np231

[88swampedmj]

did they only come behind a ax15? or anything else? auto? .. i may get a ax15..but it doesnt have the t-case... i wanna get one from the yard.. but would a auto xj or somethin have one?

[rejeep]

yeah.. the auto ones will work also..

or you can buy mine... $250 shipped. :brows:

[Bounty Hunter]

They came behind most every jeep tranny '88 and newer, with a few exceptions. There are variations of the 231 input gear designed to fit various transmissions so keep an eye on that.

[88swampedmj]

so which one would be a straight bolt up?

[pingpong]

That depends on the spline count on the tranny.. it could be either 21 or 23, and some of them don't have the provision for the VD housing hook up as well

[88swampedmj]

well maybe ill get lucky and find a 4x4 tranny out in the "yard" but for now i could either get a BA10/5 for $150.. or wait to see if this ax15 doesnt get too expensive $150 is about my max... iam tryin to pay bills haha

 

i think ill just pick up that $150 BA10... and keep my eye out for a good deal on a ax15 and t-case then when i get the stuff ill upgrade.. but for now my tranny is dying haha

[Bounty Hunter]

You can swap out transfer case input shafts relatively easy, they run about $70 from Novak IIRC or cheaper used.

[Oizarod115]

231s came behind any engine/tranny from 1987+

from 87-90 they were 21 spline input

form 91+ they are 23 spline

 

(same spline counts go for the 242 case as well.)

 

for an AX15 you will need a 91+ case. i think after (94?) they were electric speedometer, not sure if that matters or not

 

BA10s are 21spline

[Bounty Hunter]

Good reference: www.novak-adapt.com/knowledge/np231.htm

[Pete M]

Good reference: www.novak-adapt.com/knowledge/np231.htm

 

Yeah, don't foget about the output shaft length too. There were seemingly random changes over the years.