What's Dual TC for?

[Kevin B.]

I see a lot of references to dual transfer cases, and I'm confused. Is one a back-up, or are they both functional at the same time?

Are they connected in parallel, or in series?

 

[SAMI]

That Magna water is doing a number on you buddy.. I kid, i kid... but it does taste funny..

Dual T-cases allow the operator to have deeper gears resulting in a lower crawl ratio by stacking two, and in some retarded cases, three transfer cases on eachother. They can be somewhat of a headache, but you do gain a lower crawl ratio and 2WD low, which I enjoyed. It gives a load of gear options, which ends up being a pro and a con depending on situations.. Popular choice due to the inexpensive nature of an OE t-case.. Just grab an adapter and add to/replace the tcase skid and your good to go.. Oh, and the driveline will most likely need shortening..

Anyways.. The dual case is for the toyota nerd world..

 

[Spork]

Dual transfer cases give additional gearing options
stolen from Marlin's site
http://www.marlincrawler.com/java/getratio.html

Here is how to calculate your overall crawl ratio.
It's a simple formula.

Multiply your first gear, times your low range transfer case gear, times your differential gear. For example if you have:
3.93 first gear in your transmission
2.28 low range gear in your transfer case
4.10 gears in your differentials
Your crawl ratio is 3.93 X 2.28 X 4.10 = 37:1

If you have two transfer cases then you also multiply the number by the second case like this:
3.93 first gear in your transmission
2.28 low range gear in your first transfer case
4.70 low range gear in your second transfer case
5.29 gears in your differentials
Your crawl ratio is 3.93 X 2.28 X 4.70 X 2.29 = 223:1

 

[RockMonkey]

It's really a transfer case and a half, since you're only using the gear reduction portion of the first transfer case.

 

[Kevin B.]

Ah, because the same effect in a single case would make it too big. Thanks for answering the n00b question, all.

SAMI, I haven't had a drink of Magna water since the day I moved out here, that's some foul liquid right there.

 

[RockMonkey]

Ah, because the same effect in a single case would make it too big. Thanks for answering the n00b question, all.

SAMI, I haven't had a drink of Magna water since the day I moved out here, that's some foul liquid right there.

No, it would make it too expensive. Atlas and Stak both make multi-speed transfers cases that achieve the same effect in less space, but they're many times more expensive.

 

[pELYgroso]

Dual cases Rule. Basically, you have your normal t case that will lower your gearing from 2wd high to 4lo, right? Then, with a second case behind that, you can transfer the normal 4lo, do a 4wd double low, lowering the stock 4wd low the same amount again, that you went from 2wd high to 4lo in the first place. =idle up just about every obstacle, unless your tires don't grip, in which case they just sit there and spin. No gas, no clutch....I love it!

 

[LT.]

Dual cases is the way to go. Not only do you get lower gears but, you can also have a longer front shaft. This makes having both shafts the same length a reality. Then one spare is all you would need. You also can gain 2wd low range and front wheel drive only. Both have their benefits as well. Top that with the ability to find parts at any local store and lower cost you have a winner.

 

[90 cherokee]

swashbuckler, if your in the murray area and wanna see/feel what dual cases feel like ide be glad to show you, ill pm you my number.

 

[90 cherokee]

o and welcome to the forum!

 

[Panos]

Welcome, atleast you're asking about a toyota haha are you planning on a build soon?

oh and stay on this site, if you are going to ask questions like this, dont even think about going over to pirate4x4, you might not come out alive if you where to ask this over there.

 

[BCGPER]

Dual cases are to the Toyota guys what Corvettes are to old dudes. They really do help what doesn't work all that well look a whole lot better.

 

[I Lean]

Dual cases are to the Toyota guys what Corvettes are to old dudes. They really do help what doesn't work all that well look a whole lot better.

So you're shopping for another Vette?

The above pretty much covers what a Toyota dual 'case is all about, except it does NOT give you the option of front-wheel-drive only. That's one thing a Toy Tcase is incapable of.

 

[utah340six]

duel cases

Dual cases are to the Toyota guys what Corvettes are to old dudes. They really do help what doesn't work all that well look a whole lot better.

there are dual cases out there for jeeps also.
one is made by dd machine gear box
bolt on front of 231 gives extra low range.
same as toyata guys do. 700 or 800 bucks.

 

[BCGPER]

They quit building Corvettes in 1970, as far as I'm concerned. So no, I'm an old fart in a Caddy....

So you're shopping for another Vette?

The above pretty much covers what a Toyota dual 'case is all about, except it does NOT give you the option of front-wheel-drive only. That's one thing a Toy Tcase is incapable of.

Wait a second..... Didn't that old shifter mod, like Von was sporting in his UROC years, give him that ability? Maybe it was just the two wheel low option, I don't remember.

 

[I Lean]

2 Low you can get with a twin-stick, but the only way to get front-wheel-only is with a rear driveline disconnect....there's no way to do it internally to the Tcase.

 

[BCGPER]

That's what I was thinking (of course, after I posted that), that mod gave you low range rear drive only. No matter, if it's not a competition vehicle front only drive is kind of stupid anyway. I had it on a few, but never really found a use for it. But to get back to the original subject, dual cases on an underpowered Toyota are almost mandatory. They will get you places that monster engine won't.

 

[Kevin B.]

Welcome, atleast you're asking about a toyota haha are you planning on a build soon?

Not that kinda build, no, leastwise not soon. Just had seen it mentioned and wasn't finding context. So I asked.