Front axle hub identification please (pics)

[RTFM]

77' J20
I do not know what hubs these are and how is four wheel drive engaged (vacuum, mechanical)?

Please help me identify so I know what I have so I can prepare for this springs rebuild.

Thanks.

Front hub (both sides look the same) head on, drivers side.

http://i6.photobucket.com/albums/y237/we3/100_2774Medium.jpg

Front hub oblique

http://i6.photobucket.com/albums/y237/we3/100_2776Medium.jpg


Transfer case lever

http://i6.photobucket.com/albums/y237/we3/100_2779Medium.jpg

Trans and transfer case levers

http://i6.photobucket.com/albums/y237/we3/100_2781Medium.jpg


Rear hub oblique (both sides look the same) drivers side. In case for some reason it may be important.

http://i6.photobucket.com/albums/y237/we3/100_2777Medium.jpg

[KaiserMan]

Those are internally splined wheel hubs with drive flanges. Meaning the front axle is locked in all the time.
The chrome cover is just a dust cap.

You have a Dana 20 part time cast iron transfercase with mechanical linkage.

[Guru]

Man........You started on that kaiserman pocket dictionary yet.Dang your good.

[RTFM]

Yes thank you KaiserMaan this gives me a place to start to look up how they operate.
Is it as good (and reliable) as external manual locking hubs (better/worse/same?)

[KaiserMan]

Internal lockng hubs are supposed to be a bit stronger, but the wheel hub its self is a bit weaker (they are pretty thin). I think externals are stronger as long as you keep the bolts torqued properly.

But unless you are flogging this thing hard off road you will never notice a differance. What you have is plenty strong, and drive flanges are stronger then any selectable hub.

Everything from the steering knuckles out will be the same on a similar year GM 3/4 ton truck.

[Long&Low]

BTW, the rear axle is what is referred to as a full floater. The axle shafts does not support the weight of the vehicle like on a rear flanged axle design which is usually referred to as a semi-floater.

[RTFM]

Thank you guys, that helps a lot.

[fulsizjeep]

This must be some fleet or government purchased truck huh? Most the civilian models had manual hubs with D20. We had a 80 J20 at work for many years and it was an old Army purchase with a 727/208 combo and solid hubs. It was deceiving the first time I looked at it because I figured it had a 219.

[RTFM]

I think it may have been an Idaho Forrest service truck, our FS trucks are that color and all the pine needles and leaves I mucked out of her when I bought her made me think the same thing.

See my original post on buying it here:
http://www.ifsja.org/forums/vb/showthread.php?t=91098