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DRIVE TRAIN TRANSFER CASE

 
Advance Adapter's History of the Atlas Transfer Case

In late 1995, Advance Adapters, Inc., sought to venture into the ultra low 4WD gear business to satisfy the high demand that 4WD enthusiasts were looking for. With various low gear units out on the market already, we wanted to design a product that was unique - something we felt would command a market of its own. We heard of tooling and some components that were available from the early Ford Courier 4WD conversions. We felt that buying the tooling and the engineering would be a fast start for developing a low gear ratio transfer case.

Prototype unit. We called it "the peanut" case because of it's shape.
The tooling was purchased from a gentleman in Ohio. From that point on, we began incorporating new features into the Atlas transfer case. One of the first things to be added were synchronizers to allow "shift on the fly" capability, combined with a new lower ratio by utilizing a full gear set. Included in this new transfer case would be a much needed heavy duty rear output shaft. Based on our acquired tooling, we targeted Wranglers, and early Broncos, which are of the "left hand" drop configuration. As we took into consideration these changes, we soon found that the tooling we purchased would be limiting. We needed a more versatile design allowing us to also include the right hand drop applications (CJ's), as well as early and late model left hand drop applications.

 

With the original reworked tooling, we had produced 5 prototype units that we shipped out to chosen candidates for testing. Reports back from one prime candidate, who has a well know early Bronco, warranted the demand for a totally new design and tooling. After his first few trails we were not surprised to hear of a broken prototype. We immediately received this unit back for analyzing and found that the gear design was marginal.

To quickly get our candidate back on the trails, we shipped out another prototype unit. In the meantime, we began redesigning the Atlas to withstand the abuse that these units would be subjected to. This meant redesigning the case of the Atlas to accommodate larger gears and eliminating the original reworked tooling. Just about the time we had the Atlas I completed, we were assured of being on the right track when the second prototype failed in the burly Bronco. (He had now cracked two "peanuts"!). Fortunately, we were ready to ship the first totally new Atlas I to rescue the "peanut". Continuing close contacts with our Bronco test pilot, we are pleased to report no failures. Now, he says he is breaking other weak links like Dana 60, 35 spline axles!

With the Atlas I in production, Advance Adapters purchased a prototype vehicle of their own to aid in the further refinement of the Atlas I transfer case. This was a 1989 Jeep YJ with a 6 cylinder and Torqueflite automatic transmission. As we started installing the Atlas I into the vehicle, we realized our next set of challenges to overcome. In trying to produce the Atlas I for a wide range of vehicles, we overlooked the front driveline clearance on this particular vehicle. We lacked about a 1/2" of clearance on the Torqueflite transmission pan and had some problems with the shifter linkage serving this vehicle. To remedy these problems, we opted to retrofit a GM TH350 automatic replacing the Torqueflite to allow the Atlas I to be installed in this vehicle.

Knowing that we had to make provisions for front driveline clearance and shifter linkage, we opted once again to do some fine tuning on the Atlas I. We found that the Jeep automatics were going to be a popular application, so we decided to stretch the case 1" from centerline to add clearance for the front driveline. At the same time, we redesigned the shifter linkage to accept a modular twin stick design for the Atlas consumer. As we stretched the unit, we utilized the added space by enlarging the gears, creating a super strong transfer case.

The Atlas II was then created

With the Atlas II now in production, we were presented with some new applications. The Jeep Wrangler TJ series seemed to be a popular application. We were concerned with the shifting mechanisms fitting into the new TJ consoles, so Advance Adapters purchased a 1998 TJ for prototyping the Atlas II and to obtain the proper shift linkage configuration. This application and installation is previewed in the Jeep TJ Installation section of the Atlas Manual.

The Atlas II has proven to answer the gearing requests that the 4WD enthusiast was looking for. Although the unit was originally designed around the Jeeps and early Broncos, now the universal design of Atlas II enables it to fit a wide range of vehicles. Offered are two new super strong ratios of 3.8:1 low range and a 4.3:1 extreme trail ratio.

Since then, numerous upgrades have been incorporated and a wide variety of ratio options have been designed to accommodate any type of drivetrain combination. The Atlas 2 speed ratios include: 2.0, 3.0, 3.8, 4.3, 5.0 & 6.0.

Phases of design and development


peanut prototype

Atlas 1

Atlas 2

Along with these 6 different ratio options, we are now producing our new 4 speed Atlas Transfer Case. Atlas 4 speed ratios include: (1.0:1 / 2.0:1 / 2.72:1 / 5.44:1) OR (1.0:1 / 2.72:1 / 3.8:1 / 10:34:1)

 
 
ATLAS II 2 SPEED TRANSFER CASE
The Advance Adapters gear-driven transfer cases are the ultimate in gearing and strength. With over 7000 units sold, the Atlas 2 speed is the solution for combining both on and off-road performance. The Atlas II from Advance Adapters offers a solid, one- piece case design and is manufactured from 356 T-6 heat treated aluminum alloy. The massive gears are helical cut and synchro-equipped for “shift-on-the-fly” capability. These gears are available in six different low range ratios (2.0:1, 3.0:1, 3.8:1, 4.3:1, 5.0:1, 6.0:1) and are supported by needle bearings, precision matched to 8620 shafts. The 32 spline 1 3/8” output shafts are supported by large taper bearing sets. The Atlas also features a unique twin stick design that offers multiple shift positions for neutral, 2wd high,4wd high,2wd low (rear), 4wd low, 2wd low (front).*front dig*
 
The Atlas 2 speed and 4 speed transfer cases is sure to bring you the utmost in dependability and performance with the best warranty in the industry. The Atlas transfer cases are guaranteed against defects in workmanship and materials for the life of the original purchaser. This lifetime guarantee covers and is limited to gear sets and castings. The remainder of the unit is covered by their limited 1 year warranty.

This Atlas !! is bolted to the ZF 5 speed

FREE speedo cable with any ATLAS Transfercase.

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Part Number
                   PART            

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22-20040
ATLAS II TRANSFER CASE 6.0

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22-20030
ATLAS II TRANSFER CASE 5.0

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22-20020
ATLAS II TRANSFER CASE4.3

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22-20010
ATLAS II TRANSFER CASE 3.8

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22-20050
ATLAS II TRANSFER CASE 3.0

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22-20060
ATLAS II TRANSFER CASE 2.0

 

 
ATLAS II 4 SPEED TRANSFER CASE

 

The 4 speed has essentially two parts. The first is the reduction housing This housing holds a 6 gear planetary assembly that has a low range of 2.72:1 and a 1:1 in high range. We use a planetary assembly that was originally run in a NP241-HD transfer case. This assembly has been rated to withstand 5,555 ft/lb of torque and up to 11,000 lbs gross vehicle weight.
 
The second part of the 4 speed may look the same as the standard 2 speed Atlas, but it does have some differences. The main case of the 4 speed is the same raw casting, but has some machining variations to make it into a 4 speed. The main case functions independently from the front reduction housing and retains all of the normal Atlas features.
 
When all this is put together, you get a new legendary Atlas transfer case with the best combination of gear ratios ( 1:1, 2.0:1, 2.7:1 & 5.4:1 ) or ( 1.1, 2.7:1, 3.8:1 & 10.3:1 ).
 
 
The Atlas 2 speed and 4 speed transfer cases is sure to bring you the utmost in dependability and performance with the best warranty in the industry. The Atlas transfer cases are guaranteed against defects in workmanship and materials for the life of the original purchaser. This lifetime guarantee covers and is limited to gear sets and castings. The remainder of the unit is covered by their limited 1 year warranty.

 

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Part Number
                   PART            

buy now

22-20071
ATLAS II TRANSFER CASE 4 SPEED 5.44

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22-20072
ATLAS II TRANSFER CASE 4 SPEED 10.34

 

 
HEAVY DUTY DRIVE SHAFTS

These heavy duty drive shafts are custom built for B.C. Broncos to our specifications. With full length 7" splines, they are made to work with long travel suspensions without overextending or bottoming out. Assembled with high quality components including Spicer U-joints. All of our drive shafts are custom made per your length just give us a call and it us usually shipped to you within 2 days.

TEC TIP: The most common reason for u-joint failure is due to over tightening the u-bolts, use a short wrench to avoid over tighten the nuts. The transfer case side of the drive shaft torque is 20-25, The differential side of the drive shaft U BOLT torque is 8-15. ( Ford 1977 truck shop manual )

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Part Number
                   PART            

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25-11200
DRIVE SHAFT FRONT

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25-11100
DRIVE SHAFT REAR

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23-00030
U - JOINT SAVER
 

 

 
EXTREME DUTY DRIVE SHAFTS

These heavy duty drive shafts are custom built for YOU. With full length 7" splines, they are made to work with EXTREME long travel suspensions without overextending or bottoming out. Assembled with high quality components including Spicer U-joints.

TEC TIP: The most common reason for u-joint failure is due to over tightening the u-bolts, use a short wrench to avoid over tighten the nuts. The transfer case side of the drive shaft torque is 20-25, The differential side of the drive shaft U BOLT torque is 8-15. ( Ford 1977 truck shop manual )

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Part Number
                   PART            

buy now

25-11120
EXTREME ANGLE DRIVE SHAFT

 

 
U-JOINT SAVER

The U-joint saver keeps the caps on your u-joint. It prevents you from loosing a u-joint cup when you go to install a drive shaft at home It comes in really handy on your spair drive shaft, it really sucks when you go and get your spare drive shaft and a u-joint cap is missing or it is laying there but missing some of the bearings. This is the best tool for the money, it will save you so much aggravation and TIME.                                                                                                

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Part Number                PART                  

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23-00030

U-JOINT SAVER (1310 STANDARD FOR BRONCOS)
 

 

 

 

 

 

 
TRANSMISSION & TRANSFER CASE HARDWARE

When you put in a new drive shaft it is a good idea to use new hardware, The upper bolts we carry are 12 point witch has a smaller head allowing you to use a 5/16 gear wrinch. The lower u-bolt kit are the correct ones for the stock 1310 type u-joint.

      

TEC TIP: The most common reason for u-joint failure is due to over tightening the u-bolts, use a short wrench to avoid over tighten the nuts. The transfer case side of the drive shaft torque is 20-25, The differential side of the drive shaft U BOLT torque is 8-15. ( Ford 1977 truck shop manual )

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Part Number
                   PART            

buy now

25-21000
DRIVE SHAFT BOLTS

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25-30000
SPICER DRIVE SHAFT U-BOLT KIT (2 U BOLTS 4 NUTS 4 LOCK WASHERS)

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25-21010
DRIVE SHAFT BOLT KIT
 

 



BC Broncos -110 Business Drive / PO BOX 69 Ingram, TX 78025
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