i was doin some searchin on the web about my xj and i saw that they made two different transfer cases....there is an NP231 command trac-part time only(which is what i have)..and an NP242 selectrac with part/full time

might be a silly question but whats the difference between the two?

 

Good questions. The NP231 is the part time TC meaning you can only use it in slippery, loose gravel, snow conditions. Never on dry ground you'll kill you drive line. In the np231 you have 2hi( normal driving RwD), 4hi, n, and 4lo

The np242 is a full time TC. The is a 2hi, 4hi part time, 4hi full time(this can be driven on dry ground. All 4 wheel drive At different speeds so you won't get wheel hop), 4lo

 

I love having the NP242 in my XJ. I use 4-hi full time mode when driving on wet pavement on windy roads and I really feel like it helps the Jeep handle more securely. Not something everyone might need, but nice to have living in the Northwest where 9 months out of the year the Jeep lives on wet roads.

 

awesome stuff...thank you