Hello all,
Just wondering what is best to use here-Manual states Gl-5 OR Gl-4, but ive heard and read that GL-5 is definately not good for these transmissions...Is this factual?
Also, i live in a remote location; NAPA(that is actually Ashland/Valvoline?) is the only cheaper brand closely located.Their info on bottle states, "API services Gl-3,Gl-4,Gl-5" Is this safe to use in my w-56 and transfer case?
Oh, and BTW- it is "80w-85w-90"(dont know, why triple viscosity...?), how does this differ from
75w-90 called for in the manual? Is 80w-90(80w-85w-90) an acceptable substitute? I know everyone uses Redline mt-90 or Mobil synthetic, but i cant afford those at this time...Thanks AGAIN!-Pagan (22re140k4x4w56)

GL-5 is bad for the brass syncros in the tranny.
I used a standard GL-4 80/90 I got at NAPA. $4 or so per quart. I couldn't justify Redline at the time. No probs, all has been good.

Hey Staceman,
thanks for the reply. When did you get your Gl-4 NAPA? the only Gl-4 NAPA brand i saw had, like i stated, Gl-3,and Gl-5 ratings included. Was it synthetic? Is "Gl-4 only" oil synthetic only?I havent been able to find any standard gear oil classed in "Gl-4 only" category... Thanks again

Sta-Lube makes a GL-4 conventional gear oil, many auto parts stores carry that brand. GL-5 will not hurt the W56 tranny but it will not shift as well as with GL-4. You can use most anything in the transfer case:
- http://www.4crawler.com/4x4/index.shtml#SyntheticGearOil

4Crawler is correct. It was Sta-Lube brand I found on the shelf at NAPA. Other NAPA's didn't have it, but can get it. The NAPA I went to is the BIG parts depot for the Phoenix area.