Trail_Krawler & Trail_Willys

In the middle of upgrading the the NP231. The input shaft has to be replaced to mate up to the 6L80 transmission correctly, that's really just a R&R. In an effort to keep driveline angles to a minimum I replaced the current SYE with a super short SYE from Terraflex. This will allow my driveshaft to be about 3" longer. During the disassembly I dropped the debris magnet on the ground and it shattered... so Now I'm waiting for a replacement. Sucks when a relatively easy project gets sidelined by something like a broken magnet. I took the opportunity to clean up the case and paint it "cast iron" gray.

PXL_20220528_154709711.jpg
 
  • Like
Reactions: JMT, Woodrow, NashvilleTJ and 5 others
kmas0n said:
In the middle of upgrading the the NP231. The input shaft has to be replaced to mate up to the 6L80 transmission correctly, that's really just a R&R. In an effort to keep driveline angles to a minimum I replaced the current SYE with a super short SYE from Terraflex. This will allow my driveshaft to be about 3" longer. During the disassembly I dropped the debris magnet on the ground and it shattered... so Now I'm waiting for a replacement. Sucks when a relatively easy project gets sidelined by something like a broken magnet. I took the opportunity to clean up the case and paint it "cast iron" gray.

View attachment 333363
Click to expand...
I like the paint! Looks good! Hurry up and finish by fall so we can wheel it!
 
starkey480 said:
I like the paint! Looks good! Hurry up and finish by fall so we can wheel it!
Click to expand...
Just another year or three!
I didn't get to touch it for about two months during spring break... business was good. I'm easing back into it. Piecing together steering and front suspension now.
 
  • Like
Reactions: lBasket
kmas0n said:
In the middle of upgrading the the NP231. The input shaft has to be replaced to mate up to the 6L80 transmission correctly, that's really just a R&R. In an effort to keep driveline angles to a minimum I replaced the current SYE with a super short SYE from Terraflex. This will allow my driveshaft to be about 3" longer. During the disassembly I dropped the debris magnet on the ground and it shattered... so Now I'm waiting for a replacement. Sucks when a relatively easy project gets sidelined by something like a broken magnet. I took the opportunity to clean up the case and paint it "cast iron" gray.

View attachment 333363
Click to expand...

Do you have any concerns about the 231 holding up to the extra power? I'm doing a similar engine/trans swap and am debating between the 231 and standard JK 241 or 241c. I know you can do a 6 gear planetary and wide chain for the 231, but the case then becomes the weak link.
 
fixmysix said:
Do you have any concerns about the 231 holding up to the extra power? I'm doing a similar engine/trans swap and am debating between the 231 and standard JK 241 or 241c. I know you can do a 6 gear planetary and wide chain for the 231, but the case then becomes the weak link.
Click to expand...

The 3 planetary is rated for something like 600ftlb of torque. So no issues there unless you like bouncing up rocks. The case only breaks for 2 reasons... Lack of front drive shaft maintenance or improper front drive shaft length. Neither will be an issue for me. I may eventually upgrade too an Atlas just for the versatility.
 
  • Like
Reactions: Jamison C and MichaelGH
If powered by a few you decide to ‘race’ at stop light in Jan, lose control on snow pack, and hit pole it does test the limits of a np231. But may well be that front driveshaft was simply to long for that given application ;)
 
kmas0n said:
The 3 planetary is rated for something like 600ftlb of torque. So no issues there unless you like bouncing up rocks. The case only breaks for 2 reasons... Lack of front drive shaft maintenance or improper front drive shaft length. Neither will be an issue for me. I may eventually upgrade too an Atlas just for the versatility.
Click to expand...

Awesome. Thank you. From what I've read some people beat them for years with no issue, and others keep breaking them. Seems like the people breaking them have a drive shaft issue. Hopefully you could show which input shaft, adapter and clocking ring you use when that time comes. I have an idea, but it would be great to see how it all comes together. Sweet build by the way. Read the whole thing over the last couple days.
 
fixmysix said:
Awesome. Thank you. From what I've read some people beat them for years with no issue, and others keep breaking them. Seems like the people breaking them have a drive shaft issue. Hopefully you could show which input shaft, adapter and clocking ring you use when that time comes. I have an idea, but it would be great to see how it all comes together. Sweet build by the way. Read the whole thing over the last couple days.
Click to expand...

Thanks!
 
kmas0n said:
The 3 planetary is rated for something like 600ftlb of torque. So no issues there unless you like bouncing up rocks. The case only breaks for 2 reasons... Lack of front drive shaft maintenance or improper front drive shaft length. Neither will be an issue for me. I may eventually upgrade too an Atlas just for the versatility.
Click to expand...
The transfercase will see way more than 600 ft/lb. I could see a 231 failing behind a 6l80 with a 4.03 first gear and a little over 300 lb/ft of torque not counting torque multiplication by the torque converter.

https://www.motortrend.com/how-to/ccrp-0310-torque-converters/
 
  • Like
Reactions: NashvilleTJ and Apparition
From what I’ve seen they tend to break when the chain gets stretched and not replaced and then get beat on… but I would probably still be thinking about an atlas at some point in your case(pun intended)
 
  • Like
  • Haha
Reactions: NashvilleTJ, Apparition and kmas0n
kmas0n said:
guess I'll start saving for an atlas
Click to expand...

https://www.novak-adapt.com/knowledge/transfer-cases/np231

So Novak's website says that the HD version (6 gear planetary, SYE and possibly wide chain) will handle up to 2,900ft/lbs, and the standard is 1600-1900. I just called Novak to see what the tech department would say and he said no issues until about 500ft/lbs at the crank with the 6L80. It all looks good on paper, I was just looking for some real world experience. I wonder if any of the stroker or supercharged guys have had any issues?
 
  • Like
Reactions: Wildman, Apparition, Brianj5600 and 1 other person
Top Bottom
Back