dual cases????????? (1 Viewer)

[notyourmomslx450]

do you have a press? that's one big thing that makes it easier. I don't know much about the AA version, since I got the Marlin clocked adapter, but read through the instructions berfore you start and keep them handy once you start. This isn't your daily driver is it? I'd suggest putting together the crawlbox (front case) and adapter prior to pulling your t-case to shorten vehicle downtime.

 

[Baja Dan]

its my daily driver but ill just drive my fj80 for a week i got 2 transfercases not counting the one thats in the truck right now so the only hold up will be on my driveshafts. anything that i need to know before i start putting the cases together..?????????

 

[notyourmomslx450]

not really. just read up online as much as you can so you'll be ready. I know Marlin has a really good set of instructions, and you can find all kinds of writeups online as well. You'll need a new crossmember for it, too. I have the front range one for mine, and it only required a little grinding here and there to work on my '94.

 

[notyourmomslx450]

where are you located?

 

[Baja Dan]

im in san diego cali ive been reading the directionson trail gear the only thing that has got me alittle confused is the welding of the the key stock on the sift fork not really sure what thats for ?????????

 

[acemechanic71]

I have 4.10 rears, 35", and single with 4.7 marlin gears and i love it, plenty low enough for the trails in tucson. I plan to do a dual case later. There is a three shifter option for one single hole in the floor with the dual cases. cant find the link right now, but i saw it on pirate4x4.

 

[notyourmomslx450]

you remove one of the shift forks from your front case when you set up the duals, because it loses the 2wd-4wd function. In order to make the shifter stay in place, you weld on the keystock to the remaining shift fork for hi-low range. It holds the shifter from moving laterally from where it needs to be. Basically, it looks like this:

 

[axed existence]

I have 4.10 rears, 35", and single with 4.7 marlin gears and i love it, plenty low enough for the trails in tucson. I plan to do a dual case later. There is a three shifter option for one single hole in the floor with the dual cases. cant find the link right now, but i saw it on pirate4x4.

35" on 4.10? Wouldnt that be a very very slow truck?

 

[notyourmomslx450]

with the 4.7s, it wouldn't really matter if it's a trail only truck. It would bring the suck w/ a 4cyl on the street though, i bet.

 

[acemechanic71]

Its not that bad on the street, have to put my foot on it to get it up to trafic speed. After that its good. Its great offroad. I am also upgrading to 5.29 gears when i get the cash.

 

[Baja Dan]

thanks for the info on the shift fork ill tig weld it today at work

 

[the truck doctor]

it sounds like the norm is to have 4.7 in the rear case and stock in front. why not visa versa?

 

[notyourmomslx450]

IDK. I guess because I like to have 2low w/ 2.28s. Someone told me once, but I don't remember.

 

[Devil's Slide Doug]

I believe marlins website would give you the best answer. But in a nutshell, There is a concern with busting (stripping the splines) of the input shaft of the second tcase. Less chance of this if you put the lower gear in the rear case. If you are worried about input shafts then you can research about the different sizes available and which doublers are best (details like bearings and such). Marlin verses advanced adapters verses inchworm. I think longevity/reliability also depends a bit if this is a trail rig or daily driver, motor, skinny foot application, tire size, etc.
Marlin Crawler : Understanding the Toyota Dual Case Crawler

"In our opinion, the Ultimate setup is when a dual transfercase is built with one set of stock gears (2.28:1), and one set of Marlin Crawler's 4.70:1 gear sets. This is known as the Dual Ultimate Crawler. In a 21-spline application, due to the excess torque generated by the 4.70:1 gears, we will only build a 21-spline Ultimate Crawler with the 4.70:1 gears in the back case. But in a 23-spline application, the factory 23-spline input is much stronger, and therefore, the 4.70:1 gears can be placed in either the front case or in the rear, the choice is yours. In any of the available applications, two sets of 4.70:1 can be used to achieve a low range crawl ratio of nearly 500:1! More than 9 times lower than stock!We call this a Dual Ultimate Overkill Crawler since such a low crawl ratio is merely for bragging rights."

 

[fortysixandtwo]

"We call this a Dual Ultimate Overkill Crawler since such a low crawl ratio is merely for bragging rights."

What he said. Having the 4.70s in the front case is really completely impractical and not very useful. Kind of like tripple cases. Marlin did it because he could, but in a real world wheeler the options you get with 2.28/4.7 are plenty. I have no need for any lower gears or more gears for that matter. The Dual Ultimate set up is the way to go.

 

[Baja Dan]

howdy fellas well i finally got my transfer cases put together. it wasnt as difficult as i thought ive been doing it little by little havent had much fre time. i got my stock t case torn off today just waiting on a gasket and some help from a buddy to hold it up. i ended up going withtwo 2 2.28's well see how that goes.

 

[aadown1214]

Sorry to spawn another conversation here, but i noticed at the top someone said with a 4.7, its easy to grenade a clutch.........care to elaborate? Do you mean riding your gears down a steep decline, or just in general? anyone's comments welcome, im working towards duals on my 80 model

 

[2ndGenToyotaFan]

With a single set of 4.7's it's not an issue, but when you go to duel cases with 2.28 & 4.7 or 4.7 & 4.7's if you roll the truck in low-low all that gear reduction can spin the clutch plate up to 20k+ rpm's pretty quick... and the clutch isn't designed to take that. So you have to remember to take the trans out of gear....

 

[missouriman]

With a single set of 4.7's it's not an issue, but when you go to duel cases with 2.28 & 4.7 or 4.7 & 4.7's if you roll the truck in low-low all that gear reduction can spin the clutch plate up to 20k+ rpm's pretty quick... and the clutch isn't designed to take that. So you have to remember to take the trans out of gear....

x2..
my wifes 2.28 and 4.7 is very low. if you are in low low, 1st gear and coast even a little ways you will hear the clutch spinning up.

to be able to hear it I hate to think of the rpms it is hitting.
I explained it to the wife and she understood and has not done it again. I would guess that she only hit 5 mph. but sounded like a dremel tool.

 

[notyourmomslx450]

I haven't had that experience. I use mine to go down hills in low/low all the time, and haven't ever had the clutch slip. My truck just inches down the hill.