trans.,transfer case, Diff.,Fluid change questions

[ike]

I have a few manuals for my 76 Blazer and am trying to find out what type of fluids to use for servicing.

For the auto Transmission I see Dextron...but what filter do I use.? Do I have a 400 of 350..How can I tell..?

For the Diff.'s 90w but do I use the additive ? Do I have a Standard Diff. or "Posi/Power-lok"..?

And the the transfer case.Do I have a conventional or Full time..? I think a kit has been installed does that affect the type of fluid I use or amount?
Says a convent. takes 90w to the plug but a full time takes 10w-40 1/2' below the plug...??

Thanks for the help......>>>>>>Soon to b member<<<<If anything I owe

 

[k20]

a th350 pan is a square w/ the corner cut off, the th400 looks vaguely like illinois. Look in the glovebox to see if you have G80 as an rpo code, if you do, then you have a govlock, but, when you pop the cover, if it looks funky, then you have the gov-lock, if it looks like a regular diff, dont worry w/ additive.

As for the transfer case, I believe you have an np203, which takes motor oil. If you have an np205, then it takes gear oil. If you know what your shift pattern is, could probably tell what t-case you have.

if you have the kit installed, I assume you mean the part time kit, in which case you have the 203, and that takes motor oil.

 

[destinbeachman]

transfer case id

If the rear cap on the front output shaft section of your case has an aluminum plate that says Milemarker on it then you have a part-time kit.20w50 is what I use in mine with good results.Not so good as a 203/205 combo which Santa is bringing but i haven't broken it yet.If you don't use it in 4wd much then once every week put it into 4 hi and drive it down a dirt road or whatever for a mile or so to get some of that oil splashed around.That's why it uses such a lightweight oil.