Was wondering about the t case in my 90 Cherokee. To the best of my knowledge its a np231. When I shift into 4hi or 4lo, a light on the dash that reads "part time" comes on. Does my vehicle have the "full time" option at all?

 

No the np231 only has part time 4wd so 4hi and 4 low. The np242 tcase has 4lo 4hi and 4 full-time.

Hope that helps you out