Front half shaft stuck in wheel hub--any ideas?

I'm rebuilding the front end on my 2000 4x4 F150, and I'm having trouble separating one of the half shafts from the wheel hub. Basically, I'm looking at this (not my truck, just a random internet pic of the same model):

It's a pretty similar arrangement to the rear of my Thunderbird, so I thought I knew what to expect. One side was easy--no force at all needed to separate the hub from the half shaft. But the driver side is stuck. I've tried penetrating oil, 2- and 3-jaw pullers (pull on the hub, push on the half shaft, works great on T-Birds), a 4-pound sledgehammer on the tip of the axle shaft, and some moderate tapping on the portion of the axle that's just inboard of the spindle. There's absolutely no room to get a pry bar between the spindle and the half shaft. So far, no luck. 

Haven't tried heat yet because I'm not sure if there are any seals in there I might damage. I'd really prefer not to have to remove the front spindle, hub and half shaft as an assembly to deal with this. If there's any way to make this work with the parts still in the truck, that would be my preference.

Any ideas I haven't thought of yet? Thanks.

Try the super penetrating oil:  1/2 ATF and 1/2 acetone.  Mix it up, dump it all in there and around it.  Then whap it with the BFH and put the pullers back on it.

Try your hammer again. Hit the end of the axle hard. Rotate axel 90 degrees. Repeat until it releases. It sounds like it is gauled in there. If a hammer wolnt get it out, then you will be removing it as an assembly. 

Your other option is to use an air hammer if you dont care about hurting the end of the axel. If you have an air hammer and a blunt end, I would go this route. 

Make sure you've got it set up where you can hit it hard enough without damaging the end of the axle (assuming you're trying to reuse it). That would mean either making sure the end of the axle isn't threaded so you can just bash it directly, or running the nut a little above flush with the end and bashing the nut, or if its a stake nut or castellated nut or other kind of nut where one end is easily distorted, flipping the nut over and bashing the flat backside. 

If you cant get it with bashing, put the puller back on it, load it up, and then bash the end of the puller.

If that doesn't work, there are pullers specifically for this that pull on the studs instead of regular jaw pullers.

Slide hammer on the hub is another option.  Get the big one. :)

For a heroic effort, see this video:  https://www.youtube.com/watch?v=SFScIV92ODE

I had the same problem with a fron axle on my old Integra. Heat, penetrant, BFH, etc did nothing.

I ended up removing the whole knuckle and axle and bringing it to a machine shop to press out.

The next day the guy gave it back and didn't charge me a thing because his 100 ton press couldn't separate it. He said the whole machine was flexing and the axle still wouldn't budge. I ended up having to get a new knuckle from the junkyard. 

Thanks for the responses.

The more I think about this, I don't think I can remove the hub, axle and spindle as an assembly if it comes to that. I think the axle is in the way of the lower ball joint, preventing me from removing the spindle from the lower A-arm.

Air hammer or press at this point.

In reply to Will :

If it's anything like the Jeep front ends, you can probably pull the hub and axle off of the knuckle with them still attached and the knuckle still attached to the truck.  The axle likely fits through the hole in the knuckle. 

For a heroic effort, see this video:  https://www.youtube.com/watch?v=SFScIV92ODE

That was a cool video but it's also a nightmare scenario for the average person. LOL 

Thanks to everyone for your suggestions. This morning I ran down to Harbor Freight and used their 25% coupon on a 12-ton hydraulic gear puller. That plus the 4-pound sledge against the hub finally did the trick, but it still took about everything that puller had.

Got the lower ball joint out without too much fuss after that, so disassembly is done. Now for reassembly.

I didn't know they sold that and now i want one. They did text me a 25% single item coupon for July 4th only. Hmm.