i was changing the fluid in my transfer case the other day and my stepdad insist on looking things up in the ol haynes manuel either way im sure i read on here that my 94 sport has a 231 pt tcase which i learn on here is a select trac well the book said the the 231 was a command trac basicly everything i thought i knew from being on here was reversed so can someone clear this up for me

 

You misread or wherever you read that a 231 is a SelectTrac was incorrect.

 

I have a 1990 xj 4x4 and it's a command-trac labled NP231. The 231 is the command-trac.

 

yea, the 231 has part time only, which should be used if all 4 tires can spin freely, the 242 has 2 different 4wd settings, a part, and a full time. the full time allows you to turn lock to lock w/o issues like binding and wheel hop.

 

Yep.
Selec-trac = np242
Command-trac = np231

 

If you are still unsure look on the rear of your transfer case there should be a label telling you exactly what case you have. Also remember the 231 takes ATF not gear oil.

 

so does the 242.

full and part time 4wd= 242

part time only = 231

 

No wonder the guys confused...

 

Sorry i hadnt slept. he gets the idea now. lol