4x4 not working, with manual hubs

Sorry to sound completely useless but it’s baffling me. The transfer box I assume still works as low box still engages. I don’t think it’s the diff as I can’t spin the front prop when in 4wd and I can when in 2. 
I have manual hubs too, recently I rebuilt the axles but I took these off in the two parts. Didn’t actually interfere with the internals of them so can’t see where I would’ve got that wrong. No unusual noises either. 
Any ideas please before I start crawling round in the wet outside, Cheers

Is manual lockers, manual hubs?

The hubs might be sticking, you could take one off and see if the shaft locks in place in 4WD? If it doesn’t it suggests the diff?

If they are still vacuum hubs then you might have a blockage in a vac line or again the hubs are sticking.

Robin

Forgot to mention the front prop is locked by the transfer box, rear prop and rear wheels when in 4wd.

Cheers, yes I meant manual hubs sorry. And I will try taking them off and checking. Thankyou

Assuming you have AVM ones when you twist them in and then get back into the car and engage 4x4 and pull forward within a couple of rotation of the wheels you should hear a definite click from each one as the springs engage the drive members. This will obviously be clearer with a window open. It is possible to check by lifting one front wheel while in 4x4 and spinning it, with the hub in it shouldn't rotate or if it does it's something deeper.

wrote:

Sorry to sound completely useless but it’s baffling me. The transfer box I assume still works as low box still engages. I don’t think it’s the diff as I can’t spin the front prop when in 4wd and I can when in 2. 
I have manual hubs too, recently I rebuilt the axles but I took these off in the two parts. Didn’t actually interfere with the internals of them so can’t see where I would’ve got that wrong. No unusual noises either. 
Any ideas please before I start crawling round in the wet outside, Cheers

What makes you think it's not working?  What are the symptoms?

Engage the hubs with the transfer in 2wd, and try and turn the front propshaft.

If you can't turn it round and round the hubs are working and you will have drive to the front axle in 4wd if the transfer box is working*

If you can turn it round and round then one of

One or both hubs aren't engaging
You have a broken CV joint
You have a snapped half shaft (usually the short one breaks before the long one)
The diff is broken, e.g the bolts holding the crownwheel have sheared

*if the front axle all checks out disengage the hubs and put it in 4wd. If you can turn the front prop round and round the transfer box isn't engaging 4wd.