HUB LOK Problem on '67 K-10

[Justinjob]

I posted this earlier in the 4x4 section but no one has touched it, so I'm trying here too

HUB LOK problem on '67 K-10

Grrrr.....I'm having problems with the 4 wheel drive on my 67 K-10....when I engage the hubs (these are the original HUB LOK's that came on the front Dana 44 closed knuckle axle) to lock and put it in 4 hi, or 4 low and drive in forward gears, I get this nasty "pop" noise from the front axle about every revolution of the tires or so and the whole axle shudders. I'm kind of stuck on this one, I'm not sure what the problem i. When I disassembled the front knuckles, the upper and lower bearings (ball joints) are good-no play, and the u-joints are good too. The interlocking hub gears appear as if they could be slipping out of each other, there are a few little chew marks on the gear teeth-but they're still fine, none of them are broken or worn, and they mesh together well. I'm suspecting that maybe the multiple springs that push the gears together are worn and maybe do not have as much tension as they used to??? Then again, when I go to take it out of 4 wheel drive and unlock the hubs, they stick, they won't disengage-until of course I jack up the truck-then they come free easily....funny thing is last time I did this, as the front wheels started to come off of the ground-the passenger side wheel slipped and turned slightly as though there was tension, like it was under load, and that would explain why they won't disengage...but why would they be under load? (now that I think about it the truck may have been in gear, I'll have to try it again making sure that everything is in neutral) I'm also possibly suspecting that the drive ratios of the front and rear axles differ form a possible rear axle change someone may have done before I owned it. I'm not sure how to check this, I've ID'd the front axle (Dana 44's only have one ratio right?), but I still need to find out what the rear axle is, or should be and how to ID it. Anyone have any ideas?