I changed my oil yesterday. I use ramps to raise the front so I put it in 4 low, locked the rear axle and when I tried to go up the ramps, the back wheels spun in the dirt. I ended up having to take a bit of a run at it before it went up the ramps.
My question is this. Aren't all 4 wheels tied together at that point or is the front axle independent of the rear? I figured the front axle would pull it up the ramps regardless of what the rear did.
I'm just curious how the 4x4 system works......

 

When I put mine in 4 wheel drive I often have to drive a little a wait several seconds before it engages. I wonder if yours just didn’t engage?

 

As soon as you hear the t/c lock in you should be good to go. You may try to back up a few feet after your in 4low to make sure the hubs are locked in and try to ease up the ramps.

 

Did the dash light indicate it was in 4WD?

 

You really didn't need 4x4 at all for this.

 

The front diff is still open, so if one front wheel can slip, the other won't turn.

That depends entirely on the ramp.

 

I do need 4x4. It's a dirt driveway and the ramps are the old steel ramps. Pretty steep little ramps.

 

I had a couple times where i switched to 4 low when parked, but in drive and waited for the 4wd light, only for it to tell me i needed to shift to neutral for it to shift to 4low. Maybe thats what happened?

 

You didn't shift to 4 low correctly. Your manual explains how to do it in detail.

 

You're right. I was using it like my 98 f150, where you could just select 4L as long as stopped (at least thats what mine did lol) I just looked up the 2015 manual and it does indeed say "shift to neutral and select 4L" however, it is further down the page and towards the top of the page it simply says "at a speed less than 3mph" it only when you go further down to "shifting to or from 4L" that it says about putting it into neutral first. Honestly should be there right away lol