NP231 doubler / crawlbox

[Wildman]

What does it take to make the electronic speed sensor signal work with the TJ?

Are you talking about for the Novak 300RX short output shaft?

They sell two different sensors. A 3 pulse which is what alter Jeeps used and the 40 pulse GM version.
The 3 pulse version is the same as a Rubicon signal I think.

I used a SuperLift TruSpeed to make mine work with the STaK's t-case.

But I don't know if they are made anymore. And I was thinking about trying the Speed Healer to see if it would work.

 

[LincolnJr]

Frog Fab also has the doubler boxes.

With the Novak short shaft and a doubler here is the total length.

You'd need to also run a flip kit, right? Is that additional length?

 

[Gollywomper]

You'd need to also run a flip kit, right? Is that additional length?

For running a 300? Only if the 231 crawler cover doesn’t have a clocking ring built into the design.

 

[Wildman]

You'd need to also run a flip kit, right? Is that additional length?

No the flip kit is to move the front output from a passenger side to drivers side drop. Of get one of the aftermarket D300 kits that allows a drivers side drop.

 

[someguysjeep]

I have that kit but it's rough. I was going to originally do that but decided to go with the doubler kit. If someone wants the parts for the NP231 doubler I can get all the parts and I'll sell it for 50% of that price, I'll never use it but it's going to require some fab work on their end.

if the OP doesn't bite maybe take a few pics of what you got and hit me up when it's convenient, no promises, but i'm considering my options.


so sounds like there might be doubts about a 300 being offset enough to reach the driveshaft past some auto trans bells, anybody got a guess on how it'd fit against the 42RLE? i read the front output is about 1" less offset than the 231.

Of get one of the aftermarket D300 kits that allows a drivers side drop.

sexy , but expensive, puts the atlas back on the table.

 

[Wildman]

if the OP doesn't bite maybe take a few pics of what you got and hit me up when it's convenient, no promises, but i'm considering my options.


so sounds like there might be doubts about a 300 being offset enough to reach the driveshaft past some auto trans bells, anybody got a guess on how it'd fit against the 42RLE? i read the front output is about 1" less offset than the 231.

I don't have the D300 measurements anymore but will try to find them.

sexy , but expensive, puts the atlas back on the table.

Yes but IMO there's good to both options.
And if you read about the LoMax gears they are supposed to be stronger than a Atlas.

 

[Gollywomper]

This is the midnight box but it runs D300 internals so flange offset should be the same.

 

[Wildman]

This is the midnight box but it runs D300 internals so flange offset should be the same.

View attachment 302869

I'll measure my STaK's box just for reference.

 

[Gollywomper]

For reference here is the atlas 2 I believe.

 

[Wildman]

My STaK's is 10" roughly. So about 1.44" wider than the D300.

And then the driveshaft is 2.75" outside diameter.

So a narrower driveshaft would help with clearance.

And 1" clearance between the driveshaft and transmission.

 

[Gollywomper]

Wow that is a tight fit.

 

[Wildman]

Wow that is a tight fit.

I need a smaller diameter driveshaft also due to clearance issues up front.

 

[pagrey]

I was thinking about trying the Speed Healer to see if it would work.

Probably will, the Speedo Healer is made for motorcycles and will work with any three wire hall sender as far as I know. Ain't much in common between a Kawasaki and our Jeeps but it works on both of them just fine.

 

[Wildman]

Probably will, the Speedo Healer is made for motorcycles and will work with any three wire hall sender as far as I know. Ain't much in common between a Kawasaki and our Jeeps but it works on both of them just fine.

I have one if I decide to keep the stock dash. But I also have a digital dash I'd picked up on sale I can use.

 

[someguysjeep]

the allure of the D300 is the ability to buy them fairly cheap, flip um fairly cheap and run um. the short length of the casing makes them good candidates for adding a doubler, and it can isolate that front axle operation. but no upgrades can make up for lack of output separation if 1 can't fit it.

And if you read about the LoMax gears they are supposed to be stronger than a Atlas.

a few considerations here, at least in my instance. i don't feel it as a come up to end up with just another 2sp and i don't think i'd want the D300 and lomax gears involved in a doubler situation with anything more than an additional 2.2:1 ratio.
2.72:1 compounded with a 2.72:1 leaves a 7.4:1, that's fairly deep, but usable, correct?
compound a 4:1 with a 2.2:1 or more and your gettin outside that desirable useable range now, correct?

i'm trying coming to terms with not finding a good alternative and having to go 3k deep to have what i want. but hey i got 6 months to save b4 it's ready to ship, ya?
the wheelbase increase created a turning radius loss, the ability to do a front dig efficiently is desirable and would be beneficial to me. unless i give that notion up, i really want that front axle isolation.
if i did let it go then 231/231 is cheap and dirty and gives me a deep gear option.

 

[Wildman]

the allure of the D300 is the ability to buy them fairly cheap, flip um fairly cheap and run um. the short length of the casing makes them good candidates for adding a doubler, and it can isolate that front axle operation. but no upgrades can make up for lack of output separation if 1 can't fit it.

The allure for you is that a D300 can be found cheap. If I was doing it I'd spring for one of the aftermarket cases but that's me. But I also understand the desire to keep it as cheap as possible too.
Well I think from the measurements we just looked at that YES it'd be tight fit but it also matters which automatic transmission you run.

a few considerations here, at least in my instance. i don't feel it as a come up to end up with just another 2sp and i don't think i'd want the D300 and lomax gears involved in a doubler situation with anything more than an additional 2.2:1 ratio.
2.72:1 compounded with a 2.72:1 leaves a 7.4:1, that's fairly deep, but usable, correct?
compound a 4:1 with a 2.2:1 or more and your gettin outside that desirable useable range now, correct?

I will disagree here again. I LIKE having DEEP GEARS. So a crawl box with 2.72 in it for mud & snow is great & then 4:1 for trail running. I've had 4:1 in a t-case before so I know what it's like. And that gives you the compound 10.88 crawl ratio. And when climbing some rocks or going down some steep sections of trails I've found that I LIKE having really low gearing. But that is ME.

i'm trying coming to terms with not finding a good alternative and having to go 3k deep to have what i want. but hey i got 6 months to save b4 it's ready to ship, ya?
the wheelbase increase created a turning radius loss, the ability to do a front dig efficiently is desirable and would be beneficial to me. unless i give that notion up, i really want that front axle isolation.

So honestly I think you have found a good alternative as Gollywomper has shown that you can do this swap for $2K. And you'll have the ability to do front digs and have the gearing you want since you won't be installing 4:1 gears.

if i did let it go then 231/231 is cheap and dirty and gives me a deep gear option.

Since you want front digs I'd do the crawl box & D300.

 

[Gollywomper]

The 300/eco doubler is a great fit for some. It won’t fit others as well. If you run a high HP rig with big tires and like to party then the 300 may not be for you.

 

[Wildman]

The 300/eco doubler is a great fit for some. It won’t fit others as well. If you run a high HP rig with big tires and like to party then the 300 may not be for you.

This was what lead to the replacement cases partly IMO. The stock cases would crack from guys running built V-8's & 36-40" tires. It's also why they came out with the upgraded front and rear output shafts from the stock 26 spline to 32 spline.
I haven't played with a D300 in years and back then it was in CJ5/7 and behind either a manual or a Turbo 400 or 700R4. So I can't comment on fitment issues with newer types of auto transmissions.

 

[freedom_in_4low]

Haven't watched it yet but this popped up in my YT feed this morning.

 

[Gollywomper]

I have an email in to Behemoth for their 205 case dimensions. I will update this post when I get them. The dimension on their site shows it roughly the same exterior as their 300 which I find difficult to believe.