Crawl Box

[Bumbo]

I have been a bit fascinated with the Marlin Crawlers website recently...

Really liking the idea of a crawl box but don't see a lot of talk around here about these things. Does anyone have, one, what is your experience with it?

Dual Case TacoBox, 4.0-liter 1GR-FE | Marlin Crawler, Inc.

Not an inexpensive modification, but really seems to take the truck to the next level. I think I would prefer this over the electronic version of crawl control we see in the 5th considering you can actually get torque multiplier benefit from the gearing... website shows an estimated 2000 ft/lb in dual low with a 206:1 ratio.

 

[fourwd1]

If you're seriously into rockcrawling dual cases is the way to go.
The earlier 4 cylinder trucks had the option of changing the t-case ratio from stock 2.28 to 4.0 or even 4.7. I installed the 4.7 in my t-case when I built my 84. It made an incredible difference. Later I added a stock 2nd t-case and ended up with a 224:1 crawl ratio. The truck's unstoppable.

 

[Bumbo]

I don't consider myself a serious rock crawler... if I was I would have probably converted the 4runner to a solid front axle or moved to a different platform by now.

I spend too much time in the desert to walk away from an IFS setup.

That said, I do have to get into the rocks on occasion and very uneven or technical terrain. I understand most issues occur (broken CV or gears) when applying too much throttle and wheel spin over obstacles.

Eventually I was thinking of doing an LT setup with even larger tires, but to better protect the trucks drive-line over these types of terrain, would a crawl box help?

Perhaps I am not getting the FULL value out of it, but even if it helped protect from a broken CV or diff gear, would it not be worth it vs a trail repair.

I'm interested in the better engine breaking, control, increasing reaction time, and low end torque so I can go slower. At least that is what I gather from the Marlin website.

 

[duffdog]

To my knowledge, nobody has invented a crawl box that works with the ATRAC system on the 4th gen. Since you can't really disable the computer, you can't disable the ATRAC entirely, which means you can't truly have a crawl box installed unless it works with all the speed sensors inside the existing transfer case. This type of engineering is beyond the abilities of the aftermarket currently, even though all you would have to do is change the planetary insert from a 2.6 ratio to a higher ratio, nobody has either attempted or marketed such a solution.

 

[Inv4drZm]

To my knowledge, nobody has invented a crawl box that works with the ATRAC system on the 4th gen. Since you can't really disable the computer, you can't disable the ATRAC entirely, which means you can't truly have a crawl box installed unless it works with all the speed sensors inside the existing transfer case. This type of engineering is beyond the abilities of the aftermarket currently, even though all you would have to do is change the planetary insert from a 2.6 ratio to a higher ratio, nobody has either attempted or marketed such a solution.

I don't see how it would change anything with ATRAC. I'm just guessing here but ATRAC could still be computed by comparing the input speed in the old tcase to the wheel speed sensors.

The reduction happens before the OEM t-case, not after, so the t-case and wheel speed sensor system should be unaltered theoretically.

 

[WhiteBoomer04]

Call Wyatt Scott at RockSolidToys.com. He installs Marlin Crawl Boxes all the time. He's putting one in my 4th gen and doing my solid axle swap too.

I have the FJ cruiser case to bolt it up to, so no problem there. The 4th gen (and possibly the 5th gen) may have problems with the stock transfer case and bolting up the crawler case that then either hits, or wont fit, with the stock gas tank.

Call Wyatt. He knows the deal.

 

[AuSeeker]

Call Wyatt Scott at RockSolidToys.com. He installs Marlin Crawl Boxes all the time. He's putting one in my 4th gen and doing my solid axle swap too.

I have the FJ cruiser case to bolt it up to, so no problem there. The 4th gen (and possibly the 5th gen) may have problems with the stock transfer case and bolting up the crawler case that then either hits, or wont fit, with the stock gas tank.

Call Wyatt. He knows the deal.

If you look on Crawler's website it states that the gas tank needs to be modified, so yes the gas tank is a clearance issue and since it really doesn't say how to modify the gas tank who knows, other than someone who has added the crawler box to a 4TH Gen what has to be done to modify the tank.

 

[Inv4drZm]

If you look on Crawler's website it states that the gas tank needs to be modified, so yes the gas tank is a clearance issue and since it really doesn't say how to modify the gas tank who knows, other than someone who has added the crawler box to a 4TH Gen what has to be done to modify the tank.

In the Tacomaworld thread I don't remember them mentioning the fuel tank issue, only the driveshaft lengthening/shortening.

Its an issue with the FJ's but they are a little shorter than us 4Runners.

I heard how they used to modify the fuel tank was to heat them up (plastic of course) and dent them out of the way, that or plastic welding a new panel in, though there was at least one instance where it leaked afterward.

We might be able to swap in the FJ fuel tank (18 gal) and have it all fit, not sure if it is much shorter than ours though.

 

[rickashay]

I have been a bit fascinated with the Marlin Crawlers website recently...

Really liking the idea of a crawl box but don't see a lot of talk around here about these things. Does anyone have, one, what is your experience with it?

Dual Case TacoBox, 4.0-liter 1GR-FE | Marlin Crawler, Inc.

Not an inexpensive modification, but really seems to take the truck to the next level. I think I would prefer this over the electronic version of crawl control we see in the 5th considering you can actually get torque multiplier benefit from the gearing... website shows an estimated 2000 ft/lb in dual low with a 206:1 ratio.

These crawboxes are super interesting. I don't "rock crawl" a lot per-se but when looking at doing lockers/regear the crawlbox has been something I have thought of as an alternative. I like the amount of vehicle control and think in a lot of crossed-up technical situations where a locker is used, this slow speed and amount of control might be able to reduce the times a locker is required. Sometimes, not always (as ideally you'd have both). Interesting discussion at least.

Regarding gas tank clearancing, we need [MENTION=28464]eimkeith[/MENTION] to build some F150 fuel tank kits for the 4th gen

 

[duffdog]

I don't see how it would change anything with ATRAC. I'm just guessing here but ATRAC could still be computed by comparing the input speed in the old tcase to the wheel speed sensors.

The reduction happens before the OEM t-case, not after, so the t-case and wheel speed sensor system should be unaltered theoretically.

Are you sure? It seems like Toyota wouldn't design something with that barn-door level of engineering. I'm almost positive that the computer is aware that the transfer case has been shifted into 4lo vs 4hi and uses an entirely new traction algorithm based on input speed and computed maximum wheel torque to prevent blowing up axle shafts. Either way, what is really needed is an INSERT that fits into the existing planetary case with no modifications of any type, reuses all sensors, doesn't cost very much, never breaks and allows the person to choose which ratio they would like.

Its easy to design something that costs a ton, doesn't really fit and might mess up the computer. That is not the solution I am looking for.

 

[Inv4drZm]

I'm almost positive that the computer is aware that the transfer case has been shifted into 4lo vs 4hi and uses an entirely new traction algorithm based on input speed and computed maximum wheel torque to prevent blowing up axle shafts.

It wouldn't surprise me at all if Toyota's ATRAC system was that simple. All it should need is the t-case shaft speed and each wheel's speed.

Yes, I would bet that the computer knows it is in 4 low and changes some things such as shift points, etc. But as long as the OEM case is in 4low in conjuction with the aftermarket case I don't see how the system would know it had a reduction box in front of the OEM case and need to kill the trac system.

But RST or Marlin would know for sure and it probably isn't worth further speculation at this point. If you have a crawl box you can likely afford lockers front and rear making ATRAC pretty useless anyway.

 

[Troymclure]

In the Tacomaworld thread I don't remember them mentioning the fuel tank issue, only the driveshaft lengthening/shortening.

Its an issue with the FJ's but they are a little shorter than us 4Runners.

I heard how they used to modify the fuel tank was to heat them up (plastic of course) and dent them out of the way, that or plastic welding a new panel in, though there was at least one instance where it leaked afterward.

We might be able to swap in the FJ fuel tank (18 gal) and have it all fit, not sure if it is much shorter than ours though.

Ive been looking into this as well, and we will have issues with the gas tank clearance. Wyatt also mentioned that 4th gen V6's would probably have to get rid of the ADD on the front diff, although I am not sure why, since the taco box just piggybacks off the stock t case.