1990 4Runner 4WD Problem

[Vegas Z71]

OK all you Toy guys...my sister's b/f is borrowing my parents old 1990 4-Runner (he is in a Suburban now ). He was going to pick her up at the airport during a snowstorm in Reno...but could not get the 4WD to engage. He can move the shifter into 4H and 4L, but the front wheels do not engage...the rear wheels continue to spin, and the 4WD indicator light on the instrument panel does not come on.

Any ideas as to what he may be doing wrong? They claim to have tried putting it in Neutral, etc. Thanks.

Vegas Z71

[Sark]

Did you ever figure this out. We are having the exact same problem in Reno.

Thanks

[Brian R.]

Probably need to change the front diff. lub. Put in 75W90 gear oil. If that doesn't solve the problem, probably the ADD actuator system.