Does the average driver need the ability to crawl?

Hey y'all,

A few questions from a noob here. I'm looking to buy a 2001-2004 Tacoma and found one for sale locally. The seller says it has a Marlin Crawler transmission which is "geared for crawling only in 1st and 4-low gears". I'm not a crawler, but I do get out into the backcountry and some rough roads. My driving is pretty tame - I just want the clearance and rugged tires to get into the backroads and do some truck camping and backpacking. This rig looks to be what I want (big tires, good clearance, full size bed), but I just am not familiar with the Marlin transmission. I don't want to end up with an overly specialized rig since my needs are pretty general. My questions are: 1) is this crawler transmission overkill for me? 2) will this really affect me for "normal" on-road driving? 3) should I keep looking for something that is closer to stock? and 4) will I be offending the sensibilities of the crawler community if I don't crawl it?

Thanks!

 

better to have it and not use it than to not have it ! once you have it you"ll always want it ! makes no difference on vehicle street wear and tear GET IT ?????

 

Hello Tadow, thank you for this thread!

As @old55guy says, the nice thing about the Marlin Crawler is that it has a one-to-one (1.00:1) High Range gear ratio so when you're on an easy trail or in the city/highway, torque goes in and out of the Crawler at the same rate and other than an extra ~50 pounds, the truck doesn't know it is there.

This is also useful if your wheeling friends do not have low gearing, because you can disengage the Marlin Crawler and be able to keep up with them on easy trails or wide open stretches between obstacles.

Coming from someone who has wheeled with low gearing, there is no reason not to have this option. Because I've experienced the benefits, not having low gearing in my Tacoma when I first got it was extremely nerve racking. Exactly because the truck was brand-new, I wanted low gearing so as to not risk damage to the drivetrain and body panels. Low gearing brings an incredible piece of mind from the huge gains in vehicle control, both climbing and descending, and safety from having a longer duration of reaction time to avoid mistakes/damage.

Consider the following stock V6 automatic 3rd gen example:

With our 4.70:1 TacoBox, your transfer case ratio becomes 12.08:1 (both units shifted into low: 4.70 x 2.57), and final drive becomes 169.98:1 (3.60 transmission * 4.70 TacoBox * 2.57 T/C * 3.909 R&P = 169.98).

If we assume whatever obstacle you're climbing requires 15% peak engine torque, which for the 3.5L is only 39.75 lb-ft which is obtainable at idle speed, then theoretically we'll have 6,756.73 TQ at each tire. (39.75 TQ * 169.98 final drive ratio = 6756.73) (Note: Factory front axles won't break until at least 50K TQ, and factory rear axles probably close to 70K, so even through 6,700 TQ seems extreme, it's well within normal operating range.)

Now, without the TacoBox, your final drive ratio returns to the stock 36.17:1 (3.6 trans * 2.57 t/c * 3.909 R&P = 36.16607), and in order to achieve this same torque at each tire we need 4.7-times more engine output (since we've removed the 4.70:1 TacoBox) which is 39.75 TQ * 4.70 = 186.825 lb-ft engine torque. (Verify: 186.825 TQ * 36.16607 final drive = 6756.73).

Finally, using K&N filter's 3.5L baseline dyno chart, 186.825 TQ doesn't come in until just after 4,000 RPM.

So here we see the TacoBox accomplishes at a smooth, quiet, efficient, and easy to control idle speed what otherwise would require FOUR THOUSAND RPM for the same TQ output.

Try this exercise: Sit in your truck in Park/Neutral and rev your engine to 4,000 RPM and hold it there for a few moments. Now go back to an idle. That's a big difference when you experience it this way and this is precisely how I go wheeling with my Tacoma, where I never have to rev over ~ 1,200 RPM, even with 40" tires aired down to 4 PSI, no matter how steep the obstacle is.

This is why we no longer have to rev the snot out of the engine just to climb up something. Of course there are factors of traction and sometimes you have to backup and gun it, but in this situation I _always_ try crawling the obstacle first ... because I have the option.

What happens when you compound the issue by pulling a trailer, or are fully loaded with a week's worth of food and supplies, or you have very large tires deflated for better traction and are climbing straight up a wall. To drive the point home: With a TacoBox, the engine only needs to work 4.7-times less for the same result, or conversely, if your truck loaded weighs 6,000 lbs and can idle in gear up a mild grade, then provided sufficient traction it could drag 3.7-times this amount behind it such as a 22,200 lb trailer while at the exact same smooth and quiet idle. (Truck + load = 1 truck + 3.7 x truck = 4.7 total load)

This is why we don't have to rev the engine to get power, and if you don't have to increase engine speed then you aren't increasing tire speed, and you aren't bouncing, and you don't have impact shock loads that break axles, and you're not constantly grabbing brakes and stalling, and you don't have the risk of catching traction at 4K RPM suddenly flying off your intended line now at a high rate of speed with incredibly limited reaction time to stop all that built-up inertia.

In fact the TacoBox is so good, most of the time I run around with the t/case in High and TacoBox in Low, which already is nearly 20% better than a brand new Jeep Wrangler Rubicon yet I can still get up to 40 MPH in 6th gear without needing to shift out. It's extremely versatile and entirely optional to engage or go back to factory gearing at the flip of a lever.

The low gearing of the TacoBox provides tremendous control, traction, and performance to your off-road experience, and because we can go slow we've got the added benefit of not digging holes and kicking rocks out from under our tires thereby having a safer experience for the spotter and rigs behind us, and preserving trails and roads for others to enjoy

Regards,
BigMike

ps. I got interrupted many times while typing this so sorry I hope I didn't get too far off track. I enjoy these discussions and this was a nice break, now back to work I go!

edit: fixed spelling & improved readability

 

What is the tacobox? Is it stock or aftermarket. New to Toyota. Just picked up a 19 TRDOR.

 

@Tadow! I am sorry. In my excitement to respond to the title, I entirely skipped your questions!

We probably can't answer all your concerns until we figure out what the seller is trying to indicate. As far as transmissions are concerned, we do rebuild manual transmissions. Assuming this is a 3.4L 6cyl, while we offer a lower first gear ratio (5.15:1), this isn't applicable for the type R150F found in a Tacoma. In the case of a 4cyl, we only offer the standard 3.95:1 first gear found in the W59. So to say it is "geared for crawling only in 1st" transmission gear is incorrect.

So either the seller...

1. Has a transmission rebuilt by us, as stated, which itself does not generate the ability to Crawl (defined as 80:1 final drive or better), so he/she is bluffing or trying to pad the price by claiming the truck can Crawl when it cannot, or

2. Regardless of the transmission, perhaps he meant to also say it has Dual Marlin Crawler Cases which therefore would make it a Rock Crawler.

I have a suspicion the transfer case is 100% stock and this truck currently has no capability to Crawl. That's where I would start: Ask the seller if the transfer case is stock and go from there.

Nevertheless, if it does have our dual transfer case setup, you don't have to become a Crawler because it's up to you how you want to use or not use it. We have thousands of customers who are hunters who don't want to rev their engine to maneuver around while out hunting, and appreciate how much quieter and slower their truck can move so they don't scare away wildlife while parking. These are usually nearly bone stock trucks with our Crawl Box added to make life off-road much easier.

Extra notes:

A Heavy Duty Marlin Crawler rebuilt 1st gen Tacoma manual transmission retails for ~$1,100 which might add $500 or so to the value of the truck, depending on miles. If it also has our Heavy Duty clutch, which would be awesome, that retails for around $300 and would add maybe $150? to the value depending on condition.

• 6cyl Tacoma HD Transmission: https://www.marlincrawler.com/transmission/rebuilt-complete/r150f, HD Clutch: https://www.marlincrawler.com/clutch/heavy-duty/clutch-tacoma/1995-04-6cyl-1200-lb-clutch-kit
• 4cyl Tacoma HD Transmission: https://www.marlincrawler.com/transmission/rebuilt-complete/w59, HD Clutch: https://www.marlincrawler.com/clutch/heavy-duty/clutch-tacoma/1995-04-4cyl-1200-lb-clutch-kit

If it is a Marlin Crawler Dual Transfer Case with factory chain drive t/case, then this is a TacoBox which retails for $1800-$2200 depending on options, but there is more such as driveline mods (~$300), interior shift handle and all installation labor (~$1000), and maybe also an optional/custom Dual t/case mount crossmember ($500?). Due to the demand, if I was the seller I'd add no less than $2,500 atop normal selling price regardless of how many miles the TacoBox has.

• TacoBox for 3.4L manual setup: https://www.marlincrawler.com/trans...oma-1st-gen/dual-case-tacobox-34-liter-5vz-fe
• TacoBox for 2.7L manual setup: https://www.marlincrawler.com/trans...oma-1st-gen/dual-case-tacobox-27-liter-3rz-fe

Best of luck with the purchase!!

Regards,
BigMike

 

1. No!
2. No!
3. No!
4. No!

I think you'll find the "crawler community" not easily offended.

 

Hello richtor! You've got a fantastic first name Sir Also, nice score on the new OR. Would it happen to be one of those pictured in your avatar?

The TacoBox was created in 2001 and is the first Dual Case setup for 1995+ Tacoma/4Runner/others, and manufactured by us/Marlin Crawler here in Fresno, California. Our website: https://www.marlincrawler.com

What it does is it adds a second low range to your truck. This significantly increases the gear reduction thereby greatly improving off-road capability, mostly concerning traction and control. While it is not the first mod a new Tacoma owner does, we do have customers coming from the older Minitruck generation who are experienced and appreciate low gearing so much they install it early on (such as myself). It is a pricey upgrade, however. When it's all said and done, it will cost around $2,500 to $3,500 depending on your capability. But what you get is entirely priceless and greatly extends the life of all drive train components from saving fuel and wear and tear on your engine, to lower loads on your transmission, to less heat under the hood, to saving your engine/trans mounts, greatly increases engine compression braking resulting in far safer & controlled descents plus prolonged brake pad life, less bouncing resulting in extended suspension life, no more doing burn-outs resulting in increased tire life, and so on.

We have a full description on our website, so it would be best to review this info here: https://www.marlincrawler.com/trans...ma-2nd-gen/dual-case-tacobox-35-liter-2gr-fks

TL;DR Here is a summary of the many advantages the TacoBox provides:



Hey sweet background image! haha

Regards,
BigMike

 

@richtor Here are a couple videos to demonstrate the TacoBox in action:

https://www.youtube.com/watch?v=WrRBbh6-eGU

https://www.youtube.com/watch?v=wFPCd9oVx7g

https://www.youtube.com/watch?v=mW2RB_VyIyI

Also, don't worry about the degree at which these Tacomas are built. The takeaway is that there is an alternative to being a hot headed and dangerous throttle jockey: The TacoBox.

While the majority of our customers run tires in the 33" to 37" range, as mentioned above hunters and other stock use vehicles also receive all of the benefits from that summary chart in my previous post.

Have fun with your new Tacoma, I sure love mine!!

https://www.youtube.com/watch?v=wV1J1S41wcE

Regards,
BigMike

 

Sorry guys, I've been working all day on RCLT HD and have been using this thread as a break to clear my mind between tasks. So my focus is greatly tied up elsewhere (with this project) and I didn't even think about the perfect video to illustrate all of my statements...

Ok, this is a pass of me driving the same climb as the last video posted above, but skip to the 2:12 min mark for clips of vehicles without low gearing and notice what they must do.

In all examples the driver must apply a great deal of throttle to get enough torque to the wheels as discussed above. There literally is no other way to tackle this climb for these drivers. Go too slow and the torque converter stalls (autos) or engine dies (manual).

I could do as they do: I could disengage my TacoBox reverting the truck back to factory gearing, and have the same shortage of torque requiring me to rev the engine and go fast. But screw that. I like my truck too much to abuse it this way so I choose to first try and Crawl it, and the 1% of the time that fails, then revert to momentum wheeling. Having the choice of how to take on an obstacle is priceless.

In fact it is much worse for me because I have much larger tires which are heavier and have a much longer lever arm in the wrong direction consuming torque... yet my truck is calmly idling @ 650 RPM with zero throttle input. As far as the ECU knows I am just idling through a parking lot. This is the beauty and simplicity of gear multiplication in action!

Skip to the 2 min 12 second mark and let me know what you think

https://www.youtube.com/watch?v=seFE4P3_TTo

Regards,
BigMike

 

Thanks Mike,

Right now I’m more interested in what it will do stock, as far as low range and crawl factors compared to other 4wd trucks and Jeep’s. Which is why I tuned in to this thread.

 

Thank you all for the info and thoughts, I appreciate the responses. I finally looked at the truck in person and sadly it was not in good shape - needed a new front end, needed lots of climate control parts, had a lot of oil leaking from somewhere, and a few other things. So, the search continues for now. But I'll looking out for a TacoBox. Cheers!

 

Thanks for the update, bummer it wasn't "the one". The real question on everyone's mind is did it have Dual Cases?

 

Awesome 3rd gen, my best friend has that exact model. The color is what makes it so beautiful, of course.

Also great choice in getting a Toyota. I think you'll definitely be pleased over the many years to come. Also thank you for jumping into this thread of such deep a topic as Rock Crawling and gear ratios. Perhaps a few years down the road if you decide to take it to the next level, definitely consider drastically reducing your vehicle's final drive ratio for incredible gains in off-road control, performance, and safety. I'm not looking to sell you on a TacoBox today, but I'd like to point out some misconceptions between being geared for Rock Crawling and what Toyota refers to as "Crawl Control" that could be helpful further down the road.

Crawl Control

The term "crawling" just means to crawl, as Marlin would say and which is our mascot, "to go slow like a turtle". While Toyota's Crawl Control accomplishes this, it should not be confused with the ability to Rock Crawl. If this were the case then any vehicle with an automatic, such as my wife's Yaris, would be a Rock Crawler. All you'd have to do is ride the brakes and feather the throttle and you're crawling, and that is precisely what Crawl Control does as it is a four wheel independent brake-and-release system, and for this reason it is only available on Automatic models that have the ability to stall the truck without killing the engine.

Crawl Control is certainly better than no precision four-wheeled traction control of all Toyota pickups in the past, but it is only meant for temporary use that cannot be used continuously on any serious trail due to the brakes overheating. This limitation only becomes worse when combined with oversized tires with heavier components (armor, winch, tent...) and recovery gear.

Another way to look at it is that Crawl Control places the entire drivetrain in a constant state of load, including the engine, that you wouldn't want to do for 16 hours on the trail weekend after weekend. The engine must work to load up the torque converter to generate enough torque to overcome the brakes, and then the brakes must drag and create enough friction to be able to continuously prevent excessive wheel speed under load. Crawl Control's symbiotic relationship of excessive power output combined with excessive brake force input that results in a controlled crawl speed is what generates heat from all parts experiencing high loads in unison.

To illustrate with a random YT video, notice how even unloaded and on level ground, Crawl Control jerks the truck back and forth and the engine and brakes are modulated to fight in harmony. The loud popping sound results from bleeding off extremely high brake line pressure through the ABS system (full stopping force!). I can understand all the hype surrounding Crawl Control. At least trucks have the ability to do these things from the factory. But this is not a substitute for Rock Crawling.

https://www.youtube.com/watch?v=lIOuSAjy2CE

A final point is that the larger the load the harder Crawl Control must work. For best off-road performance you're going to want larger than factory A/T or M/T tires that are deflated to 15 PSI or less for both improved ground clearance and traction. A larger tire requires more torque to rotate, deflating tires increases rolling resistance, and multiplied by 4 (tires). We then add bumpers, sliders, winch, accessories, tent, camping gear, spare parts, and so on... and then ask the system to carry all that weight up a steep climb whilst continually dragging the brakes and fighting gravity... And we can imagine the extra effort demanded from the engine, in an endless battle with the brakes, making clear that Crawl Control was never meant for Rock Crawling, case in point, in that the greater the truck is modified for Rock Crawling, the greater the drawbacks of Crawl Control are exasperated to the point of system overload.


Rock Crawling

We like to define a Rock Crawler as having a final drive ratio of 80:1 or higher. The ideal ratio, what we refer to as "The Ultimate", is around 120:1 for automatics and 220:1 for manuals which is achieved with our TacoBox Supreme which adds an additional 4.70:1 reduction to your transfer case. From the factory, most Toyota trucks are in the 30:1 to 40:1 range. Because factory trucks lack low gearing, as discussed above the engine must output more torque to achieve the same result obtained from simply having lower gearing. Think of riding a Road Bike vs Mountain Bike up hill.. as slow as possible. This wouldn't be a problem if it wasn't for the fact that engines require increased RPM to develop torque, which means the vehicle is now moving at too fast a rate of speed for precise vehicle control and henceforth you're no longer crawling. Take brakes out of the equation and Crawl Control loses it's meaning.

Here is an example of my Tacoma from 2017 with a TacoBox Supreme gear ratio of 235:1, which is 5.4 times lower geared than stock. Ignore for a moment how steep this is, and consider how my truck is slowly crawling without any throttle or brake input needed to maintain this slow speed. Gearing reduces load on the entire vehicle so that we don't have to simultaneously load the drivetrain and brakes. The result is a smooth, gentle, quiet, easy-going crawl speed without any stress from stop and go jerking and high line pressure and loud popping sounds of the ABS system fighting the engine.

https://www.youtube.com/watch?v=JmHoEs_c11o

The same benefits of low gearing apply when descending. If you are familiar with engine compression braking, this will be easy to understand, but to explain, consider how a gear ratio is a reduction from engine-to-tire, ie. 30:1, but a multiplication from tire-to-engine, ie. 1:30. This means that for every rotation of our tires the engine rotates 30 times. Now imagine your engine is turned off but it is still in 1st gear and connected to your tires. If gravity accelerates your truck to where your tires are rotating at 25 RPM, your engine would be rotating at 750 RPM (25 RPM * 30). Now consider the above 235:1 gear ratio. If my tires were going the same 25 RPM then my engine would be going 5,875 RPM (25 * 235). Both of these examples are within the operating range of our engines, but because an engine has pistons that compress air/fuel mixtures, multiplied by 4 or 6 depending on engine, the amount of energy required to rotate an engine at a steady 5,875 RPM compared to 750 RPM without any other input (ie. fuel) is astronomically more.

Just think about our 3.5L engine resting on an engine stand... Arnold Schwarzenegger in his prime couldn't even rotate the flex plate for even 1 RPM!


(couldn't find a back shot of our 2GR-FKS, so here is a smaller 2.5L 4GR. )

For this reason, provided the vehicle has traction, gravity is outmatched by the energy required to accelerate the engine when combined with our TacoBox Supreme, and the engine speed doesn't even deflect from idle. This is true with autos or manuals, and below is an exaggerated (580:1 Triple case) demonstration of a manual transmission to drive the point home.

https://www.youtube.com/watch?v=UrPERJ6qx8g

How is this possible without any brakes? Why doesn't it turn into a run-away freight train? Think about this: My truck weighs about 4,900 pounds yet the engine only "sees" or experiences the load of 8 pounds (4900 lbs / 580 = 8.4). Yes. Eight pounds. And thus, indifferent to the constant extreme brake drag of Crawl Control, is the power of gear multiplication.

Finally, to contrast with the final Crawl Control paragraph, a gear reduction reduces required input by its gear ratio, so where ever a gear reduction is inserted (or increased), the load/stress/heatsoak of all components upstream are reduced. For the example of our 4.70:1 TacoBox, this means the transmission has 4.7-times less stress, potential to run 4.7-times cooler, torque converter/clutch have to work 4.7-times less, the engine works 4.7-times less, 4.7-times less fuel required & heat generated (probably not directly correlated but I'll leave it to make the point), engine mounts experience 4.7-times less strain, and so on. Then on the flip-side, because we aren't locking up the brakes every inch of the way, all loads downstream are decreased extending life of your transfer case, drive line carrier bearing and yokes, ring & pinion, axle shafts, CV joints, wheel bearings, leaf springs, IFS control arms & bushings, front knuckles & ball joints, and of course, brake shoes & pads!

Conclusion

In conclusion, by being appropriately geared for crawling rather than simulating it by dragging the brakes, my fuel economy is vastly improved and under-the-hood + brake temps vastly decreased. Overall wear and tear is greatly decreased, components last far longer. My truck could be crawling in place up against a brick wall for hours on end until it would simply run out of fuel as if it was left idling unattended in a parking lot, such as this example of my 1981 Hilux crawling in place in 2WD while the engine is idling without a care in the world made possible with a Marlin Crawler transfer case setup

https://www.youtube.com/watch?v=8mrFkpYKJ6Q

This comparison has only scratched the surface of Toyota's Crawl Control vs Marlin Crawler's TacoBox, as with the TacoBox, there is...

• No messing with switches and dials,
• No risk of computer or electrical system failure,
• No beeps and nagging warning lights,
  
• Transforms your 2-speed transfer case (1:1 High, 2.57:1 Low) into a 4-speed (1:1 High, 2.57:1, 4.70:1, and 12.08:1 Lows all independently selectable),
  • A Jeep Wrangler Rubicon only has a 1:1 and a 4:1
• Provides twice as many gears both forward (24-speeds) & reverse (4-speeds),
• Provides a Neutral t/case gear (few modern Toyotas have this),
• Provides a 2WD low range,
• Is incredibly fast and easy to engage no matter if you're in 2WD/4WD or High/Low Range or rear locker engaged/disengaged or engine on/off, key in ignition or no key at all
• No longer need the parking brake when parked on very steep grades,
• The TacoBox reduces stress, load, and heatsoak of upstream components by nearly 5-times (transmission, torque converter/clutch, engine, engine mounts),
• The TacoBox reduces stress, load, heatsoak downstream by who knows how much (not revving, not bouncing/overworking the suspension, not doing tire burnouts, not continually fighting full brake force, etc), and best of all
  
• The vehicle reverts to its 100% factory form when the TacoBox is not in use.

Cheers!

Regards,
BigMike

 

My take Craw control SUCKS ! Thanks for the learning course BIG MIKE