NP / NV 231 strength ??

Voodoo 6

Voodoo 6

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Joined
Dec 1, 2006
Location
Mooresville, NC
Any one know the strength of a standard Jeep 231 compared to a 231 HD ? etc..

I know military Humvee's had a HD version.
 
HUMVEE's never had a 231; maybe a 241 though.

The 231HD is an almost entirely different animal from the 231. Upgraded 5 planetary input (from 3), 1.25" chain and gears (instead of 7/8 or 1") and a thicker case...I'm sure there's more too, that was just on the top of my head
 
GM vehicles have the np241, its a little bigger and beefier, with two input spline versions 27 spline in half tons 32 spline in 3/4 1 tons otherwise the same just different spline inputs. You can take a np231 input and swap it in thou for a bolt in replacement in a jeep :driver:

Strengthwise on the 231, and 241, I honestly haven't seen too many of em broken, usually if they do its because of a cracked housing since they are aluminum, but never really seen many internal failure other then when they were ran dry (guilty :shaking: )
 
hmmm

I remember crawling under a humvee while in the field at Ft. Bragg. It did in deed have a 231 HD. thats what was on the tag. Now that has been a few years, so maybe they don't use them anymore.
 
but if you had your choice which would you have??? i've got a 231 but have been thinking of getting something beefier....
 
I think civvie Hummers mostly have 242HD's.

The 231HD looks like a pretty pimp little t-case! I'd love to have one for my GF's XJ! IIRC the difference between a standard 231 and a 231HD is HD had beefier bearings and planetaries, a beefier output shaft, and a wider, stronger chain.
 
BBradley said:
I remember crawling under a humvee while in the field at Ft. Bragg. It did in deed have a 231 HD. thats what was on the tag. Now that has been a few years, so maybe they don't use them anymore.
Click to expand...
HMMWV's used the NP218 and now the NP242. Both of which are 'special' versions made for AM General
 
Perhaps the one you saw at Bragg was 'retro-fitted'?

Those aluminum cases are pretty strong, and the 2.72 reduction is awesome compared to my 1.96 all-steel-heavy-mo-fo NP205.

You just need to make 100% sure your driveshafts are the correct length (so they don't push into your t-case on compression) and they'll be alright
 
Thanks for all the input

Here is what it boils down to. I have a 99 WJ with a 247 t-case. ( full time ) I want to replace it with something bullet proof. That I can get cheap. and that I have a two wheel drive option. I was thinking a 231 but wasn't sure about it standing up to my V-8 and any mods that will come later.I know others have used a 231HD with no problems.

Not to mention with gas prices. It will save me some bucks to have a 2 wheel drive option. I drive alot for work. In just a little over a month it will save me $ 400 in gas.
 
CrashKnott said:
Perhaps the one you saw at Bragg was 'retro-fitted'?

Those aluminum cases are pretty strong, and the 2.72 reduction is awesome compared to my 1.96 all-steel-heavy-mo-fo NP205.

You just need to make 100% sure your driveshafts are the correct length (so they don't push into your t-case on compression) and they'll be alright
Click to expand...


x2 on the driveshaft length I've seen a few break the housing because of bottoming out.

But the cast iron housing on the np205 is pretty sweet, its like its own skidplate :driver:
 
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