Tcase lube question? 76 blazer full time 4x4

The NP 203 requires straight 30 non detergent motor oil (you can use

20w in winter if you want). I would not use multi viscosity detergent oil as it tends to foam in gear cases. Also the Tcase and tranny are seperated by a set of oil seals and the chance of Tcase oil getting in to tranny is very, very low. You have tranny issues developing as well if you are finding metal in it. When you pull Tcase check to see if input shaft seal is intact. Generally 203?s are pretty sturdy and if they are properly oiled and serviced they last a long time but big tires with tall gears and no maintaince can greatly shorten their lifespan. Also some part time conversion kits for the 203 do not lube case bearing properly in 2wd and can shorten case life as well.

Thanks for your help snoman. I think it will be a few days before we change the tcase. But I will use your suggestions.