What's the proper lube?

[coburja]

For you guys "in the know", I was hoping you could help. What is the proper lube for the front and rear diff and the transfer case for a 1997 GMC 3/4 Ton truck?

 

[OHMS LAW]

i think its gear lube 80w90

 

[383 240z]

ATF in the t-case

 

[Gary S]

RTFM
Your owner's manual in the glovebox should have the information.

 

[Altec]

80W-90 in everything but a Dana rear. ATF in the Transfer case.

 

[Kevin C]

Hypoid Gear lube ( axles) should have a GL-5 rating.

 

[bigdav160]

Use synthetic gear lube, your trucks side bearings will thank you

Is this a push button transfer case? Does it have an "auto 4x4" position? That transfer case uses a special fluid only available from GM.

 

[stormin]

ky of course

 

[Ulrick]

Its regular 80W90 GL5 in the axels, ecxept the 11" Dana takes 75W90 Synthetic.
Transfer case ATF dexron III

 

[acidise]

Got a 98 1 ton. Went through the same thing. Use synthetic 75 w 90 in the diffs. atf in the xfer case if it's a floor shift. Auto push button = fancy gm only oil. Same as above. Check owners manual cuz some diffs need "friction modifiers" additive. Usually only if it's a limited slip/ posi trac. Open diffs are plain, synthetic 75 90.

 

[wornoutoldman]

Check here for lube specs and quantity:

http://www.amsoil.com/mygarage/vehiclelookup.aspx?url2=1997+CHEVROLET

 

[lotsoftools]

Got a 98 1 ton. Went through the same thing. Use synthetic 75 w 90 in the diffs. atf in the xfer case if it's a floor shift. Auto push button = fancy gm only oil. Same as above. Check owners manual cuz some diffs need "friction modifiers" additive. Usually only if it's a limited slip/ posi trac. Open diffs are plain, synthetic 75 90.

It is the option G80 that needs the friction modifier

 

[Will67]

Astrolglide?