• JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler

Transfer Case Parts Guide - Improving 4x4 Capabilities

Posted in How To on July 1, 2010 Comment (0)
Share this

The stock transfer case in your 4x4 will only get you so far. For many this will be acceptable, yet most others will be left wanting. As big tires and increased horsepower come in to play low transfer case gears and heavier-duty output shafts become a necessity. Purpose-built units and dual transfer case setups further improve 4x4 capabilities beyond the imaginable.

Pro Comp
In addition to its vast suspension line up, Pro Comp offers its slip yoke eliminator (SYE) kit and CV driveshaft for all NP231-eqiuipped Jeep YJs and TJs. The kit also fits Cherokee XJs with manual transmissions. SYE and CV driveshaft are sold separately.

Features:
• Shortens the T-case rear output allowing you to run a 4-inch-longer CV-style drive shaft
• SYE and CV driveshaft combine to help eliminate driveline vibration
• Improves driveline angles
• New main shaft is nearly 20-percent larger than factory shaft and will take the added torque of high horsepower and larger tires

For more information, contact:
Pro Comp
(800) 776-0767
www.ProCompUSA.com

Rubicon Express
The Rubicon Express Jeep Wrangler JK transfer case rear flange adapter allows installation of a rear 1310 series CV driveshaft, a much stronger option than the factory driveshaft. Rubicon Express also offers a front output flange for the JK to adapt the front driveshaft to a 1310 series CV driveshaft, as well as ready to bolt in front and rear CV driveshafts.

Features:
• Adapts the JK 8-bolt CV flange to a 4-bolt 1310 series CV flange
• Requires use of a CV rear driveshaft
• Hardware included

For more information, contact:
Rubicon Express>
(877) 493-8697
www.rubiconexpress.com

Stak 4x4
Stak 4x4 offers its Monster B-Box three-speed and Monster Box two-speed transfer cases as replacement units for any 4x4. Customers can choose from a variety of low range ratios, right- or left-hand front outputs, and an optional parking brake affixed to the rear output flange. The B-Box three-speed includes a triple stick shifter and the Monster Box two-speed includes a universal or Jeep TJ-specific twin-stick.

Features:
• Thick-wall, heat-treated, 356 aluminum machined case
• Internals manufactured from heat-treated 8620 gear steel
• Includes heavy-duty 32-spline output shafts

For more information, contact:
Stak 4x4
(915) 584-2400
www.stak4x4.com

Down East Offroad
The Dana 300 flip kit from Down East Offroad allows the venerable Dana 300 transfer case to be installed in many popular 4x4 models, including Jeep YJs and TJs.

Features:
• Flips the Dana 300 transfer case so it can be installed in 4x4s with a driver-side front axle offset
• Will work with any transmission with a 23-spline output and a six-bolt circular tranny-to-T-case mounting pattern

• Includes twin-stick shifter and boot
• Will accept 4:1 low gears and heavy-duty output shafts
• Accepts TJ and YJ speedometer adapters
• Measures 4 inches shorter than an NP231 with a SYE

For more information, contact:
Down East Offroad
(252)246-9440
www.downeastoffroad.com

Advance Adapters
Advance Adapters offers a variety of transfer case options, including its Atlas II two- and four-speed units, and its Orion Toyota Land Cruiser transfer case. Each offers greater strength and increased gearing options compared to stock. Advance Adapters also manufactures a wide selection of transfer case adapters, allowing the Atlas and Orion units to bolt up to most transmissions. Adapters are offered for most popular transfer case and transmission fitments.

Features:
• The Atlas II can be configured with either a left-hand or right-hand front output. The rear output is centered
• Advance Adapters offers adapters to fit the Atlas II transfer case in almost any 4x4
• Gear selection in Atlas transfer case is controlled by a twin-stick shifter. A cable-actuated shifter is also available
• Available low range ratios for the Atlas II two-speed are 2:1, 3:1, 3.8:1, 4.3:1, 5:1, and 6:1

• The Atlas II four-speed transfer case uses a separate six-pinion planetary reduction box for additional gearing choices.
• Four-speed Atlas offers drive ratios of 1:1, 2.7:1, 2.0:1, 5.4:1 or 1:1, 2.7:1, 3.8:1, 10.3:1
• The Orion replaces the three- and-four-speed transfer cases installed in Toyota Land Cruisers
• The cast-iron Orion housing is available as either a kit or a complete bolt-in unit using all new parts
• Orion includes 4:1 low gears

For more information, contact:
Advance Adapters
(800) 655-0787
www.advanceadapters.com

Marlin Crawler
A name synonymous with Toyota gearing products, Marlin Crawler offers many transfer case variables for Toyota owners, including single cases, dual case crawl boxes, and complete ready to bolt in dual case set ups. Marlin Crawler can also provide a wide range of Toyota transfer case shifter parts as well as a heavy-duty output kit and low gear sets. The latest in Marlin’s transfer case parts lineup includes the Land Cruiser Toy Box and the 3.0L V-6 Chain-Drive Crawler Adapter.

Features:
• Land Cruiser Toy Box uses two adapters to mate a ’79-to-’85 Toyota reduction box between an FJ-40 transmission and stock FJ-40 transfer case to create a dual case crawler setup
• Toy Box mounts to any three- or four-speed FJ-40 transfer case
• Maintains factory FJ-40 rear output offset while increasing gearing options
• Toyota 3.0L V-6 Chain-Drive Crawler Adapter is designed for ’88-to-’95 Toyota vehicles with the 3.0L V-6 and chain-driven transfer case
• The Crawler Adapter allows a ’79-to-’95 gear-driven range box to be installed in front of an ’88-to-’95 chain-driven transfer case
• A Marlin Crawler Toyota 3.0L V-6 engine-to-gear-driven transfer case adapter is also required
• Designed to use a 23-spline, top shift style, gear-driven Toyota transfer case or Crawl Box input
• Creates a lower overall crawl ratio

For more information, contact:
Marlin Crawler
(559) 25-CRAWL
www.marlincrawler.com

Trail Tough
Catering to Suzuki 4x4 owners, Trail Tough offers a wide variety of Samurai transfer case parts. Among the available parts are Trail Tough’s low gear kits, rear driveline disconnect, and Mighty Kong transfer case mount/skid plate. Complete professionally-rebuilt transfer cases with the above listed parts are also available.

Features:
• Rear driveline disconnect enables front wheel digs and burn turning and is also a great aid in flat towing the vehicle. Also available for Toyota trucks

• Three Samurai low gear ratios are offered; 4.16:1, 4.9:1, and 6.4:1. Low 4.24:1 gears are available for Suzuki Sidekick and Geo Tracker

• Low gear sets include gears, all seals and gaskets, counter shaft, needle bearings, thrust washers, O-ring, and a new shift sheet

• Mighty Kong transfer case mount/skid plate is recommended when low transfer case gears are installed

• Mighty Kong weighs only 12 pounds and is designed to accommodate drum or disc e-brake upgrades

For more information, contact:
Trail Tough
(877) 789-8547
www.trailtough.com

Offroad Design
The Offroad Design Gen2 Doubler 4:1 Dual Transfer Case system is designed for fullsize 4x4s. The system mates the gear-driven reduction housing from an NP203 transfer case with a complete NP205 transfer case, to create a lower crawl ratio. Offroad Design also offers complete rebuilt NP203 and NP205 transfer cases.

Features:
• Provides an additional low range gear of 2:1, plus your existing NP205 low gear of 2:1 for an overall low gear of 4:1
• Can run in standard 2:1 low gears or switch to 4:1 low
• An all gear-driven transfer case system
• Available with 31- or 32-spline outputs
• Now available for Ford applications
• Custom rotations and hybrid applications are also offered

For more information, contact:
Offroad Design
(970) 945-7777
www.offroaddesign.com

Petroworks
The Petroworks Suzuki Samurai G.R.S. II rebuilt transfer case is a ready to bolt in unit that offers lower gearing than stock. Petroworks also offers the 4.89:1 low gear sets separately for those who want to use their existing transfer case.

Features:
• The 4.89:1 low gears offer a 115-percent reduction in low range and an 18-percent reduction in high range
• Can be built with a twin-stick shifter to access low range gearing in both 2WD and 4WD
• The strong and quiet one-piece gear set is made in Japan
• Using stock Samuari 3.72:1 ring and pinion ratio the G.R.S. II provides a final drive ratio of 66:1. A 100:1 final drive ratio can be achieved using 5.62:1 ratio ring and pinion gears

For more information, contact:
Petroworks
(800) 952-8915
www.petroworks.com

Alloy USA
In addition to its vast Jeep axle parts lineup, Alloy USA has released a yoke conversion kit for ’76-to-’02 Jeep CJ and Wrangler 4x4s. The yoke conversion kit converts the factory strap-style U-joints to a U-bolt design. Alloy USA is exclusively distributed by OMIX-ADA, Inc.

Features:
• Kit includes a new yoke, pinion nut, pinion spacer, pinion seal, U-joint and U-bolts
• Newer U-bolt design is stronger than stock strap-style
• U-bolt design makes it easier to change out U-joint
• Kit includes premium Spicer U-joints

For more information, contact:
OMIX-ADA, Inc.
(770) 614-6101
www.omix-ada.com

Rugged Ridge
Rugged Ridge now offers slip yoke eliminator (SYE) kits for the NP231 transfer case found in ’87-to-’06 Jeep Wrangler 4x4s. These kits are a must when installing a 2-inch-or-taller suspension lift. Rugged Ridge is a division of OMIX-ADA, Inc.

Features:
• A SYE kit eliminates the need to drop your transfer case in order to avoid drive train vibrations that are caused by taller suspension lifts
• The Rugged Ridge SYE kit creates a fixed rear transfer case yoke and accepts a CV-style driveshaft
• CV-style driveshafts reduce driveshaft angle, improve bearing and U-joint life, and reduce driveline vibrations

For more information, contact:
OMIX-ADA, Inc.
(770) 614-6101
www.omix-ada.com

Tom Wood’s Custom Driveshafts
In addition to its premium-quality driveshafts, which are offered for most any application desired, Tom Wood’s Custom Driveshafts offers a wide variety of slip yoke eliminator (SYE) kits. Kits are available for models 207, 208, 231, and 242 New Venture/New Process transfer cases.

Features:
• Super-short conversion kits are available to accommodate short-wheel-base 4x4s
• Super-Duty 231 conversion kits offer versatility in U-joint size for custom or hybrid applications
• SYE kits use a Tom Wood’s-modified output shaft – not do-it-yourself hack and tap
• Super-Duty 231 conversion kits use a new larger and stronger output shaft

For more information, contact:
Tom Wood’s Custom Driveshafts
(877) 497-4238
www.4xshaft.com

Currie Enterprises
Well known for its 4x4 axle assemblies Currie Enterprises also dabbles in the transfer case market with its Dana 300 twin-stick shifter.

Features:
• Available for Jeep CJs and IH Scouts with Dana 300 transfer cases, but also fits many custom/hybrid applications
• Replaces stock single shift lever with two levers to allow independent shifting in the front and rear axles in both low and high ranges
• Simple linkage is fully adjustable for different length transmissions
• Offers ultimate control for adverse off-road conditions

For more information, contact:
Currie Enterprises
(714) 367-2231
www.rockjock4x4.com

Rocky Road Outfitters
Rocky Road Outfitters offers its Trail Creeper low transfer case gears for Suzuki Samurai 4x4s. The company also offers Suzuki driveshaft spacers and adapters to allow use of a combination of Toyota and Suzuki drivetrain components in Suzuki Samurais.

Features:
• Trail Creeper gears are offered in 4.16:1 and 6.5:1 ratios
• Gear teeth have a ground finish that runs quietly
• Trail Creeper gears offer a 269-percent gear reduction over stock
• Gears are 100 percent made in the USA
• Gears are manufactured using 9000-series steel alloy which has a higher strength rating than typical 8620 gear steel
• Complete transfer cases with installed Trail Creeper gears are available

For more information, contact:
Rocky Road Outfitters
(888) 801-7271
www.rocky-road.com

Klune-V
Klune-V offers its extreme underdrive planetary reduction boxes for a broad range of vehicles and drivetrain combinations. The underdrive bolts between the stock transmission and transfer case and acts as a reduction box to create extreme low gearing. A Bronco Dana 20 transfer case is shown with the Klune-V underdrive installed.

Features:
• Available with 4:1 or 2.7:1 ratios designed to further reduce your stock or aftermarket low range transfer case gear arrangement
• Allows for rotation of the stock transfer case to achieve optimal ground clearance or driveline angles
• The 4:1 ratio is ideal for compact trail rigs; the 2.7:1 ratio is best for full-size applications
• Klune-V underdrives offer the option of four-high, Klune-V low range (2.7:1 or 4:1), stock low range, or a combination of the Klune-V and stock low ranges

For more information, contact:
Klune-V
(888) 898-4331
www.klunev.com

OMIX-ADA
OMIX-ADA specializes in the development and manufacture of high value, Jeep automotive accessory and factory replacement components for all models 1941 to present. One of its latest products is its new JK CV driveshaft.

Features:
• Available for ’07-to-’10 Jeep Wrangler JKs
• Replaces stock Rzeppa CV joint driveshaft with unit that uses a common CV-style U-joint-equipped driveshaft
• Provides better strength and operating angle
• Reduces vibration in lifted JKs

For more information, contact:
OMIX-ADA, Inc.
(770) 614-6101
www.omix-ada.com

Trail-Gear
Offering everything in the way of Toyota transfer cases and Toyota transfer case accessories, Trail-Gear is a one-stop shopping locale for Toyota owners. Trail-Gear offers complete transfer cases as well as low gears, transfer case mounts, single- and twin-stick shifter parts, output flanges, adapter plates, and much more.

Features:
• Trail-Gear heavy-duty Bomb Proof transfer case mount kit can handle ultra-low torque of dual transfer case setups
• Offered with Trail-Gear’s world famous Lifetime No Questions Asked Warranty
• Transfer case mounts are stamped out of ¼-inch-thick steel plate, and then welded on a jig to ensure the best fit possible
• Mount kits are coated with clear zinc for a trick finish that will last a lifetime
• Uses polyurethane bushings for long-lasting performance and durability
• Can be used as a stock replacement on ’82-to-’95 four-cylinder transfer cases or with Trail-Gear’s dual case crossmember and other popular dual case crossmembers on all ’79-to-’95 applications

For more information, contact:
Trail-Gear
(877) 494-8697
www.trail-gear.com

Inchworm Gear
Inchworm Gear specializes in Toyota rock-crawling equipment. The company offers parts ranging from its driveshaft flange adapters and top-shift conversion kits to complete single and double Toyota transfer cases.

Features:
• Inchworm’s Lefty Transfer Case Adapter allows a ’79-to-’95 gear-driven Toyota transfer case to be installed in a Toyota Tacoma, 4Runner, or FJ Cruiser
• The Inchworm Lefty is offered as a complete, bolt-in transfer case assembly or as an adapter kit
• Clocking built right into the housing offers ground clearance without changing the shifter angle

• Accepts all available Toyota gear-driven transfer case heavy-duty outputs and low gear sets
• Inchworm driveshaft flanges allow late-model Toyota owners more flexibility in driveshaft choices
• Flanges are offered for Tacoma, V-6 models, and pre-’95 transfer cases
• Inchworm Gear driveshaft flange adapters allow you to bolt up the driveshaft you want to the flange you have

For more information, contact:
Inchworm Gear
(530) 677-8111
www.inchwormgear.com

Novak Conversions
Experts in the fields of engine and drivetrain conversions, Novak Conversion also can supply you with a bevy of quality transfer case parts, including adapters, shifters, low gear sets, master rebuild kits, and more.

Features:
• Shifters are available for NP207, NP231, NP242, Dana 300, NVG241OR Rock-Trac, and Dana Model 20 transfer cases
• NP231 shifter greatly simplifies the shifting pattern for more positive engagement
• Restores and improves shifting action in vehicles with suspension and body lifts
• Shifter knobs and boots are also available

For more information, contact:
Novak Conversions
(877) 602-1500
www.novak-adapt.com

Justice Brothers
Justice Brothers’ Gear Oil Treatment is design to reduce damaging friction and wear in transfer cases that use gear oil for lubrication. The JB Gear Oil Treatment is also said to reduce gear temperatures and improves bearing and gear life.

Features:
• Reduces costly friction and wear
• Smoothes shifting of manual transmissions
• Quiets gear and bearing noises
• Prevents corrosion

For more information, contact:
Justice Brothers
(800) 835-8784
www.justicebrothers.com

TeraFlex
Offering a wide array of transfer case gearing products, TeraFlex can help most 4x4 owners get ahead on the trail. From its Tera Low231 conversion kit to its Tera 2Low kits and low gear sets, TeraFlex has most popular transfer case applications covered.

Features:
• The Tera Low231 conversion kit provides rock-crawling performance without affecting high range gears for daily driver vehicles
• Creates a true 4.0:1 reduction
• Uses a heavy-duty five-gear planetary system
• Every part in this kit is new, with no core charges
• Shift linkage and driveshaft length changes are not necessary
• Tera 2Low kit provides low gearing in 2WD for TJs and JKs
• Tera Low18 and Low20 gears are available in 3.15:1 ratios to fit Dana 18 and Dana 20 transfer cases; also offered for Saturn and Warn overdrives

For more information, contact:
TeraFlex
(801) 288-2585
www.teraflex.biz

J.E. Reel Drive Line
In addition to its vast supply of custom and OE-style driveshafts, J.E. Reel Drive Line now offers heavy-duty 1350 CV driveshafts for the Jeep Wrangler JK. This set up is much stronger than stock and is recommended for lifted JKs.

Features:
• Uses heavy-duty 1350 series U-joints
• J.E. Reel’s 1350 Canyon Crawler upgrade is also available with a stronger spline and slip and Performance Dynamics U-joints
• All front and two-door rear drivelines are made using 0.188-inch-wall tube
• Four-door rear drivelines are made using 0.134-inch-wall tube
• Available for all Jeep Wrangler JKs

For more information, contact:
J.E. Reel Drive Line>
(909) 629-9002
www.reeldriveline.com

Redline Oil
Maintaining your transfer case makes a big difference in how it performs. So does your choice in fluid. Redline Oil manufactures quality fluids for every aspect of your 4x4. The company’s gear oils and ATF will provide your transfer case with proper shifting with excellent wear protection.

Features:
• MT-90 offers excellent gear and synchro protection
• Redline gear oils are well balanced for easier shifting in cold climates
• Redline’s fully-synthetic formulas are created from polyol ester base stocks and offer excellent lubrication under extreme conditions
• Superior shear stability and reduced oxidation compared to other synthetics and conventional gear oils

For more information, contact:
Redline Oil
(800) 624-7958
www.redlineoil.com

JB Conversions
A leader in transfer case gearing products JB Conversions has the slip yoke eliminator, gear set, or output shaft upgrade that your transfer case requires. JB Conversions also offers complete ready to bolt in transfer cases for many model 4x4s, as well as the necessary adapters for conversion projects. From the NP231 to the Dana 300 JB Conversions has the transfer case market well covered.

Features:
• The JB Conversions LoMax NP 205 is completely new unit with a 3:1 low range and heavy-duty case
• No modifications are necessary for vehicle’s originally equipped with an NP205 transfer case
• JB Conversions also offers the shortest NP231 slip yoke eliminator available
• Bigger and stronger Dana 300 4:1 gear sets are available
• JB Conversions also offers a Dana 300 rotation plate, 32-spline front output shaft, and a 32-spline rear output shaft with a parking brake conversion
• Heavy-duty front and rear output shaft kits are also offered for the NP205

For more information, contact:
JB Conversions
(337) 625-2379
www.jbconversions.com

Comments

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Sponsored Links