Just posting this to share the knowledge. I took the K20 to the beach the other day and while going up a one way deep sandy track heard an almighty crack and all foward motion ceased. Played around with it for a while and just ended up digging the back in. The front diff wasn't putting power to the ground...I figured it was a hub. Got snatched out by a SWB Mistubishi Pajero (lucky it was a downhill stretch), a humbling experience. After inspection found that the hubs (8 lug D44 old spicers) main retaining circlip was damaged and nothing was cominig apart out in the boonies (30 miles worth of beach, then 20 miles dirt road back to civilisation). But after more checking it seemed there was no need, everything was locked up....when turned by hand all the shafts did what they were supposed to. However once underway the truck started to sink on any dry sand patches....oh well down to the tide line (hard sand) and plenty of washing at home. To cut a long story short I finally got off the beach after the 4x4 gods smiled down upon me and told the hubs to re-engage at several crucial moments. The Minister for Home Affairs (other half) was not happy. It turned out I was very very lucky...the locking collar on the spindle had loosend, allowing for some freeplay on the spindle. This caused the erratic behaviour of the hub, engaging and disengaging at will. Thinking it was just a hub I drove 60 miles back to home. I should have thought about it more on the beach....if the hub was ok then something else had to be wrong. Could have been a bad day on the blactop if everything had let go. BTW the truck drove fine going home, the wheel was sloppy but not as bad as it should have been, some retaining parts on the hub are trash and the guts of the hub are in good condition. The bearings were'nt trashed and the inner seals spring collar was toast. There was evidence of heat around the rear bearing and where the outer locking collar rubbed the back of the hub guts. The outside of the locking hub could freely rotate too. Finding that made me think that it was a compounded problem. (oh yeah nobody touches the truck but me...anything goes wrong with it and its down to me alone) So if your manual hubs start acting like they have a mind of their own, have a close look at everything else.