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

I followed him. He didn't follow me back, lol.

 

LOL

I'm just lookin at that (lack of) clearance between the tire and spindle. And the CV boots that look like they're beer cans that have been stepped on.

 

Yeah everything is super close. I have about 1mm between my disc rotor and the spindle. They are so close that it looks like they are touching. So far no problems.

 

You'll know the moment your wheel bearings are getting a little tired. I'd call that a feature. 26.2% more likely to identify a failing wheel bearing 81% sooner.

 

63.7% of all statistics are complete bullshit

 

Hello Tacoma1192 and thanks for the questions,

While limiting up travel may be dumb, it certainly is not for the majority of truck owners. Tac05 is right: At what point does one limit his or her up travel? For example, I could go back to factory coilovers to gain tremendous up travel, maybe to the point the 40s contact my hood. But I chose not to do this much trimming and instead only trimmed 1/2" beyond the maximum compression of my long travel coilovers' compressed ability.

On that note and to your point, I am not even sure what a "long travel" coilover is. In the Toyota aftermarket industry I assume the design of a LT coilover was originally developed by Total Chaos and as far as I can tell the entire industry has adopted the phrase. I got my first LT coilover in July '17 through All-Pro who instructed I get an 8" stroke and sold me Fox p/n 880-02-953. When I installed these, I was surprised to find they had only about 7-3/4", later confirmed by Fox's catalog to be 7.67". When I switched to Radflo, I ordered, "the closest 2.5in coilover to 8in" which they said would be 7.75". Those coilovers are still on my truck today. Since then, I sent custom measurements to Radflo for a true 8" coilover which they now manufacture for us, p/n 6CT-001-5(R/A), which has an extended length of 24.5-inch, compressed length of 16.5", which ended up somehow being about an inch shorter than whatever they sent me in the first place. So the coilovers that have been on my truck since 2019 are ~1in longer and with ~.25in less compression than what we recommend to customers.

So to your comment, I trusted All-Pro's history of long travel experience when they told me I need an 8-inch shock, yet, I find on my setup that the in-board CV joints bind before my coilovers reach their full extension. The same holds true on the +3.50" RCLT HD setup I'm currently prototyping which has increased down-travel ability. Knowing that the Radflo we recommend with our kit is about 1" shorter than whatever is on my truck, I felt that's a good safe measurement for customers that also gains a bit more up-travel than my setup. So I could switch to say a 16" compressed length coilover (with 7.5" travel) which would give me 1.5" more up-travel at the coilover, probably +1.75 to 2" at the hub, and then, to your point, I'd surely need to clearance more.

So perhaps the 16.5" collapsed length of the Radflos we recommend is longer than other "LT" coilovers, which limits how much trimming is needed, but we have many customers using Fox, Icon, ADS, King, ORI, etc. so I wouldn't be quick to blame that.

If you are referring to our LCA's inverted design, I did take this into consideration by insetting the lower eyelet into the arm, which is a feature included in our patent. My goal was to keep the shock eyelet in the same spot while gaining a ludicrous amount of ground clearance under it.

In reference to our inverted LCA design and lower shock mount, please consider the following...

This is my old setup based on a custom +2" All-Pro LCA:



This is a +2" TC I rescued on the Rubicon:



This is a production +2.75" RCLT HD (photo courtesy @lostinthewoodst4r):



And finally from my rig about a year ago, production +2.75" RCLT HD with recycled MiniMarlink from a 2019 prototype:



As you can see the lower eyelets are all in the same relative area of the outer CV bell. This was a big focus of mine to keep it as close to my previous LT LCA as possible. Way back on Reply #7 I listed this as a main feature of RCLT HD whereby the ground clearance gained beneath the lower shock bolt equals the ground clearance gain of going from stock to 40" tires. This, is ludicrous.



A customer out of Mississippi had the following to say about this (source on IG):

So if you were expecting our LCA to gobble up multiple inches of shock stroke leading to premature bottoming out resulting in less up-travel and therefore less clearancing needed, then that is not the case, or at the least, a very minor difference.

I get this a lot, I'm still hanging on to the philosophy we use on our @marlincrawler IG account whereby we only follow very specific accounts (out of 29K followers we only follow 11!). Following others is a nice thing, not only for the camaraderie but also it's free advertising since often it'll say, "This account also followed by so-and-so" ...so maybe I should just start following everyone.

Thank you. Precision strength

Good eyes! This is my solution to torn bellows that I am testing for Christian at RCV During assembly, RCV lays each assembly on a flat table prior to banding their paper-thin orange boots in place, which causes excessive and repetitive stretching to the bellows every time there is any misalignment of the CVs. My solution is to immediately cut off their bands and install smooth hose clamps (McMaster 5574K21) fitted nearly 2" closer to the outboard joint which OVER-NIGHT prevents tearing to the bellows. RCV is now going to incorporate this design in tandem with their upcoming improved & much stronger boots (THANK YOU FINALLY RCV!!!! So sick of these retarded orange boots.)

One of my employees' inner bellow tearing:



Four boots on my rig tearing at an inner bellow:





On these last two you can see I switched to the McMaster hose clamps but I didn't(!!) reposition the location of the clamp relative to the inner shaft.





This one is from a customer with an absolutely beautiful Quicksand 3rd gen on 40s who I just met last weekend at the Tacomapowered/4Runnerpowered meet-up in Roseville, CA. The rig hasn't even gone wheeling yet!! Can't wait for the new stronger boots RCV is working on!!



All of these are tearing at the concaved or inner portion of the bellow. Unless you're telling me that we are all whacking Junebugs at 70 MPH in this exact location, this is entirely caused by the boot being stretched and pulled apart.

Silicone is good with heat and abrasion but not so good at constant stretching. For this reason, I came up with the idea to pre-maturely relax the boot, yes, by scrunching it beer can style, and here is the improved design which is reclamped about 1" closer to the outer CV than how RCV ships them:



And finally, here is my current setup where I've swapped in longer +3.50" inner shafts and am now testing +2" compressed design (relative to the boot's natural resting or relaxed position):



And here they are in action last month in Moab, from the same trip El Taco Diablo quoted:



So far I've been testing stepped on beer can boots since October, accumulating 7,522 miles without a single torn boot! Prior to this, I had 47,692 miles on my RCVs (same inner & outers!) and have gone through so many boots which has been a huge moly grease mess. In total I have over 55,000 miles on the same CVs and I think have only replaced ONE boot due to actual damage from the trail. (Some stick or something poked a hole, Dusy/Ershim, July 2020.) So I've had really good luck with boots, just these orange RCV boots are a complete defect from the factory and they must be losing money-hand-over fist replacing them.

In closing here come some recent pics from my 5,108 mile round-trip back-to-back Moab excursions while prototyping 3 new & never-before-done concepts. The journey of making IFS something to be proud of instead of the decades of junk you've all had to live with has been a lot of hard work and a really fun learning experience!!













Regards,
BigMike

 

That is interesting. The 8" ORIs I am running say they are 23.2” Extended and 15.825" collapsed giving 7.375" of travel, but the CVs would still bind at full bump and droop.

You have details on these boot modifications? I don't want any torn boots.

I was half teasing. I have like 2 posts, not expecting much followers... yet.

 

Comparing your LCA angle to mine at ride height. You have more negative angle. This may explain why I am getting better articulation, since you are closer to full droop at ride height and have less up travel due to the 40's. You do, however, have much more ground clearance. Especially with my 1/4" skids.

 

There's an additional "top-out" spacer I believe 7/8" thick. Pretty sure that its not just All-Pro that has this additional spacer inside a "Long Travel" coil-over that's offered for the 2nd and 3rd Gen Tacomas. That spacer it just the fool proof way that prevents inner cv to half shaft bind for the average consumer who doesn't have the means, or knowledge to properly setup limit straps.

 

Im really curious on the travel numbers they expect on 35s with no fenderwell or firewall modifications. Even more what are the expected numbers with 37s and 40 without cutting. One of the main factors that they say makes this the only rock crawling kit, is that "No Long Travel IFS Kit can Rock Crawl 35" tires without modifying the cab A-pillar mount... ". But if your cutting into the fenderwell instead of a cab mount or firewall to reach your advertised travel number, i dont see any merit to that statement. Just on page 127, @Tac05 , was just saying how he needs to relocate his battery, that was not advertised on the marlin website and it seems like a necessary modification to achieve thier stated travel numbers. The sherpa guys have told us personally thier numbers and how they cant modify thier inner fenders because of class racing rules.

If your going to make big claims to reinventing the wheel, you need to be transparent about its down falls and the required work to achieve the expected outcome.

I think the rclt kit is a really good setup and i hope it pushes other manufacturers to step up thier game instead of copying one another. Jd fab is already talking about a horizontal upper balljoint and custom spindle to work with thier existing lowers and 934cv axles.

 

Customer: "Can I fit 40s without trimming?"

Marlin:

 

@BigMike what type of steel are you using for these kits?

 

This is the point I made back here https://www.tacomaworld.com/threads...sion-system-rclt.591033/page-75#post-25969341
I was still waiting for the kit to ship, but already had all the other parts. At the time it wasn't clear to me that I'd have to cut anything besides the cab mount. I was confused why Marlin was advertising not having to cut the cab mount when it is way easier to do than modify the inner fenders and wheel wells. The initial response was that the extra trimming was common sense, but I argued that it clearly wasn't for someone new to the industry. I believe they updated their marketing to be more clear on what is required, but they cant tell you the travel numbers you will get without cutting because your tire size and wheel offset is an unknown variable.

 

But they can tell you the potential travel numbers with an asterisk stating that that's best case scenario like all the other LT manufacturers.

 

Hello WarFab! Dude I was sooo close to crashing your event last month! My original plan was to head north from Easter Jeep to a friends house in SLC, stay there for 4 days, then to west CO to run trails with you guys, and then go back to Moab for TLCA's Cruise Moab, but during this time we brought on 2 new employees so I just couldn't stay away for the full 24 day journey (I left for Moab 4/8, drove back 4/17, then left again for Moab 4/25 & returned 5/2).

I did get to crash the Tacomapowered/4Runnerpowered meet in NorCal last weekend which was fun! Did my first-ever "Walking The Crawler" up an RTI ramp

https://www.youtube.com/watch?v=817AKVhDgzE

Ohhhhhhhh wow you've gotta be correct, I never think of this because I cut mine off long ago Prior to that, I did run 40s for 1 trip to Moab and 4 trips through the Rubicon with the factory bump stop bracket and prototype v2 (the dark-gray painted version with red 'RCLT HD' stickers) and even still I had to trim a lot to clear 40s. This required much more trimming than what I had already cleared when I had 37s.

Not sure why this is being lost in translation with others, but 40" tires are freak'n huge. As posted on page 119, 40" tires absolutely dwarf 37s. We both know IFS + 40 is not easy and requires a hell of a lot more than just

40x13.5R17 left vs 37x12.50R15 right

It was my first time on Metal Masher and I was running it solo with a co-pilot (@airkewled!) who only having just met gave me some great spotting. So we had no other vehicle to help in case of emergency plus neither of us knew what line to try, but no matter what I tried I kept getting hung on my passenger side rear link frame hanger. We probably tried a good 20 mins. The frame hanger ground clearance has been a reoccurring issue with my rear 3-link that I've wanted to improve for sometime. The main links are the only RST parts remaining and those puppies are 47.25" long for the mains and 50" for the upper!! So I am working with TacoRunner (4WU) to design a setup using shorter links for a lower profile frame mount setup.

More on my rear setup, I finally threw the old RST panhard setup that kept ripping off the frame in the trash and designed my own with an integrated crossmember the old setup lacked. RST's panhard had a 14° downward slope at ride height which I've now replaced with a 1° downward slope. High speed handing is night-and-day better, especially quick lane changes on the highway. Finally, now that the front end is +7" over stock I'm planning to replace the rear housing with a wider Diamond and refresh the RuffStuff brackets

Man... Those ORIs are amazing. You really went with a good choice there. Plus, their overall diameter appears to be less than a coil spring, so you have a zero chance of encountering any knuckle-to-coil interference at full droop which is great. Thank you for the extended length measurement. This is very good to know which means we don't need the full 8" travel shock I've spec'd to Radflo. You've got the best of both worlds: Shorter, unnecessary overall length plus shorter compressed length. This is how you're achieving 14.5" at the hub whereas my coilovers that are nearly 26" extended were only getting about 12.5" at the hub with my old +2.75" arms. So there's 2" of lost up-travel on my Tacoma right there that I didn't have to worry about while fitting 40s.

Yes, just order that SKU from McMaster. Here is a direct link: https://www.mcmaster.com/5574K21/ You'll only need 2 (or 4 to replace both ends), but unfortunately they only come in a pack of 10. Maybe just use that link for reference and pickup some locally. I recommend the smooth band type so they don't cut into the boot. The only real instructions would be to mark where the boots are before you cut off RCV's bands, and then scrunch the boot closer to the CV by at least 1". I'm currently testing 2" and so far so good. Nice thing is clamps are adjustable and can be tightened after the boots have broken in to prevent grease from leaking at the clamp.

Hey MonkeyProof thank you for this! This totally makes sense now. They probably make only a few bodies and then "limit" stroke length in this way for different applications, etc. Good to know thanks!

Hello CGoss, nice to meet you. I suppose the answer to this goes back to what I discussed above regarding what collapsed length coilovers are used. Thirty-fives are really easy to install with RCLT HD and is possible to cycle using typical LT coilovers without fenderwell or firewall modifications, verified on Steel City Racing's 2006 4Runner running prototype +3.50" RCLT HD, Icon LT coilovers, and 315/70R17 (~34.5") with custom hydro bumps using the full compression of the Icons. I don't know what the travel number is on this or Sherpa's, but with only 35s I'm certain sheetmetal trimming is not the limiting factor because fitting 35s with RCLT HD is very easy. If anything, it would be fender trimming in front of the tire which most people have to do for aftermarket front bumpers anyhow. For reference, here is Steel City Racing's tire clearance in front of the unmodified body mount frame bracket on our 1st prototype/2018:



EDIT: Here is a side-view showing tire placement. Also these are fiberglass fenders (don't know anything about them or their brand). So the region in front of the tires were trimmed to fit the bumper, which provided sufficient room for the tire.

Taco05 definitely helped right my midset on this which I am grateful for. Coming from the live axle world, no one ever talks about trimming this or that. You put your head down, build your rig, and go wheeling. But in the late-model IFS world it's "bolt-on or death" and it wouldn't surprise me if more than 90% of TacomaWorld members don't own a grinder or welder. As a result, marketing in this space is entirely different and has been both a challenge and a blessing for me.

How awesome it is to see posts like this. Truly validates the journey we are on. Forty-inch tires now part of the IFS conversation... A literal dream come true.

Hello Dayman Karate and thank you for the question. We use hot-rolled ASTM-A36 plate and 1018 billet steels. Neither of these contain Cr or Mo, so in case you were wondering I made the decision to use 1/4" ASTM-A36 instead of 3/16" chromoly because (1) it's stronger [1/4" non cr-mo plate is stronger and more dent resistant than 3/16" cr-mo plate] and (2) this is designed around rock crawling which doesn't need to be lightweight (in fact having more weight down low is a benefit to off-camber wheeling). Thinking back, thank God we went this route because sourcing chromoly plate right now is a complete nightmare and unsurprisingly prices are completely through the roof.

Okay, I have now spent waaay too much time on the forum and need to get back to work. Have a nice weekend everyone and safe travels

Regards,
BigMike

 

The ORIs were a PAIN to wrestle in there, well the remote reservoirs were, but I am glad I went that route. Being able to change ride height and spring rate without swapping coils is amazing in itself.

Thank you fr the info on the boots. I looked at mine last night and one is already torn! I've driven the truck twice since getting her home. Damn.

Have you noticed any issues with the marrack boot? Mine popped off on the in board side. Same side as the RCV boot tear.

 

Is RCV replacing these boots for you? I sent them an email, no response. Then looked at their website. It says the boots are not covered by warranty. These boots tore on one drive. Paying for a replacement is rough, but it sounds like you didnt have to pay for yours?

 

I got someone on the phone at RCV, they are going to send me new boots, but black ones instead of the silicone orange. He says they are stronger.

 

Update on this, I am working with Radflo on redesigning the coilovers they make to spec for us (source 1, no comp. adj. & source 2, with comp. adj.). Would you mind please measuring how much shock shaft is exposed at your current full droop, assuming you've got the limit straps set just before the RCVs begin binding. No hurry and thank you very much

Alex sent me many pics and it looked awesome out there, definitely wanna check those trails out

This is so simple it's genius. I never thought of this and looking around online it's all over the place I love how very little roll steer the rear has so it would be great to keep those links long.

In order to maintain my anti squat with a new steeper upward angle on the main links, which I last calculated to be 109% anti-squat/+7% roll axis/27" roll cen height (I do like how the truck climbs with all this anti squat and don't mind having a less active rear end under throttle since I rarely abuse the skinny pedal / never Send It) (It's been a while and will double-check measurements tonight to keep the calculator updated), I'll have to raise the upper link's frame mount higher (not much room for that) or lower it at the axle (but then to maintain separation from the lower links I'll need to remount those even lower which they're already mounted beneath the housing...) Hmmmm This is great, got another project to work on this summer! Gaining this ground clearance will be a HUGE upgrade for the truck.

You have NO IDEA how jealous I am of this.

Negative, since 2018 I've never had a boot come off. Would this be your left-hand / driver side boot? If so, remember we supply a replacement boot clamp for that side so maybe it either wasn't fitted all the way or the clamp hadn't been tightened.

Negative, we keep purchasing new boots each time. There was one incident where my shafts were clicking pretty bad (these RCVs seem to click for nearly everyone) so I sent them in for warranty and they came back with new boots on both ends which was nice. We do get a discount because we are a distributor, but companies like RCV and BudBuilt, where they're shipping heavy items made in the USA with very low profit margin (believe me: we know), we are only getting about 5% off and by the time we pay freight for large orders of axles and skid plates we've broken even or in some cases especially with BudBuilt we end up losing money for every skid plate we sell which is why we just can't offer full axle shaft sets or skids from third parties on our website.

For you guys out on the Island it must feel like living in another country where you're paying import and duty taxes Even for us, we can only offer our flat-rate shipping to "the lower 48 States"... I guess that's the cost of living in one of the most beautiful places on the planet!! Ngl definitely jealous of that!

Tip on boot grease: When we replace boots ourselves, we hardly put any grease back in. I've found that just the centrifugal forces from the weight of the grease alone can cause the orange boots to tear, so having less grease residing in the bellow portion also helps the boots last longer. We still grease the joint, obviously, but we remove excess grease outside the joint.

(The old adage handed down from Marlin is to pack as much axle grease as possible to leave no room for water -- which holds true for live axle setups running felt gaskets -- but with IFS CV shafts it's a fully-sealed enclosed joint system so I don't mind having free space that may help prolong boot life, just know that if it tears in the future you'll want to get it replaced sooner than later.)

Tip on accessing the shafts: On Appendix A8 we note the very simple & quick way to get at the axle with RCLT HD, and we've come up with an even quicker way which is to not even remove the brake caliper at all (eliminates step #3). Just remove the brake line clip from the knuckle and this provides enough room to swing the knuckle in front of the axle and slide the axle out. (Link to Instructions)

Tip on removing only just the outer CV joint: RCV uses a strong inner clip at the outer joint and it can be a PITA to remove. The way we normally take these apart is to first remove the entire inner CV assembly (boot and all) and then insert the exposed axle end into a long post or pipe, and then whack that vertically/upright atop a block of wood causing the inertia of the shaft itself to rip out from the outer joint which remains stopped up top by the post.

But, since it's only the outer boot that keeps leaking, this is a method to remove only just the outer joint and is even a suggested method by RCV themselves plus other shops here in town use which is to smack the joint against a table edge as shown below.

This is one of my guys taking apart my own shaft from my Tacoma, which have probably been removed like this a half dozen times and are still powering 40s with no problems. While this isn't the best-practice method and you should use your own judgement, these are seriously strong parts that can take a lot of abuse, I have no problems doing this to my own parts, and believe-it-or-not they don't even leave a mark from where they contact the table. Alternatively you could do this to a wooden table or a metal table with HDPE top layer:

EDIT -- Wanted to add more tips for this method: Note how we bend at the knees to come down in one fluid motion with the assembly. The idea is to use the natural acceleration of the assembly mass to do most the work. If you've ever lifted one of these shoulder high you'll know what I'm referring to. Just come down with a focused force and you can get them apart first try. Here he missed the first hit and had to hit it again. Next time I have a leaking boot I'll update this with a better attempt, also with safety glasses on. I also didn't mention this but use tin-snips to remove the bands (or in our case we just unscrew the hose clamps mentioned earlier) and then scissors to cut away whatever is left from your old orange boot, wipe away excess grease, and then give it a go. The item that falls down in the video is just a glob of grease.


https://youtu.be/UeXEL7urR3w


Tip on sealing minor CV boot leaks: I use this flexible vinyl glue which works really well at sealing slits or small tears in CV boots so long as you get the cuts sealed before they turn into huge holes. The main tip is to fully degrease (I use brake spray + rag + air dry) and get a couple coatings fully dry/cured between applications. I find 3 good coatings (waiting 3ish hrs between application) works great:

$9 Loctite Vinyl Fabric & Plastic Repair Flexible Adhesive 1 oz, 1 Squeeze Tube

https://smile.amazon.com/dp/B001F7E9VI

I remember when I first got the Tacoma many of my Hilux/4Runner live axle friends told me I'll be living with "squeaky IFS" (has never squeaked) and "CV boot grease everywhere" and boy or boy were they right about the damn CV grease. I don't want to blame IFS for the grease. If RCV would just make a proper boot that lasts then we wouldn't even be having this discussion

This is good to know because we need to pick up a couple more for spares and will give those a go next

Regards,
BigMike