Suggested Tools:

• Welder (MIG or TIG)• Socket: 14mm• Allen Socket: 8mm • Ratchet• 14 mm Combination Wrench• Torque Wrench• Snap Ring Pliers• Wheel Bearing Grease• Brake Cleaner • Hammer• Slip-joint Pliers• Permatex® Gear Oil RTV Gasket

Maker (or Equivalent)• Angel Grinder • Die Grinder W/ Cut-Off Wheel• Permatex® Blue Threadlock

CAUTION: Safety glasses should be worn at all times when working with vehicles and related tools and equipment.

Inchworm Tacoma Dual Case Adapter

Installation Instructions

For additional copies of these and other instructions go to:www.lowrangeoffroad and click on the “Instructions” tab.

Instructions Created by an:

Parts Identification

Crawl Box Case (C)

Counter Gear Assembly (C)

Main Shaft Needle Bearing (C)

Input Shaft (C)

Low Range Gear (C)

Shifter Fork (C)Shifter Shaft (C)Input Needle Bearing (C)

Thrust Washer (I)

Snap Ring (I)

Dual Case Adapter (I)

Dual Case Coupler (I)

Contents of

Hardware Kit(I)

(I) = Inchworm Supplied Part(C) = Customer Supplied Part

Background Information

We strongly recommend this job be done in a clean dust free environment and that all parts be clean and free of any dirt, grease, or debris PRIOR to beginning the job.

Additionally, it is recommended that you double check each part DURING the assembly process to insure a clean, quality installation. For example; additional cleaning should be done before applying bearing grease, gasket sealer, dry fit gaskets and when putting any parts together that have close tolerances.

Step 2Apply a good quality wheel bearing grease to the main shaft needle bearing.

Step 1Install the main shaft needle bearing on the duel case coupler.

Step 3Install the dual case coupler inside the low range gear.

Step 4Install the detent ball in the hole shown here.

Step 5Apply some grease to the thrust washer.

Tech Tip 4Detent ball properly positioned.

Step 6Install the thrust washer on the dual case coupler with the greased side down.

Tech Tip 6Insure that the notch in the thrust washer aligns with the ball.

Step 7Install the low range gear assembly in the dual case adapter as shown. It will not go all the way with out some force.

WarningPlease use extreme caution with the next steps. There are several ways to press the dual case coupler into the dual case adapter bearing. We will show one option and explain another.

Step 8Turn the dual case adapter over and place it on a solid workbench resting on the dual case coupler.

Step 9Tap the dual case bearing (and dual case adapter) downward using a hammer. Be sure to tap gently, striking the inner bearing race ONLY.

Caution: NEVER press or tap on the outer bearing race, bearing cage, or the soft aluminum dual case adapter.

Option 1 (Without a press)

Inner Bearing Race

Outer Bearing Race

Bearing Race Cage

Step 11It will likely be necessary to use a soft punch to drive the bearing the last little bit. Strike the inner bearing race ONLY.

Step10Evenly distribute taps around the circumference of the inner bearing race, driving the bearing down on the dual case coupler.

Option 2 (With a Press)

Tech Tip 11Position the dual case adapter in a press. Select a press quality tool that is round and is small enough to contact the inner bearing race, yet large enough to fit over the dual case coupler. Press the inner bearing race until the snap ring can be installed. (See Step 12)

Inner Bearing Race

Dual Case Coupler

Outer BearingRace

Step 12Install the snap ring using snap ring pliers.

Tech Tip 12This shows the snap ring properly installed.

Caution: DO NOT press against the outer bearing race, bearing cage or the aluminum dual case adapter.

Dual Case Adapter

Step 14Apply some grease to the input needle bearing.

Step 13Turn the dual case adapter over on the work bench.

Note: Be sure to place a cloth under the adapter for protection.

Step 15Install the input needle bearing inside the dual case coupler.

Step 16Mark the shifter shaft as shown. The shaft should be marked then cut about an 1/8” above the 1st groove (or a distance equal to the space between the grooves).

Step 17Using an air cut-off tool, cut the shifter folk as shown.

Note: It is best to leave a little more material than you think is needed at first. You can alway grind a little more off if needed, later.

Modifying the Shifter Shaft

Tech Tip 18This is what the shifter shaft should look like when finished.

Step 18Using a side grinder, smooth any rough edges or burrs, and make a chamfered edge all the way around the shaft.

Small Chamfer

Step 19Test fit the shifter shaft by placing it in the dual case adapter as shown. Then view the shaft though the detent ball hole as shown in the next picture.

Step 20The shifter shaft groove should be centered in the detent ball hole. Grind a little more off the end of the shifter shaft if needed. Once you are satisfied the shifter shaft fits properly, remove it and set it aside.

Step 21Position the supplied piece of square stock as shown and weld it into place.

Modifying the Shifter Fork

Tech Tip 21Weld the square stock in the locations shown.

= Shows Weld Points

Step 22Smooth all welded surfaces using a flap disc (or Equivalent) in an air grinder.

Step 24Align the roll pin with the hole in the shifter shaft.

Step 23Place the shifter fork in a vice and install the shifter shaft as shown.

Note: Insure the notches are oriented as shown here.

Installing the Shifter Shaft in the Shifter Fork

Step 25Drive the roll pin into place using light taps with a ball peen hammer. See next Tech Tip for proper roll pin installation.

Tech Tip 25The roll pin should be flush with the shifter fork.

Step 26Apply some grease to the shifter shaft as shown.

Step 27Apply some grease to the shifter fork top and bottom, 4 locations.

Installing the Shifter Shaft and Fork Assembly

Step 29Install the shifter rod, fork and collar assembly as shown.

Step 28Install the shifter collar in the shifter fork.

Note: The shifter collar can fit two ways. It does not matter which.

Tech Tip 29Shifter rod, fork and collar properly installed.

Step 30Install the input gear assembly into the low range gear assembly.

Step 31Install the counter gear assembly as shown.

Step 32Position the crawl box case on the work bench as shown.

Note: Place a cloth on the bench for protection.

Tech Tip 32A p p l y i n g s o m e b l u e P e r m a t e x threadlock to these treads is strongly recommended.

Installing the Crawl Box Case

Apply Threadlock Here

Step 34Turn the crawl box case over and temporarily install it on the dual case adapter. This is simply a test to see that all parts fit properly before final assembly.

Note: Be sure to align the studs and bearings as shown. D0 NOT FORCE

Step 33Install the (5) studs in the crawl box case as shown.

Note: If the studs do not go all the way in by hand, tighten them with a pair of pliers. Be sure to grip the studs in a non-threaded area so as not to damage the threads.

Step 35Once the crawl box is in place, inspect it carefully to see that all parts fit together properly and spin freely. Once you are satisfied the parts will fit together properly, go on to the next step.

Step 36Remove the crawl box case.

Step 39Reinstall the crawl box case back on the dual case adapter as shown.

Note: Double check the dual case adapter for cleanliness as well.

Step 38Install the supplied gasket as shown.

Note: We do not recommend using gasket sealer here. This is simply a dry fit.

Step 37Clean the gasket surface with brake cleaner and a cloth.

Step 40Install the counter gear assembly snap ring.

Note: You will need to lift up on the counter gear assembly to install the snap ring.

Step 43Snug these (2) bolts for now. Not much more than finger tight.

Step 42Start the (2) supplied (M10X1.25X40mm) bolts.

Note: Be sure to include a lock washer and flat washer with each bolt.

Step 41Install the snap ring on the input shaft assembly.

Note: You will need to lift up on the input shaft to install this snap ring.

Step 44Turn the transfer case assembly over.

Step 46Finish tightening, then torque the (2) bolts you installed in Step 42 to 29 ft. lbs.

Step 45Install a flat washer, lock washer and nut on all (5) studs. Tighten these nuts in a progressively tighter criss cross pattern until 29 ft. lbs. is reached.

Tech Tip 47BThis picture shows the single alignment mark on the transfer case adapter. This mark can be positioned on each of the degree marks on the dual case. This mark can also be aligned exactly between each of the degree marks (5° increments) for an even wider range of positions if needed.

0°10°

10°20°

20°

30°

30°

Tech Tip 47ATo help orient the dual case adapter with the transfer case adapter there are alignment marks cast into each component. This picture shows the alignment marks on the dual case adapter. They are in 10° Increments to accommodate a wide range of applications.

Step 47Place the transfer case adapter on the work bench as shown.

Step 49Apply a thin coat of Permatex Gear Oil RTV Gasket Maker (or equivalent) as shown.

Installing the Transfer Case Adapter

Step 48Clean the area around the bolt holes with a good quality degreaser such a Brake Clean.

Tech Tip 49Apply gasket maker in the area between the red circles.

Step 50Place the dual case on the work bench as shown.

Step 51Turn the transfer case adapter over and install it on the dual case making sure the alignment marks are aligned as shown in the NEXT picture.

Step 52Alignment marks positioned on 0°.

Note: We used the 0° mark for our application. But you can use any one of 13 different positions (5° increments) that best fits your application. See Tech Tip 47A and 47B.

0°

Step 53Insure that the transfer case adapter and the dual case adapter are going together evenly. This is a very snug fit. If you attempt to put these two parts together using excessive force, damage could result.

Step 54It may be necessary to turn the assembly over and push down on the dual case to have these two pieces go together.

Tech Tip 54This shows the transfer case adapter and the dual case adapter properly fitted together and the marks aligned.

0°

Step 56Install the bolt in one of the holes that are aligned properly.

Note: It may be necessary to SLIGHTLY rotate the transfer case adapter to align the holes.

Step 55Apply blue Permatex® threadlock to the threads of one of the M10X1.25X25 allen head bolts.

Step 57Install the remaining five bolts as shown in steps 55 and 56 and torque all (6) bolts in a progressively tighter criss-cross pattern until 29 ft. lbs. is reached.

Congratulations!All done. We hope these instructions were helpful. If you have suggestions on how we can improve our instructions (or products) please email us at sales@inchwormgear.com

As always, If you experience any difficulty during the installation of this product please contact Inchworm Gear Technical Support at 530-677-8111 during working hours. Thank you for purchasing from Inchworm Gear.

These instructions are designed as a general installation guide. Installation of many Inchworm Gear products require specialized skills such as metal fabrication, welding and mechanical trouble shooting. If you have any questions or are unsure about how to proceed, please contact our shop at 801-805-6644 or seek help from a competent fabricator. Using fabrication tools such as welders, torches and grinders can cause serious bodily harm and death. Please operate equipment carefully and observe proper safety procedures.

Rock crawling and off-road driving are inherently dangerous activities. Some modifications will adversely affect the on-road handling characteristics of your vehicle. All products sold by Inchworm Gear are sold for off road use only. Any other use or application is the responsibility of the purchaser and/or user. Some modifications and installation of certain aftermarket parts may under certain circumstances void your original dealer warranty. Modification of your vehicle may create dangerous conditions, which could cause roll-overs resulting in serious bodily injury or death. Buyers and users of these products hereby expressly assume all risks associated with any such modifications and use.

Revised 05/06/14© Copyright 2014 Low Range Off-Road, LC       All Rights Reserved