Front axle / free run. Hub noise & 'clunk' '08 zd30

[Col.T]

Never rains but it pours, doesn't it.
Got an engine error message ongoing and now this.
Down a slight decline, in 3rd. or 4th., virtually no throttle and suddenly a noise exactly like a kid holding a stick on the spokes of his bike. Slow to a stop and get one or two sudden thump sounds and quite heavy jerks / shudders. Can't tell if gently braking after the noise starts is directly invloved in the clunking.
This is the second time in about 500 plus K's..with perfect running between.
I'm sure it's coming from the offside front wheel assembly (I think). Perhaps I'm dreaming but it seems as if the front wheel drive hub is trying to slip into 4wd but I can't see how that could be. I've had it off but it seems to be in order.
Can't see it being any thing to do with the ABS sensor but I just can't work it out.

Any help greatly appreciated
Col.

[Morton]

its your auto hubs, they are trying to engage or one of them is at least, the noise is like you are dragging a coathanger on the ground next to you, as you are nearly stopped it with clunk enough to shudder your truck, sometimes going in reverse for 20m will fix the issue, other wise lock it with a wheelbrace in 4L & drive on grass or dirt, back & forth a few times, unlock, put it in 2H, reverse it 20m, usually enough to confuse it back into position, sounds silly but it works, water crossings may have eroded the grease, pack grease into them but mark the hub first so it goes back into the same location & on the same side, if it continues replace it, if it is doing it all the time, take one off, slap the bearing full of grease & drive it around for a couple of kms no more, if it continues you have taken the wrong one off but you know which one it is now, or simply replace both with secondhand or new, they often fail as a result of not locking the hubs offroad or water mixed with the grease

[WillO]

I have just begun experiencing this exact same problem...Will give Morton's suggestion a try tomorrow. fingers crossed!