what are they? i searched and have yet to get a few basic answers:

-what are dual t-cases?
-what are they for?
-where do you get them from?
-are they available stock on anything?

i know i'm not new, but i thought that since this was a simple question (or is it?) that i'd post it here

 

Dual cases are two transfer cases put into one case it offers to different options for 4lo 2lo and such typically you have stock gearing in the front and 4.7 gearing in the rear u can choose from either of those or you can select both for double low. They don't not come stock marlin makes premadr cases or u can get an adapter and do them yourself. I think also u can select front or rear wheel drive with them

 

Irab88 - Dual cases is exactly what Vance just mentioned, but i'll add a few things You can only use 4 cylinder transfercases. the v6's aren't compatible. so if you plan on doing it, make sure you use the one you have with another 4 cylinder.

Honestly, If you don't know what they are, you probably aren't ready to use them. Go wheeling around for awhile, you'll probably meet someone that has dual cases at some point, ask them for a demonstration when you see em.

 

so are they the gears from one case put into another housing, then bolted on to the stock case? and i could select 2wd in the front?
same thought here. when i learned to drive stick, it was a challenge. but the instant my dad told me how it worked, off i went. there are just too few people in the n.va area to go wheeling with.

i'm just trying to get my knowledge on

 

More correctly it is 1.5 t-cases, reduction unit off the front of one case bolted in between the transmission and the rear (full) transfer case.

And you get two shifters (plus the trans), with hi-low in front and 2H-4H-4L in the rear. You can shift the front into low range and have a 2L range. Plus you get the double low ranges:
- http://www.4crawler.com/4x4/4R_TechI...l#Transmission

 

The answer to your question is fairly simple. Dual cases are a transfer case (like what any 4wd vehicle comes with to allow 4-low) with a gear box from another transfer case piggy backed together. This allows you to "double" your 4 low gearing, which turns the tires slower than stock 4 low and provides more traction. The difficult part of your question is the order of assembly through the years, which is something I'm still confused on. I believe, for our model trucks, we would take a full tcase out of a 79-83 model, make that the rear tcase, then take the gear box of our stock tcase, get an adapter from Marlin or Trail gear, and place that between the 79-83 tcase and our transmission. You also have to shorten your rear drive shaft and lengthen your front drive shaft.

Someone please correct me if I'm wrong on that 2nd part.

 

Here is a picture of what a duel case set up looks like.

 

Dual cases are what you need to carry your dueling banjos.

:wabbit2:

 

sorry to hijack, but is there a difference between forward shift cases verse top shift when it comes to running duals? do you need one or the other or can you conjoin them?

 

ah-ha! got it! so it just "doubles" the low gearing of the stock case (i think?)

 

Rear case must be top shift or converted to top shift.

Front case must match your tranny.

:wabbit2:

 

>sigh<

 

yep you want your cases to work together, not fight

and to throw more stuff out there, they need to be gear driven, chain drive cases won't work.

than start thinking about 21 vs. 23 spline outputs.

and if you think 4.7's gears in a single case is the way to go...some folks do, i say no, too low if you still need low range inbetween obstacles, advantage is cost...i like my dual 2.28x4.7, 20 forward speeds and 4 reverse...220:1 in double low...that is when my truck isn't broken

 

Wow, so yeah...

"Stacking" on another TC lets you have the option of using either the low stock crawl ratio of 2.28 in low/high, or 5.19 in low/low.

2 TC's, get it?

And that's just with stock gearing.

You have 2 TC's now so you can put low gear sets in both, if you want to.

Or, you can bolt 2 transmissions together... But I won't confuse you with any more on that subject.

 

[quote=tried4x2signN;51565536]

"Stacking" on another TC lets you have the option of using either the low stock crawl ratio of 2.28 in low/high, or 4.56 in low/low.
quote]

I thought double low with stock would be 5.2 since the gear ratio is being multiplied by the gear ratio? Making a 2.28/4.7 set up 10.7 in compound.

 

I thought it was off too, but my calc says 2.28 x 2 = 4.56...


Whoops, yes you are right. I did 2.28 x 2 which IS WRONG.

You are right, 2.28 x 2.28 = 5.19 might as well say 5.20.

 

that is when it gets really confusing

I figure my low low as 3.90 (1st) x2.28 (1st TC)x 4.7 (2nd case)x 5.29 axle=220:1

 

all right, thanks guys. i got it now. i had it in my mind that somehow you could independently control the front and rear, as opposed to just lowering the gearing.

 

you ca do that w/o dual cases... That's called a "Twin Stick"

Though I think on a Toyota you can only disengage the front axle. Good for tight turning situations.

Whereas with a NP205, you can independently select high neutral and low for each axle, independently

 

if you go with a rear DS disconnect, I think Front Range off road makes one, than you can get true front digs..
edit: found one from trail-tough--would be nice if you flat tow:
http://www.trailtough.com/index.php?...hk=1&Itemid=53

As far as the twin stick, it is nice having the option for 2WD lo, and Lo lo, especially when my locked front end is binding,