Hey everyone. I'm new here and looking forward to learning about my truck. Let's get right to it.

I changed the oil on my divorced NP203 transfer case. The manual said that it would take 9 quarts of oil, but it started flowing out of the fill hole after just 3 quarts. Is there an explanation why or did I do something wrong?

The truck is a 1976 F250 4x4 "Factory Highboy" Regular Cab. Let me know if I'm missing information to make things easier on you.

Thanks in advance.

 

Welcome to FTE. Did you drain it by taking the rear cover loose at the bottom?

NP203 Transfer Case Specs

NP203 Transfer Case

Good info here about using motor oil versus 90 weight gear oil and or trans fluid. New Process 203 Transfer Case Tech: Off-Road.com

NP203 New Process Transfer Case Diagrams and Information

 

Yes, I removed the three bolts on the bottom cover and let it drain for quite a while. I even made sure to drive around and warm up the oil so as to drain better. Only a couple of quarts came out.

I put 30w Royal Purple back in.

 

Which manual are you using? 9 quarts is pretty suspect to me. As long as you only got three quarts out, you should be good.

 

X2 on the amount out should make sense on how much goes back in. I Google researched and read 5 qts is the amount it takes, that advice was in a few places.

 

I'm using the Haynes Manual. That's kind of a bummer because I bought two cases of Royal Purple only to need 3 quarts out of 12. Oh well, such is life.

Thanks for the info guys. I'll just check the level again today to make sure and then stop worrying about it.

 

I would think that if the case or the bottles are not opened, you could return them? Craigslist as a back up option?