I have A LOT of questions about dual transfer case setups. So, maybe this thread will fill up with a good, central source of information and we can "sticky" it.

I have a 1996 4Runner, 3.4L, A340F auto, e-locked rear, soon to be Aussie-locked front, and soon to have 4.88s.

I also have the transfer case from a 1983 Toyota pickup. It sat behind a 5-speed manual. I don't know which model transmission it had.

Here are my questions:

1. Can this transfer case be used behind my A340F transmission?
2. What is needed (adapters, etc)?
3. Can the average home mechanic (me) complete the installation of a dual t-case setup?
4. Other than new front and rear drivelines and modification to the center console, what other modifications are needed?
5. Is it worth it?

Is there any other information you can offer that might be helpful?

 

1 - yes, but you will need to convert it to top shift
2 - Marlin's A340F->gear drive tcase and Mariln gear drive tcase -> your tcase. Plus shorter rear shaft and longer front shaft. Possibly interior mods and crossmember mods.
3 - sure
4 - crossmember, possibly lengthening the speedo cable.
5 - only if you wheel.

 

1. How do I do that?
2. Marlin's A340F - I have to replace the whole tranny?!?
3. Cool
4. Are longer speedo cable availble commercially?
5. I wheel, but not "extreme".

 

1. http://www.marlincrawler.com/htm/tra...c.htm#topshift
2. he is saying the adapter to connect your A340F to the reduction box of the old tcase

 

I just put one of the Marlin dual ultimate crawlers in my rig this past weekend. Big job, but I am very happy with the results.

Mine has a 3.0 5spd, so I can only offer some help. I got the 3.0 to 4cyl TC adapter from Marlin.

Keep in mind that the majority of Toyota 4cyl transfer cases have 21 spline input shafts. My 3.0 tranny had a 23 spline output shaft. You will need to change your case(s) so they both have 23 spline for strength and compatibility.

The job can be done with standard tools. A tranny adapter for a good floor jack is very helpful. Angle grinder and a welder/ or torch might be required as well.

Speedo extension can be purchased from Marlin. I got one, about 6" long. Very helpful part. You may also wish to purchase their multiple hole pattern flanges. You'll have a better shot of matching up to you newer driveshafts without having to re-drill. Also consider getting a boot for the new shift lever to help keep down road noise, dirt... and give a cleaner, more finished look when you are all done.

Can find all those parts on this page:
http://www.marlincrawler.com/htm/tra...e/tcase_ac.htm

I had to modify the shift levers themselves to make everything fit together. IN a 5spd, I've got three sticks I needed to make clear each other in all configurations. I got close, and can get every combination but 4th and 4.7 low... but I have an idea about that to try later.

You may have less issues with an auto, but to change stick angles I used a welder. Others have had luck with a torch and bending. The problem with both methods is that there is a hard rubber sleeve that mates the upper lever to the base stick. Once that melts... shifter comes apart.

In my opinion, the crawler is more "worth it" if you currently have a manual tranny. Although I have not driven an auto with a crawler, the rigs I do runs with that are auto equipped can generally modulate their speed pretty well already. I guess the increase in low end torque might be nice. I'd like to learn more about how a crawler helps guys with auto trannies.

 

Or I could just save myself some time and install this:
http://www.marlincrawler.com/htm/tra...e/taco_box.htm
It's only $150 more than building my own.

So now my question is:
With the TacoBox setup, it's apparent I have to relocate my push-button 4WD lever back. Or do I retain that lever at all? Is it simply replaced?

 

inchworm also has a tacoma double case setup as well...in a gear driven flavour ala pre taco tcases. http://www.inchwormgear.com/store/index.php?cPath=21_38

i'd guess your 4WD push button can go in either front or rear t, since its only a switch. the 2 levers will let you choose your combo of 4hi, 4 low, or 4 double low.

 

Be sure to talk to Flygtenstein - he has the setup you're looking at.

 

Am i missing something? Doesn't he have a tcase that is the wrong drop? I could be off, just asking for clarification.

 

Doing the cases in and out took me an afternoon with help.

Putting them in from a stand still having never done it before would be a handfull, the coupler is a turd.

I have a passenger drop front, you do not.

I am not sure I have seen this done with the push button case.

It is worth it. With the auto, I do most wheeling in 4.7 low. I use stock low for wheel speed obstacles. I use double low to entertain myself at parties.

 

I think this is a pretty important thing to consider. You are more of a wizard than a mechanic...

I am a moderate mechanic. I can do most things, but i cannot do them fast. I only did a single case, and it took me 12 hours driving to driving. I did it in a regular garage, but was using air tools, and everything...even there, from start to case out and apart, took me 5 hours, the rebuild took another 4 and then 2 to get it back in (hour for lunch).

I would imagine, for me, trying to do both cases at once, probably 15-17 hours.

 

I went with the Taco Box.

The swap took me and a buddy about 8 hours in the driveway.

The biggest bugger for me was getting all 3 shifters to clear each other, the interior, and the body.

Cheese is right the coupler is weird, especially since there are no instructions.

(Cheese, I think my coupler is different than yours, the newer design places the tranny output seal inside the front case with a machined aluminum extension)

Tips:

Get a set of drive shafts made up ahead of time

Be prepared to weld, test, re-weld, test, re-weld, test the shifters

Get a good tranny jack

Opinion:

With an auto a second stock case may be low enough (save $500 over the 4.7)

Question:

Since you haven't wheeled with 4.88's and a front locker yet, why look into a dual case now?

 

I went with the Taco box and it took me about 3 hours to install the box and drive shafts. (that I purchased ahead of time, then had modified before hand)

It took another hour just to get the shifters to set in just right, so they all cleared each other. Once this was done about 2 more hours modifying the cup holder and adding the boot, but that was done about a week later.

 

From the guy that did an engine replacement in 2 hours!