NP231J To Mod’ed NP231J Swap

I’m doing a  NP231J To Mod’ed NP231J Swap

Tools Needed:

Rachet Wrench
Sockets: 8mm 13mm, 14mm, 15mm, 19mm
14mm openend/boxend combo wrench
14mm racheting boxend wrench

this swap took me 6 hours

the Mod’ed NP231J Tcase has a SYE, Wide Chain, & Tera-2lo

tcase Fluid

the first thing I did was suport the trans

next I removed the bolts that hold the trans mount to the tcase skid (13mm)

dont for get to write things down and to use ziploc bags and a sharpie

next I removed all the bolts that hold the tcase skid on (19mm)

next I removed the bolds holding the front driveshaft to the output yoke on the tcase (8mm)

next i removed the bolts that hold the rear driveshaft to the input yoke on the axle (8mm)

next disconect the connectorsfor the 4wd light and the speedo

dont forget to remove the wireing harness clips

necx remove the shifting linkage

next remove the trans mount off the trans (15mm)

remove the breather line off the tcase

remove the nuts that hold the tcase to the trans (14mm)
the pic shows i used a rachet, but i had to use a 14mm combo wrench, would recomend the you go buy a racheting combo wrench

had to make a custom boxend wrench when the combo wrench was to long

after you remove all six, the case will slid off, rember it does wheigh 60lbs lol

tranny output shaft

getting ready to lift her into place

put the new case into 2hi and then slide the case on using the rear output yoke to alline the input shaft to the outout shaft of the trans

next its time to put every thing back

dont forget to use loctight, just incase

reinstall everything you just rmoved and the case is in!

i had to readdjust the shifting linkage… i just losend the adjustment bold (14mm) and shifted into 2 hi and retightened the bolt, and it worked for me

reinstall the tcase skid and your done

old tcase:

Leave a Reply