this transmission, the fourth gear performs the role of the direct drive gear while the fifth one is the overdrive.

It comes with all its gears synchronized and helically cut. Moreover, this transmission came in different versions suitable for both 2WD and 4WD. 

Although it is not the toughest in the market, the NV3550 transmission is tough enough to handle most stock applications.

On top of that, on Jeep models, this transmission can handle 300lb-ft worth of torque. Thanks to its adaptability, it can handle difficult engines without putting in a lot of extra work. 

The NV3550 comes factory-compatible with the classic Jeep 4.0 inline-6. Thankfully, there are conversion kits that you can find if you need to connect the transmission with a different model. 

AX15 Transmission Overview 

The Aisin AX15, commonly AX15, made its debut in 1988 being installed in several different Jeeps including MJ Comanche, ZJ Grand Cherokee, XJ Cherokee, YJ, and TJ Wrangler.

It was also available for the Dodge Dakota. The AX15 resembles the R154 transmission that was fitted in the third-generation Toyota Supra Turbo. 

Furthermore, this transmission was a popular choice of its time. It has stood the test of time since even today, many drivers are looking to install it in their vehicles.

It is well-known for its affordability, it is plentiful, reliable, and durable. It was essentially designed for cars that use AMC 258 and the Mopar 4.0 inline-6 engines. 

Just like its counterpart NV3550, the AX15 is a 5-speed transmission with the fourth gear being direct drive and the fifth gear, the overdrive.

Also, it has helically cut gears which are all synchronized. You can find versions of this transmission for both 2WD and 4WD vehicles. When it comes to performance, the AX15 is rated the same as the NV3550 with a torque rating of 300 lb-ft.

How Strong Is the NV3550 Transmission?

The NV3550 came into the market to replace the AX15. It is fitted in the 2000-2005 Jeep models with a 4.0l engine. When it comes to torque rating, this transmission can handle up to 300ft-lbs. 

How Strong Is the AX15 Transmission?

The AX15 is a top-shifting overdrive transmission with fully synchronized gears. This too can handle up to 300ft-lbs of torque. 

Which Transmission Is Better: NV3550 and AX15? 

Both the NV3550 and AX15 are capable transmissions. However, since the AX15 was an older model, it has the advantage of being less expensive. Moreover, compared to NV3550, the AX15 lasted longer in the market. It is therefore easily accessible. On the other hand, the NV3550 is a great choice for off-roading purposes. Overall, they are both excellent choices for your vehicle.


Price is an important determinant when you want to make the final decision on these transmissions. Being the older model, the AX15 has the advantage of being cheaper than its counterpart. Therefore, if you are on a budget, the AX15 is the transmission to go for. 

Unless you use a conversion kit, these transmissions are not interchangeable. The NV3550 comes factory-fitted with NP231 and NP241OR transmissions with a mounting face that features the standard 6-bolt mounting patterns specific to Jeep/Dodge drop-down transfer cases. 

The NV3550 has a higher gear ratio. This makes it best suited for off-roading since the higher gear ratio is good for crawling. 

Final Thoughts 

Overall, it can be concluded that both transmissions are solid options for compatible vehicles. You will be okay with either of them. Your decision will now depend on your personal preferences and your budget. 

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