Regular price
Sale price
Regular price
Sold out
Unit price
Select Options

  • Overview
  • Features
  • Tech
  • Fitment
  • Common Questions

Eco-Crawler - The easiest & strongest gear box for your Toyota 4x4.

Current Eco-Crawler Lead Time is 8-10 Weeks

At Northwest Fabworks we set out to produce products our customers are as proud to own as we are to make them.  Since 2005 we have poured our passion for manufacturing into the 4x4 industry and continue to set the bar high through responsive support, unmatched quality, and manufacturing our products in house.

Initially working with the domestic transfer case market, we garnered a cult following with our Blackbox, EcoBox and Titan series product lines.  Proven to improve handling and control through selectable gear reduction, our development team set out to bring the same innovation to the much-needed Toyota market, and the Eco-Crawler was born. Existing dual Transfer case or Gearbox options for 1984 – Current VF Chain drive equipped Toyota 4x4’s are either poorly executed, or non-existent. Previous systems required sourcing old gear drive components, purchasing multiple adapters, and the end result was weak, unreliable and excessively long. 

How did we do it ?

Instead of utilizing sections of an older transfer case, the EcoCrawler kit provides a new billet aluminum housing that accepts stock VF transfer case planetaries. The housing is a direct fit to the stock transmission, and doesn’t require any shaft adapters or couplers.

How Does It Work ?

A chain drive transfer case is required to use as a "donor" for the EcoCrawler. The low range planetary unit is removed from the donor transfer case and inserted into the EcoCrawler housing. A custom NWF input shaft is installed into the vehicles transfer case. This produces an integrated connection between the EcoCrawler and the transfer case, removing the requirement for a splined coupler. Watch the video at the top of the page for a visual understanding of the process!

Quick Reference of Compatible Vehicles - Review Fitment for Details

  • Toyota Pickup
  • Toyota T100
  • Toyota Tacoma
  • Toyota Tundra
  • Toyota 4Runner
  • Toyota FJ Cruiser
  • Toyota Sequoia (Pending Fitment Data)
  • Lexus GX460
  • Lexus GX470  

What is Required :

Donor VF Chain Drive Transfer Case for Planetary Gears. - See Chart in the Fitment section in FAQ for best choice.

*Torsen Type VF Transfer Case are NOT Suitable for donor gears.

*Stock Shift Lever is required if not using NWF Trident Shifters




This product is for off road use only. The products supplied in the delivered kit are manufactured and assembled specifically for the purchased conversion type. All modifications to components that have not been approved or authorized by Northwest Fabworks (NWF) will void warranty and/or returns. NWF is not responsible for damaged components that are not included in the purchased product. NWF is not responsible for damaged NWF products caused by the failure of non-NWF parts. NWF does not cover damage caused by incorrect installation and/or assembly. NWF does not warranty products that have been used outside of their intended use. Installation of the following product may void automotive manufacturer warranty.  


Eco-Crawler Total Length

VF1, VF2, VF4




Atlas 6 and 8 bolt



Ford NP205


GM Small/Large Bore


Material Type

6061-T6 Aluminum

Gear reduction

Selectable 2.57:1 low range

Approx. Weight


Oil Capacity

~3/4 qt (varies slightly between combinations) 

Oil Type

Redline MT-90 or factory recommended chain drive oil


Utilizes the Factory Planetary Gears, Selectable 2.57:1 Low Range

6061-T6 Aluminum Billet Housing

Short - No Longer than 6.5” Overall Length – Maximum Drivetrain Clearance

Strong – 1 Piece output, no splined connection! (Excluding RF1A)

Simple – No additional adapters required! Our kits are adapters and under drives all-in-one!


Fitment Tables and Install Manual

Click Here to see fitment tables

Click Here for the VF2/VF2 Installation Manual

Have these pieces fallen out of your transfer case while opening it up?

Click Here for the Reinstallation Guide of the Shift Collar Detents

How To Fit Your Vehicle

STEP 1: Determine your Transmission bolt pattern and select which EcoCrawler Lid fits your vehicle. (Read below sections and see fitment tables at the bottom of the page)

STEP 2: Determine your Transfer Case bolt pattern and select which EcoCrawler Base fits your Transfer Case. 

Compatible Transfer Cases:

RF1A: Requires 23 Spline Input, Top Shift Required

VF1: Top Shift Required, 3VZ-FE Type

VF2: Top Shift or Electric

VF4: Top Shift or Electric

VF4 Torsen: Torsen Equipped Transfer Case, common to 4-Runner, Sequoia, GX460/70. Sequoia and GX470 must convert to top shift.

Ford NP205: Use Married Type

GM / Dodge Fig.8 Large Bore: 90mm Input Bearing

GM / Dodge Fig.8 Small Bore: 80mm Input Bearing

Atlas 6 Bolt 6 Spline: Verified by Serial Number

Atlas 6 Bolt 32 Spline: Verified by Serial Number

Atlas 8 Bolt 32 Spline Verified by Serial Number

Dana 300: Jeep Type


Atlas transfer cases require modifications to the cable shifters for proper fitment and functionality. Direct linkage shifters for the Atlas DO NOT fit with the EcoCrawler. For details, please call customer support at +1-(250)-248-6024.

STEP 3: Determine the shifting interface that you require - or if you plan to purchase the Toyota Trident Triple Shifters (only applicable to Toyota transfer cases). Read the below sections for details on these steps.


Understanding Your Vehicles Bolt Pattern (VF1, VF2, and VF4)

VF1, VF2, and VF4 refer to the bolt pattern between the output of the transmission and the input of the transfer case. Over the years, Toyota has modified and updated this pattern, making specific models and generations require different patterns for the EcoCrawler. Refer to the tables in the Fitment section to find what pattern your vehicle uses. If your data is not available from the Fitment section, please call and inquire about your vehicle at +1-(250)-248-6024.

The “Lid” of the EcoCrawler mates to the transmission, while the “Base” of the EcoCrawler mates to the transfer case. If the transfer case being used in the vehicle will not be the stock case (i.e., swapping an electric shift transfer case with a manual shift transfer case), make sure to know the year, model, and engine that the transfer case came from. This will allow you to select the correct “Base” bolt pattern if it is different from your transmission (or “Lid”) bolt pattern. See the tables below for the range of vehicles that can be used and their data.


  • EcoCrawler does not support RF1A transmissions (Lid bolt pattern), but will support 23 spline top shift RF1A transfer cases (base bolt pattern).

  • Atlas transfer cases require modifications to the cable shifters for proper fitment and functionality. Direct linkage shifters for the Atlas DO NOT fit with the EcoCrawler. For details, please call customer support at +1-(250)-248-6024.


Understanding Ball vs. Spade Shift Types

Spade and Ball shift types refer to the style of connection between the transfer case shift stick and the transfer case shift block. Vehicles with “J” shift patterns (i.e., manual transfer cases) are likely to have a Spade type connection, while One Touch transfer cases (cases that have manual shift Hi/N/Lo and push button 4X4) are likely to be a Ball type connection. This is important to know because the EcoCrawler will place it’s shift position in the same spot as the original transfer case position; allowing you to use your stock transfer case shift stick and boot. Your transfer case, however, will be at max 6.50” pushed to the rear of the vehicle, and will require a shift stick to be sourced that matches its interface. Fully electric transfer cases can use either one of the shift types depending on the stick that is being used. If you are installing the Trident Triple Shifter kit, then a spade type connection is required.


What Shift Position and Type Is Your Vehicle?

Gain access to the transfer case shift stick by removing the center console and shift boot. Remove the four M8x1.25 bolts that hold the shift stick to the transfer case or transmission (depending on position, as explained above).

If the connection between the shift stick and transfer case is circular and resembles the photo below, your vehicle is a Ball type connection.


If the connection between the shift stick and transfer case contains flats on either end and resembles the photo below, your vehicle is a Spade type connection.


When looking into the transfer case, if the shift blocks are built into the shift rail and the ring gear is visible (see photo below), than your vehicle is a Top Shift. If the shift block is a circular Ball type connection then it will not be built into the shift rail, but the ring gear will still be visible, and the shift rail will extend past the shift block.


If the shift blocks are a separate piece that is attached to the shift rail via a roll pin, there is no ring gear visible, and the shift rail does not extend past the shift block (see photo below) than your vehicle is a Forward Shift. This is also possible with a Ball type shift block.



Common Questions

Question: Does the Eco-Crawler work with my Toyota 4x4? 

Answer: If your Toyota originally had a VF (chain) type transfer case, the Eco-Crawler will work for your vehicle. Compatible vehicles:

-Toyota Pickup /w G58, R150F

-4Runner 1986-1995 /w G58, R150F. 1996+ All

-Tacoma - All years

-FJ Cruiser - All years

-Tundra (Excl. 5.7L)

-Sequoia (Excl. 5.7L)

-Lexus GX470 - All years

-Lexus GX460 - All years

-Hilux – N60 with VF Case, N70

-Surf  with VF

-Prado with VF


Question: What is a Toyota VF Transfer Case? 

Answer: The Toyota VF transfer case was the successor to the RF1A gear drive case. In the early 90s Toyota began to phase out the RF1A in favor of the VF series chain-drive in favor of cost, noise, and fuel economy. The VF transfer case has a 2.57:1 low range, both passenger and drivers side drop configurations, and additional features developed to modernize, including electric actuation, and traction control systems.

Question: I thought Gear Drive was the best for a Toyota dual case reduction box? 

Answer: In the 4x4 world of yesterday the RF1A was favored, the gear reduction section was easy to separate from the remainder of the case, lending itself well to adding additional low range sections or ‘doubling’ the cases. Additionally the RF1A was a RH drop transfer case, matching up well to the early solid front axles.

For a period the entire aftermarket was dedicated to the RF1A, it was plentiful and well supported. In 1996 however the magic ended; domestic Toyotas switched to a LH drop transfer case and front end. The RF1A no longer made sense to be used for gear reduction.

Companies entrenched in selling product related to the RF1A made attempts to discredit the VF case, it was in their favor to do so. However, the product provided to continue the use of the RF1A were multiple adapters, weak shafts, and cases prone to failure, The reality was the VF case had a strength edge, was easy to mate to the newer transmissions, but the gear reduction section did not easily separate like its predecessor. Fortunately for Toyota 4x4 owners we at NWF enjoy machining big blocks of 6061 billet!!

Question: My vehicle uses an RF transmission, can I install and EcoCrawler? 

Answer: Unfortunately the EcoCrawler line is not compatible with RF transmissions. If your vehicle comes stock with an RF1A (gear drive) transfer case, the EcoCrawler will not bolt up.


Question: Can I use an RF1A (gear drive) transfer case behind the EcoCrawler? 

Answer: Yes! as long as your transmission is not an RF (gear drive) bolt pattern, the EcoCrawler line has a gear drive transfer case option. The transfer case must be Top Shift (see fitment category for Top Shift description) and be a 23 spline input.


Question: My EcoCrawler is popping out of gear, what could be causing this? 

Answer: There are two possible causes for the EcoCrawler to pop into neutral. If it is popping out of high range, make sure that the shift rail on the EcoCrawler is not interfering with the transmission extension housing. If there are areas that are interfering, grind the area down so that the shift rail has clearance throughout it's full moving range.

If the EcoCrawler is popping out of low range and you used an electric shift transfer case as the donor, make sure that the correct Low Range Spline Connection is being used. The connection from electric shift transfer cases have a recessed tooth profile and do not allow the EcoCrawler to fully engage (see photos below). A Spline Connection from a manual shift transfer case must be sourced, or the part can be purchased from Toyota using part number 36284-35021.


Question: Should I use my vehicles original transfer case as the donor? 

Answer: While not all transfer cases can be used as donor's for the EcoCrawler internals (see fitment section for which transfer cases are usable), it is highly recommended to use your vehicles transfer case or one from the same generation and trim. Some input shafts will engage with various transmissions but they have a smaller or larger outside diameter, making the transmission seal sit incorrectly on the shaft. This will cause the  transmission to leak trans fluid from between the transmission and the EcoCrawler. To prevent this, make sure that the input shaft being installed into the EcoCrawler is the correct fit for your transmission.



Knowledge Center Articles

  • Sample Video Embed From Youtube

    Secondary Heading Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut ...

  • Shipping Timeline

    All orders are processed within XX to XX business days (excluding weekends and holidays) after receiving your order confirmation email. You will re...

  • Lorem Ipsum

    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim venia...


Our products are made to the highest standards with zero compromises on quality or materials.