Thanks for the tidbit, never really knew that...Looks like I will just put the stock duals in for now (a few months) and possible do 4.7 in the rear case down the road after seeing how the stocks do...

 

Just wanted to clarify i made a mistake on the designation on the 4cyl chain drive case. It is not a RF1A. Apparently RF1A is gear driven. At least according to my 93 FSM. Toyota put the VF1A behind the G58 equipped 22re's. If that's the case then you could probably use the Marlin V6 adapter. See the attached file.

 

My truck is getting its 3.0V6/R150F/VF1A swapped out for a 2RZ/R151F/dual ultimate crawler with 2.28/4.7 for a final low range of 244:1 (4.31x2.28x4.7x5.29=244). My buddy has a Rubicon and he is always trying to talk me out of going dual case since I will be able to outcrawl him! He claims that he will have to get an Atlas 10:1 case. Jeep guys....

 

OK, I've been toying (no pun intended) with the dual cases since the summer and have been digging for info, this seems to be the thread with the know how so I'll ask here.
I have the typical 3.slo/5 speed/whatever case, I'm looking at using the Trail Great adapter. Not know spline counts and what not, can I use it? What do I need for a second case? What happens to the output on the front case? I'm not the mechanical one, I have a buddy that does all of that, so I haven't presented this to him yet, want to have all the ammo I can.
Excuse the newb Q's.

 

There are a variety of threads on this here Twinkie, but since you have a 3.0 five speed, let me sum up your options:

For both of these options, the following applies - you can reuse your crossmember, but a dual case one is highly recommended. You will have to have your front driveshaft lengthened and the rear shortened. I would also look at twinstick on the rear case, but that's totally optional.

OPTION 1 - the "old fashioned" way
You can get an adapter to put two gear drive cases behind your tranny. You will have to buy 2 gear drive transfer cases, a V6 adapter, and a dual case adapter. If you don't find turbo tcases, you will have to upgrade them to 23 spline. This way is proven over many years of history, but the gear cases do make more noise and in my experience get bound up in 4WD easier. Adapters are available from a variety of sources - TrailGear, Advanced Adapters, Marlin, Inchworm, etc (all but the Marlin are made by Advanced Adapters on an older Marlin Crawler design)

OPTION 2 - the "new" way
Marlin Crawler now makes the MC10 adapter which allows you to insert a crawlbox between your tranny and EXISTING chain drive tcase. You buy the two adapters and a gear drive case. This option is considerably cheaper. For people who say the chain drive case won't hold up, chain drive cases are holding up fine behind 4.7:1 crawl boxes and supercharged 3.4's and even Tundra V8's with no issues. The chain drive case is quieter and smoother than the gear drive and has a slightly lower reduction ratio (2.56 vs 2.28 for gear drive).

I was all set to go with Option 2 in my rig, but I came across a used gear drive setup (4.7's, adapters, crossmember, twinstick - everything) for cheaper than I could have done just the minimum MC10 setup for.

 

http://www.marlincrawler.com/htm/tra...up_dual.htm#v6

 

After posting I did make my way to Marlin's site...wow, talk about sticker shock! For my type of wheeling I'm sure the crawler box will be the route I go. Finding 2 gear drive cases up here wouldn't be hard, but converting to 23 spline and cost of adapters makes it pretty pricey. When the time comes it looks like it'll be a MC10-R10-U.

 

Expensive?

Perhaps you were looking at the wrong thing? This entire mod can be done for under a grand. That includes Drive shaft mods, and a crossmember. Not much under, but a little.

As tcase gearing goes, that is extremely cheap. A STAK monster box retails in the 2500 range, as does an Orion.

 

I was closer to $2k and I thought I got a deal... I'd like to see how you could do it for $1k

 

Just chimming in--but great thread

 

Just chimming in--but great thread

 

Just a question--i know there is the "Lefty", Atlas, Stak.....does anybody know of other options for us driver droppers?

 

you have the option of the lefty adapter and using MCs total spline 4.7 gears in a gear driven case as well, however you would need the v6 auto adapter to geared case,

converting to 23 spline is only like 170 bucks or so.

my dual setup when i do it, is going to be dual geared cases with the lower gearing in the rear case instead of the front case, puts less torque load through the drivetrain, also for anybody going low gearing, get a cromo output shaft on it please

 

i guess i should clarify--i am manual--3rd gen, V6--took me forever to get find this truck.

So Lefty adapter, Then two gear drive T-cases? Plus drive line work?

 

im not sure how you would mate to a v6 manual, something you would need to call Jim at inchworm about

but yeah you could pretty much go dual gear drive cases, and put the lower gearing in which ever case you want, but with the mathematics, the torque load is less with the 4.7, 5 or 5.7 whatever you want in the rear case.

would need it to be 23 splines though of course.

 

Thanks--sorry for the slight hijack also folks--I am just getting under way on a major build and weighing options--all in all i am thinking i might just find a used driver drop 4.3 Atlas/Stak and go that route. If only they made gears for the Chain Drives......("looks off into the distance").

 

I think the difference of the 4.7's in the front or the rear case is kinda a moot point - the shafts are all the same strength, and the peak torque is still on the output.

All that said, I would put them in the rear case because then your 2LOW is with the higher ratio which is probably more appropriate for the conditions you're likely to use 2LOW in.

 

You are right, 1100.
350- adaptor
100-150 transfer case
~400 driveline mods
xmember 200

Total- 1050-1100

 

Oh - you're assuming a 4cylinder and you have a gear drive case already and don't need the V6 adapter, 23 spline conversion, or 4.7 gears. Gotcha.

gonna be closer to $2k for a V6.

 

Ah. Yes, I didn't even look at that. My bad.

Yes, for 4cyl 5 speed guys, this is cheap. Not so much for v6 guys. My bad. Sorry for the confusion.