Transfer case oil change

[Stormin]

I'm trying to change the oil in my transfer case. I believe it is a 203. I have the 2wd low range, does that mean it has to be a 203? I know it's not a 205 but I don't know what the 208 or 241 look like. Anyways, I need to know what type of oil to use in it. I heard that they use motor oil but the oil that came out of it looked (and smelled) an awful lot like 90w gear oil. Also, how often should the oil be changed?

 

[sweetk30]

203 and 205 cast iron. and 208and up are aluminum. 203 full time 4x4. all others part time. what year truck and or kind of case to id it for ya.

 

[Stormin]

It's a 77 blazer 350/th350 and I believe it is a 203. Looks like one anyways. But it is not full time 4wd. Just really need to know what sort of oil to put back in it.

 

[divorced]

Probably a 203. I think a 205 has a drain plug, and a 203 doesn't.

A local 4x4 shop told me to use 10W40 in mine when I had it.

 

[bugspray]

Does it look like this? http://community.webshots.com/photo/183256651/183257088kAJBFL
No oil drain plug? This is the 203. If so, undo the bottom bolt, drain, and refill with whatever weight you are running in your truck. I use to think I should use 90w gear oil, but learned better through this site.

 

[Wes Harden]

I'm running 80-90wt gear lube and 30 to 40% lucas in my np205 and my dana 21's. been thinking about running 100% hd lucas in them anybody else do this ?
Wes

 

[pauly383]

If you have 2wd low range , then you would have two shifters , one for hi/low and one for front/rear , custom , not factory , and can't be done to a 208 or 241 at all since its got one lever like an auto tranny and does everything internally in a way you couldn't do it with two shifters .

Or it is a converted np203 , to part time .

We all technically have 2wd low if we don't lock our front hubs with anything else

 

[google]

Hmm, maby now i'll go outside and see what transfer case I have too.

 

[google]

I have a 208 stamped 1981. Is that a good thing or a bad thing?

 

[mudslinger99]

As far as fluids in transfer cases is as follows

203 = 10-30 0r 10-40 oil

205= 80-90 weight oil

208 = atf tranny fluid

 

[Stormin]

Thanks for all the info guys. I think I'm finally starting to get a grasp on the differences between all these transfer cases. One more question though. How often should the oil in the TC be changed?