How is the shifter going to work for the extra t-case? I assume you are going to have to install another shifter next to the one from the factory?

 

First thread I've read or guy I know to run a doubler with NP231s. I'm interested to hear how it plays out. Keep us updated if you don't mind once you get it out.

 

With the deep ratio and an auto it gives you the same control as a stick.

 

I am going to make up a push pull cable to operate the range box shifter. I am also going to grind of the 4h, and the nuetral detents off of the shift mechanism in the t-case.

If you look on pirate on the dodge board there is a guy running 241/241 which are bascially a lil larger version. Worse comes to worse I destroy a 231.. and put a d300 behind it. I am searching for the wider chain parts as well as some 6 planeteries. We wil see how it plays out


thats what I have been told... I just dont think you get the compresion braking with the auto I wil be geting with the manual. Dont get me wrong..My MJ truggy is going to be an Auto, and it is going to have a 203/300 doubler, but It wil have 5.38 gears and 42's. So I should have plenty of control with that.

 

Very interested, though I see a cracked case in the near future

 

You would be amazed at the power at the axles with that ratio. If I put it in 2wd 10.38 and 1st gear even with the 1750 stall in my 4L60E tranny, putting my foot on the brake stops the front wheels and the rear wheels just spin an did a couple of holes while the engine idles. Going down a steep hill, it is just about impossible to stop it with the brakes. You have to shift it out to do it without having the rig buck and lurch. The same power is there on compression. Assume a measly 50 hp at idle. 50X10.38 = 579 horsepower for forward motion or compression. That kind of horsepower makes a big difference.

 

Duffy has close to 1000 kits out there.. no cracked cases yet. And If I crack a 231 case.. they are not that hard to find.

I am currently searching j-yards for a hydro boost set up for the brakes... and doing the WJ knuckle/brake conversion.. so with all the brake mods I have planned I should be able to slow it down

 

Which case?

 

The only bad thing I see happening is the chain streching possibly breaking. Thats what I see possible.

I am still researching how ppl are supporting it, with out creating torque bind. More to come on that as project progresses. I think I have everything in motion to make it happen.

 

Personally (having run this exact doubler in two different vehicles) I would NOT use the NP231 behind the doubler.

The 231 isn't a "tight" box to begin with (Chain slack) and when you add the extra gear box the free play begins to add up.

It gets REALLY annoying if you add a detroit to the mix.

Get a D300 for the rear box. (And you can twin stick it for true independent axle selection: front digs, etc.)

Besides, it's a more compact package.

 

my klune came with a mounting plate, that goes behind it and helps support the weight of both cases. however, i am also going to make a mount for the dana 300 i have, and a torque arm or 2. here's a decent thread from pirate, shows you how one dude did it:
http://www.pirate4x4.com/forum/showthread.php?t=878186

 

Thanks for the comment. I do have a 300 in the garage but that is for another project. I will try it with te stock parts while I try and find a 6 gear planetery and the wider chain.

I plan on running a mini spool or a lincoln locked rear so I expect great handling attributes.

As far as being able to do front digs.. I know a bunch of ppl with twin sticked t-cases and I have only seen it used one time.. and that was to just show it off.

 

I would agree with that too.

 

Thats a pretty stut looking mount. What I have seen and been told by a few ppl running this that there can be torque bind mounting it that way. What has been suggested by several ppl was to build a cutom trans x-member that also mounts to the doubled t-cases. I am stil working out the details on it

Well I have done a bunch a research on this... and this guys build convinced me that it should hold together.http://www.pirate4x4.com/forum/showthread.php?t=765900

 

1. I'm not saying it won't work, or won't last (not break)...I'm just warning you that you will probably find that combination has much more slop than a gear driven case behind the doubler.

2. Rear mount: Running the 231 will be in your favor here: Given how light the 231 is, I wouldn't worry about the second support.

Get some good FRONT mounts, and don't worry so much about the rear... the rotational deflection is mostly handled by the fronts. the rear mount really only provides vertical positioning.

I ran my CJ without the rear mount connected for longer than I care to admit, and the only thing that clued me in was landing on a log hard, and noticing the stick shift bounce...

-Chris

EDIT: missed this before...

I ran my YJ Spooled in the rear (with the doubler)... the D300 allowed me to "front drive" (front dig w/o the cutting brake) and make the turns... keep in mind I was stretched to about 100", and the spool/ wheel base SUCKED w/o the front drive option. But I LOVED the spool for the stability on the street, and the braindead, "always on" functionality.
Besides, it was a hoot to scare the ****e out of little old ladies as I turned into gas stations to fill up... little turn:
Jeep: "Eeerrck, screech!"
Little old lady (with absolute TERROR in her eyes as I trundled along at 2 MPH) "SLOW DOWN YOU JERK!!!"
Jeep (giving it a little gas while turning sharper): SCREEEEEEECCHHHHHHH! RAWRK!
Little Old Lady: runs around the car and hides while giving me the stink eye.