'87 Montero - 4WD not functioning.
 

I bought my pristine '87 Montero during the summer, when I couldn't really check out the 4WD function - but everything seemed to work. Fast forward to now, when we finally have snow on the ground, and no 4WD!

The transfer case shifts into 4h and both the front auto hub lock and 4WD lights go on (no flashing - both solid.) The trouble is that there is still no traction from the front wheels at all (in the snow, come to a full stop and intentionally dump the clutch momentarily - back wheels spin, fronts stay stationary.)

I have the FSM, but I'm not sure how to troubleshoot this; any ideas?

get out and manually lock the front hubs.

Cute - though I probably asked for it by not explicitly pointing out that it has auto hubs.

do you try driving it in 4h, about 20 yards, give it time to engage those auto hubs?

Yes, of course.

hmm. fluid in the t/fer case? half shafts fitted in the front? make any weird noises going into 4?
i assume it's a lever to engage the 4, does it feel like it's pushing cogs?

jack all 4 wheels up, and get under it when it's idling in 4 and see whats spinning...

Hi, I just looked at the fsm. It appears that the lights are nothing more that "idiot lights". They don't give any indication that anything is engaging mechanically. Otherwise there would be some type of interlock switches within the hubs. That being said, the whole operation of the hubs going from unlocked to locked is purely mechanical. I suspect that it may be a lack of lubrication in your hubs. You mentioned that its cold out. Perhaps there is moisture in the hubs causing the mechanism to freeze? Freezing moisture and/or lack of lubrication may be the issue. Hope this helps. Good luck!