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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• Blue Permatex® Threadlocker

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

Inchworm Gear Clockable Toyota Dual Transfer Case Adapter Kit, 21 or 23 Spline SKU# TCASE-IW-300-000

Installation Instructions

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

Instructions Created by an:

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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)

Front Dual Case Adapter (I)

Dual Case Coupler (I)

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

Contents of Hardware Kit *(I)

Rear Dual Case Adapter (I)

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Background Information

For best results throughly clean all parts and assemble them in a dust free environment.

Additionally, it is recommended that you double check each part DURING the assembly process to insure a clean, quality installation.

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

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

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

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

Step 5 Apply some grease to the thrust washer.

Tech Tip 4 Detent ball properly positioned.

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Step 6 Install 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 7 Install the low range gear assembly in the front dual case adapter as shown. It will not go all the way with out some force.

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

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Step 8 Turn the front 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 11 It will likely be necessary to use a soft punch to drive the bearing the last little bit. Strike the inner bearing race ONLY.

Step10 Evenly distribute taps around the circumference of the inner bearing race, driving the bearing down on the dual case coupler.

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Option 2 (With a Press)

Tech Tip 11 Position the front 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 12 Install 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

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Step 14 Apply some grease to the input needle bearing.

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

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

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

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Step 16 Mark 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 18 This is what the shifter shaft should look like when finished.

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

Small Chamfer

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Step 19 Test fit the shifter shaft by placing it in the front 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 21 Position the supplied piece of square stock as shown and weld it into place.

Modifying the Shifter Fork

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

= Shows Weld Points

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

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

Step 23 Place 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

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Step 25 Drive 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 26 Apply 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

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

Step 28 Install the shifter collar in the shifter fork.

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

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

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

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Step 31 Install the counter gear assembly as shown.

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

Note: Place a cloth on the bench for protection.

Step 33Apply ing some Blue Permatex® Threadlocker to the SHORT treaded end of the supplied stud.

Installing the Crawl Box Case

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Step 34 Install the stud in the crawl box case with the short treaded end of the stud oriented downward.

Step 35 Tighten the stud using the double nut approach.

1. Install 2 nuts on the stud

2. Hold the bottom nut and tighten the top nut

3. Snug the stud by tuning the top nut clockwise

4. Remove both nuts.

Caution: These studs only need to be snug, not tight. Over tightening could damage the case.

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Step 37 Turn the crawl box case over and temporarily install it on the front 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. DO NOT FORCE THESE PARTS TOGETHER.

Step 36 Install the other (4) studs in the same way as the first.

Step 38 Once 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 39Remove the crawl box case.

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Step 42 Reinstall the crawl box case back on the front dual case adapter as shown.

Step 41 Install the supplied gasket as shown.

Note: Do NOT use gasket sealer here. This is a dry fit gasket.

Step 43 Install the counter gear assembly snap ring.

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

Step 40 Clean the gasket surface with brake cleaner and a cloth.

Note: Double check entire crawl box for cleanliness as well.

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Step 46 Simply SNUG these (2) bolts for now. Not much more than finger tight.

Step 45 Start the (2) supplied (M10X1.25X40mm) bolts.

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

Step 44Install 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 47 Turn the crawl box case assembly over.

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Step 49 Torque the (2) bolts you installed in Step 45 to 29 ft. lbs.

Step 48Install 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.

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Tech Tip 50B This picture shows the SINGLE alignment mark on the rear dual case adapter. This mark can be positioned on any of the degree marks on the front dual case adapter. This mark can also be aligned halfway between the degree marks (5° increments) for an even wider range of positions if desired.

Tech Tip 50A To help orient the front dual case adapter with the rear dual case adapter there are alignment marks cast into each component. This picture shows the alignment marks on the front dual case adapter. They are in 10° Increments to accommodate a wide range of customer needs.

30° 20°10° 10°

20°30°

0°

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Step 51 Place the rear dual case adapter on the work bench as shown.

Step 53Apply a thin coat of Permatex® Gear Oil RTV Gasket Maker as shown.

Installing the Transfer Case Adapter

Step 52 Clean the area around the bolt holes with a good quality degreaser such a Brake Clean.

Tech Tip 53 Apply gasket maker in the area between the red circles.

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Step 54 Place the crawl box case assembly on the work bench, turn the rear dual case adapter over and position it on the front dual case adapter making sure the marks are aligned as shown in the next picture.

Step 55Alignment 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 needs. See Tech Tip 50A and 50B. Rotating or “Clocking” as we call it, can give greater clearance between the rear transfer case and the ground.

Step 56 Insure that the rear dual case adapter and the front dual case adapter are going together evenly. This is a very snug fit. If you attempt to push these two parts together using excessive force, damage could result.

0°

0°

Tech Tip 56 This shows the rear dual case adapter and the front dual case adapter properly fitted together and the clocking marks aligned.

Note: You may choose different marks.

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Step 57 Once the rear dual case adapter is properly positioned, turn the assembly over and insure that the holes align. There should be 6 holes that align properly. It may be necessary to rotate the adapter slightly to get the holes exactly aligned.

Step 58 Apply Blue Permatex® Threadlocker to the threads of the short allen head bolts.

Tech Tip 57A The bolts used in the next step are the (6) Allen Head bolts supplied in the kit. One of the 6 bolts is shorter than the rest. The short bolt is to be installed in the hole shown in the next picture.

Tech Tip 57B The shorter bolt is to be installed in one of these two holes depending on which hole aligns with the front dual case hole.

Shorter

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Step 59 Install the short bolt in the hole shown here. Just finger tight for now.

Step 60 Install the (5) longer bolts in the same way as the short bolt.

Step 61 Using a torque wrench and an 8mm allen socket, tighten these bolts in an increasingly tighter criss-cross pattern until 29 ft. lbs. is reached.

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Step 63 Install the stud in one of the (6) holes in the rear transfer case.

Step 65 Install the remaining (5) studs in the same way.

Note: Remember, just SNUG is enough.

Step 64 Snug the stud in place using the double nut method. See Step 35 to see double nut method instructions.

Step 62 Apply Blue Permatex® Threadlocker to the short threaded end of a supplied stud.

Coupling the Two Transfer Cases Together

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Step 67 Apply a good quality wheel bearing grease to the rear transfer case input shaft as shown.

Step 69 Be sure the two components are coming together evenly.

Step 68 Begin putting the two transfer cases together by aligning the studs and the input shaft.

Note: Be careful not to damage the input shaft seal.

Step 66 Position the supplied gasket on the studs. Gasket sealer is NOT needed on this gasket.

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Step 70 Continue bringing the two components together until they come completely together. There is no need for a lot of force here. It should come together easily. If it does not, pull the components back apart and figure out what is wrong.

Step 71 Once you are sure the two components will come together completely, slide the components back apart about 1/2” and install the (6) supplied flat washers, lock washers and nuts.

Note: Pulling the components back apart allows space to install the nuts.

Step 73Install the detent ball in the front dual case adapter as shown.

Step 72 Tighten the nuts in an increasingly tighter criss-cross pattern until an estimated 29 ft. lbs. is reached.

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Step 75 Install the detent plug and tighten it.

Step 74 Install the detent spring.

Step 77Add a good quality GL-5 SAE 75-90 Gear Lube in this hole (or through the shifter cavity) until it runs out of the check and fill hole.

CAUTION: Unlike some other crawl boxes on the market, this one is an isolated unit. It does not share fluid with the rear transfer case. Therefore it is critical that the crawl box be filled with gear lube before being put into service. It does not matter when it is filled, either before or after it is installed in the vehicle, as long as it is filled.

Step 76 Install the supplied drain plug in the front dual case adaptor and tighten it.

Note: Be sure plug has the supplied washer/gasket on in it.

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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

Tech Tip 78 This hole in the top of the crawl box should not be left open. Originally, it was occupied by a 4WD indicator switch. This switch could be reinstalled and left electrically disconnected or you could plug it with a plug similar to what is shown here. Either approach will work as long as it is NOT left open.

Step 78 Then install and tighten the supplied check/fill plug.

Note: Be sure the plug has the supplied gasket/washer on it.

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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 01-14-15© Copyright 2016 Low Range Off-Road, LC       All Rights