NP231 doubler / crawlbox

[Wildman]

Sounds like a good time to get in before it's well known and available. Could have parts ready to go.

The only issue with the NP205 is the limited gearing options.

1.96:1 is the stock crawl ratio.

Then you only have a few options past this.

https://www.offroaddesign.com/np203-np205-doubler-kit.html
https://www.offroaddesign.com/offroad-design-magnum-underdrive.html
https://www.northwestfab.com/NP203NP205-Dual-Transfer-Case-Adapter-Kit_p_3475.html
https://www.northwestfab.com/titan-series-np205-blackbox-i_p_3968.html

 

[JMT]

The only issue with the NP205 is the limited gearing options.

1.96:1 is the stock crawl ratio.

Then you only have a few options past this.

https://www.offroaddesign.com/np203-np205-doubler-kit.html
https://www.offroaddesign.com/offroad-design-magnum-underdrive.html
https://www.northwestfab.com/NP203NP205-Dual-Transfer-Case-Adapter-Kit_p_3475.html
https://www.northwestfab.com/titan-series-np205-blackbox-i_p_3968.html

ooh, I like that magnum underdrive. 1:1, 1.96:1, 2.72:1, and 5.33:1

I'm probably dreaming.

 

[someguysjeep]

the 203 in front opens you up to needing to mate the trans. most literature i found said you want parts from the donor TC's trans or make accommodations for an adapter, i'd assume is a longer spacer.


and then there is this i found............."A 203 / 205 doubler has enough weight as it is. I think I remember it weighing around 280 lbs."
if that's true that's way beyond pig. and the weight of a smaller crawlbox increases it's worth..

 

[Apparition]

ooh, I like that magnum underdrive. 1:1, 1.96:1, 2.72:1, and 5.33:1

I'm probably dreaming.

That’s nearly the same ratios as Jeff’s 4-speed Atlas

 

[Wildman]

the 203 in front opens you up to needing to mate the trans. most literature i found said you want parts from the donor TC's trans or make accommodations for an adapter, i'd assume is a longer spacer.


and then there is this i found............."A 203 / 205 doubler has enough weight as it is. I think I remember it weighing around 280 lbs."
if that's true that's way beyond pig. and the weight of a smaller crawlbox increases it's worth..

These are the reasons for getting the aluminum case for the NP205 and then a Crawl box my guess is you'd be less weight than stock.

And getting one of the crawl boxes fixes the need for a transmission adapter.

 

[someguysjeep]

well i might have some info on the output spread of the 205 next wkend.
i found 2 Ford NP205's, driver drop and round bolt pattern, both should have 31 spline inputs. guy will give um up for 100$. so he's gonna get um out this wk and unless the weather is bad i'm gonna go snag um next wkend. for 100$ and a couple hrs of piece and quite in the truck i'll be the guinea pig.

and i can't find info but i did get a look at some pics of a divorced Ford case and those are not as bulky as any of the married cases look to be, i just don't know if there is anything different to swappin inputs, haven't had time to dig for that yet.

 

[Wildman]

well i might have some info on the output spread of the 205 next wkend.
i found 2 Ford NP205's, driver drop and round bolt pattern, both should have 31 spline inputs. guy will give um up for 100$. so he's gonna get um out this wk and unless the weather is bad i'm gonna go snag um next wkend. for 100$ and a couple hrs of piece and quite in the truck i'll be the guinea pig.

and i can't find info but i did get a look at some pics of a divorced Ford case and those are not as bulky as any of the married cases look to be, i just don't know if there is anything different to swappin inputs, haven't had time to dig for that yet.

Damn that is some great prices. I was looking on Marketplace locally here and a NP205 is going for $500-1,000. And I'm talking nasty grease caked who knows what kind of shape stuff.

 

[someguysjeep]

Damn that is some great prices. I was looking on Marketplace locally here and a NP205 is going for $500-1,000. And I'm talking nasty grease caked who knows what kind of shape stuff.

they got some rusty cases but he says they turn easy. most others i found were 200-350$, same for the D300's, that frog kit could make my 231 my doubler, but i got 2 of them on the line for 100ea as well if needed.
and there is a 241C close for 50$ i was considering snagging just to salvage that planetary and make me a 6pc.

now IDK if i want the cases or just the guts but it'll give me hands on to see what can be trimmed away or changed or if it's just heavy trash.

 

[someguysjeep]

more BS just in case anybody goes lookin for salvage units.

Ford is the best option to find a driver drop case, Chevy and Dodge are 95% passenger drop.
most of the Ford units use a 6 bolt round pattern and should have a 31 spline input, while most Chevy and Dodges use the figure 8 pattern and have multiple spline possibilities.

adapting 1 directly to the 42RLE could prove, fun. and would/could require an input change to the 205 TC.
best bet at this point might be to go ahead and use a doubler to make that connection, and the connection from the doubler to the 205 is market supported.
IIRC, the blackbox or ecobox claims to come out just an inch longer than the NP231. for a 42RLE this puts a Rubi Crawler into a nice place cause it'd replace the tail of the trans to stay short and can be fit to adapt the 205, i'd think..

 

[Gollywomper]

more BS just in case anybody goes lookin for salvage units.

Ford is the best option to find a driver drop case, Chevy and Dodge are 95% passenger drop.
most of the Ford units use a 6 bolt round pattern and should have a 31 spline input, while most Chevy and Dodges use the figure 8 pattern and have multiple spline possibilities.

adapting 1 directly to the 42RLE could prove, fun. and would/could require an input change to the 205 TC.
best bet at this point might be to go ahead and use a doubler to make that connection, and the connection from the doubler to the 205 is market supported.
IIRC, the blackbox or ecobox claims to come out just an inch longer than the NP231. for a 42RLE this puts a Rubi Crawler into a nice place cause it'd replace the tail of the trans to stay short and can be fit to adapt the 205, i'd think..

With the rubi crawler why run a 205? It would be a step backwards from a 231 gearing wise. The 205 is 1.96-1. There was a 3-1 LoMax set be he hasn’t made any in quite awhile. You might be able to save a few inches length wise and twin sticks would be the only upside.

 

[someguysjeep]

With the rubi crawler why run a 205? It would be a step backwards from a 231 gearing wise. The 205 is 1.96-1. There was a 3-1 LoMax set be he hasn’t made any in quite awhile. You might be able to save a few inches length wise and twin sticks would be the only upside.

all this for me is to gain front axle independence.
the gearing ends up the same as 231/205. 1:1. the 205 gives me that 1.96:1. the RC gives me my 2.72:1 back, and they double me up at 5.33:1. the RC on the 231 is a 3spd, this gives me 4 that aren't stacked so tight to be unused. since the RC replaces the tail on the 42RLE i'm basically swapping the length of the 231 for the length of the 205.

and if the 205 could get any wind under it's wings maybe they'd do a run of those low max gears.

i'm talkin out loud kickin ideas right now, IDK if this crap will even work for me yet.

 

[Gollywomper]

Gear selection is why I like a manual. I can choose 1st,2nd or 3rd and change my crawl speed.

 

[mrblaine]

Gear selection is why I like a manual. I can choose 1st,2nd or 3rd and change my crawl speed.

I change all that with how much throttle I use.

 

[Wildman]

Gear selection is why I like a manual. I can choose 1st,2nd or 3rd and change my crawl speed.

You can do the same with a automatic if you have a manual value body.

With mine I can lock it in 1st or 2nd gear and it's there. Won't shift out of those gears.
The one thing I like more about a automatic is no more 3 footing it.

 

[Gollywomper]

You can do the same with a automatic if you have a manual value body.

With mine I can lock it in 1st or 2nd gear and it's there. Won't shift out of those gears.
The one thing I like more about a automatic is no more 3 footing it.

Yes there have been times I wish I had 3 legs or 2 pedals. Lol

 

[IPerkWVU]

The worst!

Especially off camber... facing up hill.. start and stop in 1st.

@jesseshoots if in 4low, before you start the engine, put it in first gear, foot on the brake, and turn it on. It will start and you move forward

 

[jesseshoots]

@jesseshoots if in 4low, before you start the engine, put it in first gear, foot on the brake, and turn it on. It will start and you move forward

Even without the clutch pedal depressed?

 

[IPerkWVU]

Even without the clutch pedal depressed?

Yep, foot off the clutch. starter will kick it into gear, at least with my rubicon. Use it all the time on the trail.

 

[SkylinesSuck]

Even without the clutch pedal depressed?

Yep, foot off the clutch. starter will kick it into gear, at least with my rubicon. Use it all the time on the trail.

You guys just said two different things.

If you have the clutch safety bypass fuse pulled or installed (don't remember which way) you can start it with out your foot on the clutch. If you do that with it in gear it'll take off. Not something you want to always have enabled if you let your kids play around in the Jeep while you work on it!!

 

[joelachr]

Even without the clutch pedal depressed?

I think Rubicons function that way in 4LO. However, all TJs should have a fuse behind the glovebox that enables/disables the clutch safety switch.