Atlas-4sp-JK : Atlas 4 Speed Transfer Cases Automatic Transmission 2007-11 Jeep JK Wranglers

Atlas 4 Speed Transfer Case: Built To Order: 2007 - 2011 Auto Transmission JK

Advance Adapters has built upon the proven design of the Atlas 2, to create the revolutionary Atlas 4sp. No other transfer case on the market today has 3 separate low range ratios built into a single unit. This transfer case was designed for the off road enthusiast that likes to tackle a large variety of terrain with one vehicle. Selecting one low range ratio that works well for mud, sand and rock crawling, is a compromise but the Atlas 4sp overcomes this limitation. One transfer case that is perfectly suited to any terrain that you may want to conquer.

The 4SP has essentially two parts. The first is the reduction housing. This housing holds a planetary assembly that has a gear ratio of 2.72:1 when in "low" range, and a 1:1 in "high" range. It has one shifter coming out of the top to select the desired range. The planetary is not a synchronized shift-on-the-fly design and must be operated when the vehicle is stopped. (The main case still retains the shift-on-the-fly capability just like the standard Atlas). The reduction housing shifter is designed for a cable shifter.

The second part of the 4SP may look the same as the standard Atlas, but it does have some differences. The main case of the 4SP is the same raw casting, but has some machining variations to make it into a 4SP. The main case functions independently from the front reduction housing and retains all of the normal Atlas features (front and rear outputs controlled independently, and the "front only" option). All of the gears are the same. The front output uses all of the same parts along with the cluster.

The strength of this unit is not an issue. We use a planetary assembly that was originally run in a NP241-HD transfer case. The six planetary gear setup has proven its durability and has been used in countless heavy-duty vehicles. Other attributes to the planetary assembly include a very quiet operation, easy shifting, and low rolling resistance. When all of this is put in front of a legendary Atlas Transfer Case, you get the best combination of gear ratios and reliability.

The 4SP units will fit nearly all applications that the standard Atlas will bolt to. These will include spline counts of 21, 23, 27, 29, 31, 32 and 34. The unit has a circular bolt pattern on the front, identical to the one found in Jeep, Ford & Dodge vehicles. We have a variety of different adapters available to retrofit the 4SP into nearly any application. The twin sticks for the main unit can be either the standard linkage or the cable linkage. The standard linkage is offered in a variety of custom packages available for particular vehicles and can be modified to fit many custom applications. The installation of an Atlas 4 speed should be nearly the same as the standard Atlas 2 speed. The Atlas 4 speed is just a bit longer.

We do not recommend flat towing vehicles equipped with the 4 speed due to the additional bearings used in the planetary housing.

Since every Atlas transfer case is custom built to order, the unit will be customized to your vehicle. Please browse this site or give us a call to determine how to configure the ultimate transfer case, and have us build you one for your vehicles

JEEP JKs 2007 & 2011 (fits both NSG 370 & 42RLE transmissions)

JEEP JKs 2012 TO 2017 (NSG 370, 6 speed manual transmission only)

Introduced in 2007, the JK Wranglers are an ideal vehicle for an Atlas transfer case. These Jeeps were offered with either a automatic or a manual transmission. Both of these transmissions have a 23 spline output shaft and bolt directly to the Atlas transfer case.

Features that you gain when you switch to an Atlas transfer case:

• Low range gearing to rear axle only. This gives you better power and more torque with higher RPM's, and easier steering by not fighting the front power at the front axle.
• The Atlas can be shifter into low 4WD as soon as you need it without stopping.
• The Atlas is synchronized so you can shift in and out of all ranges without stopping.
• You can direct all the power to the front axle, used in racing application more than stock vehicle.

The JK uses flange style yokes on the stock NP241 transfer case. The driveshaft's on these Jeeps also have a long slip to compensate for different drivetrain lengths. These stock drive shafts are light duty and most JK owners do not want to retain them. We do offer a stock JK yoke option for the Atlas and if you do order the Atlas with the stock JK flange yoke option, it is an easy upgrade to a conventional yoke at a later time.

We have listed the most common yoke upgrades that we see most vehicles equipped with and work the best on the Jeep JK Wranglers.

The JK used a cable linkage to shift the Stock NP241. We have designed a cable linkage for the JKs with an Atlas to fit the stock console. This shifter kit uses the stock access hole in the floorboard for the routing of the new cables making, for a clean and easy installation. The installation requires no cutting or modifications to the console. The cable shifter kit for the Atlas 4 peed is PN303008L and is included with this case assembly.

JK's that are installing an Atlas 4 speed will also require a shifter for the reduction housing of the transfer case. We offer a cable option. This linkage is designed to be mounted next to the console. PN344025 is the cable shifter kit.

The JK control module is the only way of keeping all the stock functions operational when upgrading to an Atlas transfer case. This Module lights the dash lights in both high and low range as well as the settings on the ESP when in 4WD and lockers and sway bar disconnect on the Rubicon models. This kit is simple to install with just two plug-in connectors to the Atlas and connecting a power line to your fuse box and a ground to your battery. The JK control module is also included with the Atlas transfer case. Note: This kit is designed for the Atlas 2 speed but can be used on a 4 speed by connecting a additional low range switch to the planetary housing and splicing that switch into the lead from the low range switch from the Atlas case.