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Marlin Crawler's New Rock Crawling Long Travel IFS Suspension System (#RCLT)

Discussion in 'Long Travel Suspension' started by BigMike, Feb 2, 2019.

  1. Feb 2, 2019 at 11:57 AM
    #1
    BigMike

    BigMike [OP] Applied common sense Vendor

    Joined:
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    Member:
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    Vehicle:
    2016 56-speed 580:1 Triple Marlin Crawler-equipped TRD Sport
    Product Link: MarlinCrawler.com/RCLTHD
    Application: 2003+ SUV, 2005+ Tacoma
    FAQ: RCLTHD/FAQ | Q&A: RCLTHD/QA


    Update Feb 16, 2022

    Hello TW!! Hope everyone has been well! I took a hiatus from the forum for exactly one year to focus on customers, products, and my family. Things have been great here in Crawler Land!
    I just updated the thread with a post to Page 119 here :cheers:

    NEW All owners now receive exclusive access to our online installation database for 1-on-1 support if needed!

    RCLT HD has been available since last year and is thriving, now on it's Third Production Run!

    https://www.youtube.com/watch?v=F37sbkpovXQ

    https://www.youtube.com/watch?v=Ymd2c4oSqyo

    https://www.youtube.com/watch?v=EeNkfxceKb4

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    --
    --

    Update Feb 9, 2020
    We have a lot to get updated!

    RCLT HD placed Top 10 in the King Of the Hammers competition under a V8-powered 4Runner, becoming the first Toyota IFS to run both desert & rock crawling trail sections at the most abusive single-day off-road race on the planet!

    https://www.youtube.com/watch?v=fD4SdVZwoDI

    --

    THREAD UPDATES
    Click here to receive update notifications to this thread
    --

    May 6, 2019
    Race Report from RCLT HD V1 Prototype used in the 2019 King Of The Hammers (reply #262)

    [​IMG]

    May 17, 2019
    RCLT HD V2 Prototype is completed and installed!! (reply #281)

    [​IMG]

    July 29, 2019
    RCLT HD is now up on our Store Website collecting demand for the initial kits!
    --> https://www.marlincrawler.com/suspension/rclt/rclt-hd <--


    ========================================
    ========================================


    Hello TW!! It is my extreme pleasure to announce the next step forward in off-roading the Toyota Independent Front Suspension System with the all new Marlin Crawler Rock Crawling Long Travel IFS!

    Marlin Crawler's New "RCLT": Rock Crawling Long Travel IFS Kit
    The First Rock Crawling-specific Long Travel Suspension System!!

    I'd like to create this thread as a home for posting updates in preparation of production slated for this summer. This journey has taken nearly two years and I'd like to provide an overview first.

    Background

    I have been an avid off-roader of front solid/live axle Toyota trucks, 4Runners, and Land Cruisers since the 1980s. My live axle truck is a 1981 shortbed Toyota Hilux pickup with a Marlin Crawler 511:1 Triple Transfer Case setup and 37" tires. I am highly experienced with it and trucks like it on trails of all types and terrain.

    In 2016 I purchased my first IFS truck, the then all-new 3rd generation Toyota Tacoma (build thread), and stepped into a new world. After owning the Tacoma for a year, I did my first IFS modification which was an Upper Control Arm (UCA) kit to properly lift the truck 2.5-inches and fit 33" tires (285/70R17, 32.7") with part of each body mount frame bracket cut off. I referred to this as "Stage I" and here is a pic of it with the World Famous 1980 Crawler Truck:

    [​IMG]

    In this picture I had an aftermarket UCA, factory LCA, Fox 2.0 Shocks, and factory steering, as well as a Marlin Crawler Dual Case TacoBox resulting in a 235:1 Crawl Ratio. For what I am used to these tires were small, but combined with the TacoBox it was a nice introduction to learning how to Rock Crawl with IFS. Here I am in a slow & controlled descent without brakes, Flat Iron Mesa Trail, Moab, UT, May 5, 2017

    [​IMG]

    Can I fit ___-tires?

    One of the most common IFS questions I see is, "Can I fit X-tires without trimming?". A UCA kit enables more lift but even with just 32.7" tires I had to cut off part of my body mount frame brackets behind both tires in order to turn without tire-to-frame interference. For me this was an acceptable modification but there are reasons why one wouldn't want to cut their frame...
    • You don't plan on keeping the truck
    • The truck is being leased
    • You aren't sure or only want to test the setup
    • You're looking to transfer parts to a different truck without having to go through the process again
    • You want to keep your front mud flaps
    • You want to run tires larger than 33"
    If we're already having to modify the frame to fit 32.7" tires, how much more cutting will be needed to fit 35s, 37s, ...or dare I say, 40s? ;)

    The Rock Crawler's entry-level Tire Size

    In Marlin Crawler's opinion and by extension that of the Rock Crawling industry, if you want to be taken serious as a Rock Crawler then you should have 35" or taller tires. While it's true you could take hard lines on the Rubicon with 33s and a lot of rock stacking, you simply cannot run many trails at the Hammers (SoCal) with 33s due to a lack of ground clearance, traction, and inability to stack rocks due to how steep the trails are.

    So I set my sights on improving the Toyota IFS specifically for use with tires no smaller than 35", and as you'll see this has a trickle-down benefit for smaller setups as well. :thumbsup:

    Early development

    In early 2017 while my truck was 9 months old and still rock'n factory 265/65R17 (30.6") tires, I was working on something that had never been done before which was designing an IFS kit specifically for the Rock Crawler. Based on decades of Rock Crawling experience, I initially came up with six ideas to improve existing Long Travel (LT) designs. Here is an early quote from my build thread:

    My local wheel'n buddies thought I was joking when I told them I won't be doing a Solid Axle Swap to the Tacoma and even more laughter when I said I will make an IFS comparable to a mild SAS. Within the first year of wheel'n the new truck I was on my way to improving late-model Toyota Rock Crawling ability when I completed what I called "Stage II".

    Using the first of my specific Rock Crawling designs, I modified an existing +2 LT kit creating a one-of-a-kind IFS setup unlike any before it. Here is my Tacoma during the Summer of 2017 on 37x12.50x17 BFG KRAWLER T/A tires undergoing R&D for what would become the First RCLT:

    [​IMG]

    What's impressive is that I have fitted 37" tires with the only body mount trimming being what I originally did to fit 285/70R17. Going from 32.7" to 37" is a huge jump yet the new tires only just lightly rubbed the body mounts at full steering lock... How... How was this possible....?

    A new Rock Crawling-specific IFS system is born

    For almost two decades the aftermarket has had 4WD Long Travel IFS kits that improve stability & suspension travel, yet none of these can Rock Crawl 35" tires with a full range of steering without requiring frame modifications for late model Toyotas.

    The Marlin Crawler RCLT solves this problem, and I present to you our first proof of concept that you can go from 33s + UCA straight to 37s without any additional body mount modifications :eek:

    [​IMG]

    I only planned to run this first prototype for a few months but the project was put on hold last winter requiring a full reboot. What came out of this was my full-on no-holds-barred Rock Crawling IFS kit, pouring years of experience and trail testing into what I believe has become a truly remarkable setup!
     
    Last edited: May 13, 2022
  2. Feb 2, 2019 at 11:57 AM
    #2
    BigMike

    BigMike [OP] Applied common sense Vendor

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    We concluded above that a 35" tire is the minimum size to be taken serious as a Rock Crawler, and straight away we have an issue that factory steering is only reliable with up to 33" tires due to inner tie rods failing and steering racks eventually going out when combined with 35" or larger tires. To remedy this, last spring I came up with the Marlin Crawler MarRack, which I believe is the strongest factory-style street-legal steering rack upgrade for late model Toyota IFS systems.

    The MarRack is the first HD Steering Upgrade that integrates with LT in a way never done before

    The MarRack has already been discussed in my build thread, but what I've intentionally not disclosed until now is that the MarRack enables a new & improved steering geometry with the following Rock Crawling advantages:
    • Increased steering power (rack ---> trail)
    • Decreased stress from objects on the trail (rack <--- trail)
    • And most importantly it enables the knuckles to be pushed forward more than anything done before for Rock Crawling with IFS!
    ...We are talking about a Rock Crawling IFS System that can be unbolted and the truck restored 100% back to factory suspension using simple hand tools.

    ....We are talking about Rock Crawling IFS approach angles closer to or even on par with Solid Axle Swaps.

    ......We are talking about an all-new IFS System that can Rock Crawl alongside Solid Axle Swaps!

    Welcome to the BRAND NEW WORLD of Toyota IFS Rock Crawling

    Welcome to the birth of the Toyota Rock Crawling IFS industry, brought to you by the founder of the Rock Crawling industry, Marlin Crawler. We will be sharing updates on our way to producing Rock Crawling Long Travel Kits (RCLT) this Summer, so please click here to enable thread notifications and enjoy the ride with us!

    The facts are simple: (1) No Long Travel IFS Kit can Rock Crawl 35" tires without modifications to the frame, and therefore (2) No Long Travel IFS Kit is designed for Rock Crawling.

    The goals of the new Marlin Crawler Rock Crawling Long Travel System:

    1. To install 35" tires without any frame modifications [​IMG]
    2. To improve approach angle closer to or even on par with Solid Axle Conversions [​IMG]
    3. To take full advantage of the Heavy Duty MarRack Steering System [​IMG]
    4. To carve a new path away from existing Long Travel kits never designed for Rock Crawling [​IMG]

    How has Marlin Crawler accomplished this for Rock Crawling?

    1. By moving the knuckle forward from its factory location for IFS approach angles never done before [​IMG]
    2. By increasing ground clearance of the traditional lower control arm design to a level never done before [​IMG]
    3. By having the strongest street-legal factory-style steering system integrated with the suspension in a way never done before [​IMG]

    All three issues, approach angle, ground clearance, and steering strength, are a serious handicap to the IFS off-roader and all three are solved with the new Marlin Crawler RCLT!

    Here is my Tacoma collecting important IFS test data on 40" tires and a 580:1 Triple Transfer Case Setup, Bald Mtn Trail, June 1, 2018

    [​IMG]
     
    supralee, Icon_Adrian, Nopro and 15 others like this.
  3. Feb 2, 2019 at 11:58 AM
    #3
    BigMike

    BigMike [OP] Applied common sense Vendor

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    Initial RCLT FAQ:

    What Kits will be offered starting this summer?

    (1) Marlin Crawler RCLT Standard Kit (+1 RC +2 LT)


    Who is this for?
    -- Every IFS owner who enjoys 33s but has been considering moving up to 35s, which can now be done without any additional trimming to your body mounts
    -- Those already on 35s who have wanted to run 37s but haven't due to strength and body mount clearance
    -- Daily drivers who don't go off-road but would like to install 33s with zero trimming or modifications to... anything!

    What will be included?
    -- 2 x Upper Control Arms
    -- 2 x Lower Control Arms
    -- Associated parts for installation
    -- Optional Upgrades: MarRack with weld-on Steering Arm Adapters, UCA & LCA Frame Mount and Knuckle Gusseting

    Detailed specs
    • "+1 RC": This industry-first nomenclature is the Rock Crawling (RC) capability!!
      • Knuckle moved forward 1-inch (25.4mm)
        • Compatible with/same specs/measurements as existing Long Travel coilovers (Fox, King, Radflo, ICON...)
        • We are a Radflo distributor and will offer their shocks with our RCLT kits
      • Rock Crawling approach angle closer to that of a Solid Axle Swap (SAS)
      • Unparalleled ground clearance of any traditional IFS kit on the market, details below
      • Re-uses factory Knuckle
      • Factory vertical single-shear ball joint orientation, using stainless steel uniballs top & bottom
      • Compatible with Factory Steering
      • Optional: Compatible with our Marlin Crawler Heavy Duty MarRack Steering System
        • Requires cutting two holes and adding one weld to your sub frame assembly
        • Requires welding MarRack R & L steering arm adapters to your factory knuckles
        • Does not modify or interfere with factory rack mounts, ie. the MarRack may be removed and factory rack + unmodified knuckles reinstalled
      • Compatible with Factory CV Joints

    • "+2 LT": Industry-standard Long Travel nomenclature, +2.00" (50.8mm) longer per side, overall +4" (101.6mm) width increase
      • Compatible with factory fenders

    • Targeted tire size: 35" to 37"
      • Whatever tire size you have now, you can move up +2" larger diameter without any additional modifications to your body mounts
      • 33" tires clear unmodified body mounts and cab seams with room to spare
      • 35" tires, depending on wheel offset and tire width, may rub on unmodified original body mount at full steering lock (cutting/grinding not required)
      • 37" tires will require the same amount of body mount clearance as if you were fitting 33" tires with a UCA kit
    • Entire system may be removed and vehicle restored 100% back to factory suspension using ordinary hand tools

    (2) Marlin Crawler RCLT Heavy Duty Kit (+2 RC +2.75 LT HD)

    Who is this for?
    -- The avid off-roader already running 35s and would like to move to 37s, which can now be done without any additional trimming to your body mounts and zero fear of steering failure
    -- The hardcore Rock Crawler considering SAS but doesn't want to permanently cut up his or her truck or lose IFS handling & drivability
    -- The hardcore Rock Crawler who wants to run 39s or 40s + IFS! Axle companies have had shafts strong enough for 40" tires and it's about dang time someone made an IFS kit that can do the same!

    What will be included?
    -- 2 x Upper Control Arms
    -- 2 x Lower Control Arms
    -- 2 x HD Knuckles
    -- 1 x MarRack with "Mini-Marlink" HD Tie Rods
    -- Associated parts for installation
    -- Optional Upgrades: UCA & LCA Frame Mount Gusseting

    Detailed specs
    • "+2 RC": New Rock Crawling (RC) capability!!
      • Knuckle moved forward 2-inches (50.8mm)
        • Requires LT coilover assembly with both upper & lower heim joint mounts
          • Compatible with/same specs/measurements as existing Long Travel coilovers so long as they have both upper and lower heims
          • We are a Radflo distributor and will offer their shocks with upper & lower heims for our RCLT kits
        • Depending on tire size, may require trimming of existing aftermarket bumpers as well as inner fenderwell sheet metal under battery tray (driver side) and windshield washer reservoir (passenger side)
      • Rock Crawling approach angle comparable to mild Solid Axle Swaps (SAS)
      • Unparalleled ground clearance of any traditional IFS kit on the market, details below
      • NOT compatible with Factory Steering
      • Requires our Marlin Crawler Heavy Duty MarRack Steering System
        • Fully realize the raw power of the MarRack that makes anything greater than "+1 RC" possible!
        • Requires cutting two holes and adding one weld to your sub frame assembly
        • Does not modify or interfere with factory rack mounts, ie. the MarRack may be removed and original rack + IFS components reinstalled
      • RCV Ultimate Axle shafts strongly recommended

    • "+2.75 LT": +2.75" (69.85mm) longer per side, overall +5.5" (139.7mm) width increase
      • Why +2.75? This is based on my own experience of 19,000+ miles testing with 37" and 40" tires, as well as data obtained from a Class 4600 King Of The Hammers (KOH) Race Truck build (see below)
      • Intended goal: To achieve up to 3-inches more suspension travel than traditional +2 LT kits while avoiding the need for Fiberglass fenders. Trimming of factory fender and/or installing larger flares will be required
      • Why not just go all out? Because this is not a desert race kit, this is for Rock Crawling, and Toyota is making these trucks so huge these days it's a challenge as-is getting them up and down tight, technical trails.
        If you've Rock Crawled long enough, you'll know that you can get stuck by being too wide, too
      • It's the sweet spot between "...2-inch just isn't enough" and "...3.5-inch is too wide"

    • "HD": Heavy Duty Knuckles
      • Maximum Strength and reliability for Rock Crawling
      • Horizontal double-shear stainless-steel uniball design top & bottom
      • Double-shear tie rod heim joint design for greater strength, safety, and range of motion than factory ball joint TRE
      • Additional down-travel may easily be added by improved CVs or location of differential
      • Knuckle designed to reduce rate of camber change
        • Maintains a more perpendicular tire contact with the ground for better traction over very large rocks
        • Reduces bump steer to improve on-road drivability with large Rock Crawling tires
      • Compatible with factory ABS/speed sensors

    • Targeted tire size: 37" to 40"
      • Whatever tire size you have now, you can move up +4" larger diameter without any additional modifications to your body mounts
      • 35" tires clear unmodified body mounts and cab seams by approximately 3 inches :eek:
      • 37" tires, depending on wheel offset and tire width, may rub on unmodified original body mount at full steering lock (cutting/grinding not required)
      • 40" tires will require the same amount of body mount clearance as if you were fitting 36" tires on an ordinary Long Travel suspension kit
        • RCV guarantees their Ultimate Axle Shafts with up to 40" tires
        • We have over 15,000 miles of testing the MarRack and RCV shafts with 40" tires!
        • Have fun!!!!
    • Entire system may be removed and vehicle restored 100% back to factory suspension and steering using ordinary hand tools

    Application?

    Initially 4/6/8cyl 2002+ 4Runner, Lexus GX470, FJ Cruiser, and 2005+ Tacoma.

    Availability?

    Late Spring or Summer release

    Pricing?

    Will be released as we approach summer.

    What testing has been done?

    I have tested an early prototype from which our RCLT Standard Kit is based on combined with our MarRack & both 37" and 40" tires, having done the Rubicon 6 times and highway driven from California to wheeling events in Texas, Colorado, and Utah. Currently testing our first RCLT HD prototype in a 4600 Class Competition-built 4.7-liter 8cyl 4th gen 4Runner that will be racing in next week's King Of The Hammers event in not only the Wednesday "Every Man Challenge" but ALSO the main Ulta4/Unlimited race!! :eek: (the goal Friday is to finish before time expires)

    What if I'm not a Rock Crawler?

    Rock Crawling is fun and popular with many events around the country. You don't have to be a Rock Crawler: Daily drivers who just want to run slightly larger than stock tires may now do so without having to trim anything. RCLT finally puts an end to the age old question of "Will it fit without trimming".

    "RCLT" forges our own distinguishable path and avoids confusion with existing LT kits that do require body and frame modifications.

    Isn't Rock Crawling dangerous?

    We created the Rock Crawling industry 25 yrs ago for older Hilux trucks/4Runners and now have many highly reliable upgrades for these trucks. As such our customers rarely ask, "is this dangerous?", because it is only as dangerous as you make it.

    But because the IFS world only has transfer case solutions for Rock Crawling, short of doing a SAS its been stuck with horrible ground clearance, horrible approach angle, horrible steering strength, and horrible knuckle strength. That is until now. The Marlin Crawler RCLT solves all of these and for the first time ever you can go Rock Crawling without the fear of IFS holding you up or letting you down!

    Is the concept of RCLT unique to Marlin Crawler?

    To illustrate the uniqueness and amazing ability of RCLT, we are especially proud to announce that the Marlin Crawler Rock Crawling Long Travel IFS System is Patent Pending!!

    Marlin Czajkowski created the Rock Crawling industry 25 yrs ago and we are protecting his incredible legacy as we push Rock Crawling deeper into the 21st century!

    [​IMG]
     
    Last edited: Feb 2, 2019
  4. Feb 2, 2019 at 11:58 AM
    #4
    BigMike

    BigMike [OP] Applied common sense Vendor

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    First prototype RCLT HD Kit

    Next I'd like to get into the details surrounding our first prototype RCLT HD that we finished last month for a King Of The Hammers race truck!

    Back in May of last year I was contacted by a gentleman named Charles from Alabama who was building a 4Runner for the Every Man Challenge (Class 4600) of the 2019 King Of The Hammers competition. Charles heard about our MarRack and knew he'd need it if the truck was to survive KOH. He already had sponsorship for a +3.5 LT kit and was hoping we would sponsor his steering system.

    A problem in sponsoring only the steering is that the MarRack has a certain feature that I've been careful to not disclose which is how it enables the front axle to be pushed forward more than ever thought possible without causing component interference. Based on measurements, the MarRack has the ability to replace stock 265 tires with 39" tires in one shot without ANY body mount or A-pillar cab seam interference. :eek: I am serious. While this is true for the MarRack, unfortunately it isn't possible yet due to limitations of CV joint technology. Further, there isn't a bolt-on LT kit on the planet that can do this either so the MarRack was ahead of its time.

    In creating the MarRack I specifically wanted it to be wider than factory for the explicit Rock Crawling advantage of longer than factory steering arms to...
    • Reduce steering wheel effort from the driver, and
    • Reduce loads acting back onto the rack from objects on the trail
    Therefore, to truly take advantage of the MarRack you'll want a Long Travel kit that moves the knuckle waaay forward -- doesn't exist -- and you can't just slap the MarRack in and drive away: It requires either (1) factory knuckle steering arm extensions -- doesn't exist -- or even better, (2) new knuckles that have longer-than-stock steering arms -- doesn't exist either. :smack:

    Three events took place simultaneously which kickstarted the Marlin Crawler RCLT:
    • I was building the first MarRack prototype
    • My first prototype LT project required a full reboot, and
    • Charles needed a steering + IFS system worthy of the most difficult Rock Crawling competition in the World

    Charles didn't just need the MarRack; He needed a complete Heavy Duty Rock Crawling IFS System unlike anything available that maximizes the advantages of the MarRack.

    Charles' 4.7L V8 4Runner shows up to Rock Crawling Headquarters, November 2018. It has fiberglass fenders due to the +3.5 LT mentioned above which I accepted as a one-off sample.

    [​IMG]

    Design Considerations of the first Marlin Crawler RCLT HD Prototype Kit

    Having Rock Crawled the Tacoma with both Dual and Triple Transfer Cases, I've had plenty of time to ponder what can be done to improve existing LT designs for Rock Crawling. The main criteria included...

    1. Stronger steering
    2. Increased approach angle
    3. Increased ground clearance
    4. Increased articulation


    Knowing I needed custom knuckles to maximize the MarRack, the world was my oyster to develop an IFS system specifically tailored for Rock Crawling. Here is what I ended up with...

    1. Formed, boxed, and internally gusseted UCA, LCA, Knuckle
    2. Horizontal double-shear upper and lower ball joint design
    3. Double-shear steering TRE design
    4. Tremendous Ground Clearance
    5. Excellent Suspension Travel
    6. Knuckle designed for Rock Crawling
    7. V-groove LCA with smooth underbelly
    8. Extra wide LCA trailing arm for accessories


    Due to immense pressure from both time constraints and Class 4600 rules, a few features did not make it into this prototype which will be present in the next. Until then, I present to you truly the First Rock Crawling Long Travel Suspension Kit!

    The Marlin Crawler RCLT HD Prototype

    [​IMG]
     
  5. Feb 2, 2019 at 11:58 AM
    #5
    BigMike

    BigMike [OP] Applied common sense Vendor

    Joined:
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    Formed, boxed, and internally gusseted UCA, LCA, Knuckle

    The Lower Control Arm features six 3/16" steel plates arranged perpendicular to the ground that run the full length of the arm. All six plus lower and two uppers must fail in order for the arm to bend. The lower shock mount features an extra thick 1/4" single shear and pair of 3/16" double shear creating a triple shear shock mount rather than the typical LT 3/16" double shear shock mount design. I've also designed an extra wide trailing arm for compatibility with different limit straps, bump stops, and bypass shock mounting considerations. While strength is the main concern, an important center V-Groove helps limits weight (discussed below).

    The Upper Control Arm, I used an extra thick 1/4" internal gusset mounted parallel to focus on axial torque loads and impact strength for head-on trail objects. This gusset connects the front bushing to the rear half of the trailing arm, providing extra strength when you accidentally catch a rock on the trail that rips the steering wheel out of your hands.

    The Knuckle has four 3/16" steel plates arranged perpendicular to the tire providing strength when sliding laterally into a ledge or rock.

    All components are designed with double-shear horizontal ball joints for maximum strength, reliability, and range of travel.

    [​IMG]

    Double-shear steering TRE design

    I used extra thick 1/4" plate steel top and bottom to provide a double-shear steering arm. Due to the tremendous challenge of fitting the oversized MarRack under the Toyota V8, I incorporated steering adjustability into this prototype not knowing where the rack would be placed. This is our second MarRack install and I've figured out a way to standardize it which I couldn't say last year. The prototype MarRack in my Tacoma will be coming out for new modifications bringing this kit one step closer to production.

    Excellent Suspension Travel

    To (1) avoid requiring fiberglass fenders and (2) limit difficulty of being too wide for technical Rock Crawling, I've designed the production RCLT HD to meet in the middle of popular LT ranges at +2.75". Because articulation is important for Rock Crawling, the goal will be a +2.75 LT kit with 3" more travel than +2 kits, and our horizontal ball joints will enable travel very close to the best 4WD +3.5 LT kits without the negatives of being too wide for technical trails!

    Improved Knuckle Geometry

    Because RCLT HD is designed to run up to 40" tires where a truck is lifted to the point of a more unstable alignment through the full range of travel, we've designed better geometry for Rock Crawling by enabling a longer period of perpendicular tire contact for improved traction over very large rocks. This was one of the first drawbacks of IFS I noticed compared to my years of Rock Crawling solid front axles.

    [​IMG]

    Phenomenal Ground Clearance

    Ground Clearance is very important for Rock Crawling and in my short experience with IFS it has definitely been an issue. While IFS has more clearance at center, clearance under each axle shaft is faaar worse than solid axles. For example, from the factory the Tacoma has up to 5" of lost ground clearance under each axle whereas the venerable 8" Toyota live axle only experiences a ground clearance loss of 15/16" (more than 5-times better!). What sucks is that aftermarket LT kits make it worse with some I've measured being up to 6-inches of lost ground clearance under each axle shaft. :thud:

    Consider the following comparison of axle shaft (red) to ground clearance (green). We have this awesome IFS platform and yet horrible LCA ground clearance designs

    [​IMG]

    I've never liked this about IFS and my current arms hang down so low that from only six trips through the Rubicon they are scraped to hell with deep gouges. If the question is, "Why do current LT arms go down-then-out?", the answer is, "They were never designed for Rock Crawling."

    The RCLT design incorporates a center V-Groove to nestle the axle shaft nearly in-line with the control arm. I am happy to report that this first RCLT prototype has as little as 11/16" of lost ground clearance under each shaft which is a 36% improvement over SAS and something like 700% better than existing LT kits :conf:

    Did someone order GROUND CLEARANCE? :D

    [​IMG]

    I especially love how the axle disappears into the control arm at full droop

    [​IMG]

    Side note: A Class 4600 rule change during development required strap placement changes and we were testing different lengths here. These photos show beyond designed drop at where the inner CV joint binds at 30-degrees (already 5-degrees more than almost all LT kits in existence). Our next knuckle will allow a diff drop for even more downtravel
     
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  6. Feb 2, 2019 at 11:58 AM
    #6
    BigMike

    BigMike [OP] Applied common sense Vendor

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    Ok! Let's see what this Ground Clearance equates to in the real world!

    [​IMG]

    [​IMG]

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    [​IMG]

    Love that overkill MarRack steering! :cool:

    [​IMG]
     
  7. Feb 2, 2019 at 11:59 AM
    #7
    BigMike

    BigMike [OP] Applied common sense Vendor

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    These pictures of the 4Runner are on 275/65R18 tires that measure 31.5-inches. Here it is next to my Tacoma on 40x13.50x17 that measure 39.5"

    [​IMG]

    [​IMG]

    Inset Lower Shock Mount Design

    Improved ground clearance arms have been done before, but I haven't seen a bolt-on LT kit with improved ground clearance LCA + inset axle shaft + inset lower shock mount. What I've done is raised the LCA so much that a standard height LT shock bolts in with the goal of not requiring a longer-than-normal LT shock. So if you currently already have 8" shocks, then you can reuse them with all our kits (HD kit requires top & bottom shock heim mounts).

    Look at this phenomenal ground clearance advantage...

    4Runner + RCLT with 275/65R18 (31.5" actual) tires VS my Tacoma with 40" (39.5" actual) tires + typical down-then-out LCA horrible for Rock Crawling (look how scratched it is!)

    31.5" tires have 1/4" MORE GROUND CLEARANCE than 39.5" tires...

    ...No wonder I've been dragging my stupid LCAs all over the place!!

    [​IMG]
     
  8. Feb 2, 2019 at 11:59 AM
    #8
    BigMike

    BigMike [OP] Applied common sense Vendor

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    Here come some random pics from the day the truck left our shop

    [​IMG]

    [​IMG]

    [​IMG]
     
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  9. Feb 2, 2019 at 11:59 AM
    #9
    BigMike

    BigMike [OP] Applied common sense Vendor

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  10. Feb 2, 2019 at 11:59 AM
    #10
    BigMike

    BigMike [OP] Applied common sense Vendor

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    Increased Approach Angle

    The RCLT isn't just another random 4WD LT kit: It is a Rock Crawling LT Kit and the very first of its kind.

    Here is the rig at its next stop with new 315/70R17 Cooper Discoverer SST Pro tires fitted (measure 34.5" / 87.6cm)...

    [​IMG]

    ...and here is the tire turned to where it is the closest to the body mount. This is roughly 3.5-inches of clearance between 34-1/2" tires and factory unmodified body mount.

    :eek: :eek: :eek: :eek: :eek: :eek:

    [​IMG]

    And finally, the question I've been dying to ask...

    If I told you the below truck has a Solid Axle Swap, would you believe me?

    [​IMG]

    #RCLT #PatentPending
     
    Last edited: Feb 2, 2019
  11. Feb 2, 2019 at 11:59 AM
    #11
    BigMike

    BigMike [OP] Applied common sense Vendor

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    [​IMG]

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    [​IMG]

    Here is when I last saw the truck, January 17. From left to right: Matt (RST), Wyatt (owner, RST), Yours truly, and Robert from Otwell Welding and Fabrication.

    [​IMG]

    And here is an awesome message to Marlin (left) who personally delivered the 4Runner to Robert at Otwell Welding and Fabrication. :wave:

    [​IMG]
     
  12. Feb 2, 2019 at 11:59 AM
    #12
    BigMike

    BigMike [OP] Applied common sense Vendor

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    And finally, I can't close out the beginning of this thread without seeing this awesome KOH rig through to it's beautiful completion!

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
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  13. Feb 2, 2019 at 12:00 PM
    #13
    BigMike

    BigMike [OP] Applied common sense Vendor

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    Look at this, is this really a 4WD IFS setup? Look how far forward those tires are. I LOVE IT!

    [​IMG]

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    I don't know what else to say. These images more than speak for themselves :cheers:

    Happy to answer any questions about the new future for Rock Crawling IFS! Next I'll be building a second prototype RCLT HD for my Tacoma (later this month) and our first prototype RCLT Standard for a 2nd gen Tacoma (next month).

    Thank you Charles for this opportunity and for putting up with all the unreal roadblocks and hurdles I had to overcome to make this a reality!

    The 4Runner 4600 Class King Of The Hammers build may be followed via the following links:
    MC - board.marlincrawler.com/index.php?topic=103102
    IG - instagram.com/steelcityracing4x4/
    FB - Pirate - pirate4x4.com/forum/toyota-truck-4runner/2660392-steel-city-racing-...
    T4R - MUD - forum.ih8mud.com/threads/steel-city-racing-king-of-the-hammers-...

    Looking forward to watching this thread grow into a resource for all things Rock Crawling IFS!

    Regards,
    BigMike
    https://www.marlincrawler.com


    [​IMG]
     
    Last edited: Feb 2, 2019
  14. Feb 2, 2019 at 12:05 PM
    #14
    zippsub9

    zippsub9 Well-Known Member

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    Shit bolted onto other shit, and junk.
    I think I just pee’d my pants a little...
     
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  15. Feb 2, 2019 at 12:07 PM
    #15
    whitedlite

    whitedlite Well-Known Member

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    Hitting me right where it hurts.... in the wallet :spending:
     
  16. Feb 2, 2019 at 12:22 PM
    #16
    Masshole_And_His_Taco

    Masshole_And_His_Taco RIP Rick

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    Totally been waiting to hear when the MarRack was going to be released... But a complete IFS setup? I'm in. Been trying to save for a TC kit, but this is worlds better! Sub'd for pricing and production announcements!
     
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  17. Feb 2, 2019 at 12:35 PM
    #17
    HolyHandGrenade

    HolyHandGrenade NOOB

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    Is the MarRack going to work with standard travel IFS, or only with your kits?

    I’m doing 37s now, was planning to wait on the MarRack.

    If I can’t use it, I guess I need to explore other options.

    The new kits look great.
     
    Last edited: Feb 2, 2019
  18. Feb 2, 2019 at 12:38 PM
    #18
    Anchovy

    Anchovy Rule #1: Never take me seriously

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    I was going to save for a cap but now you have me second guessing that... but some questions... for those that daily drive their trucks, how would it affect on-road performance? And each kit comes with the MarRack and everything needed to install it and the kit? And I presume no shocks?

    Edit: and will this LT kit also be capable of Baja style off-roading without issue?
     
    Last edited: Feb 2, 2019
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  19. Feb 2, 2019 at 2:14 PM
    #19
    Boundlesstaco

    Boundlesstaco Well-Known Member

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    Wishlisted
     
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  20. Feb 2, 2019 at 3:09 PM
    #20
    Facts Only

    Facts Only Well-Known Member

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