Auto hubs/Drive flanges?

[bluecrew]

On a buddies 1978.5 K30 SRW I noticed it had smooth covers where you would normally go to lock the hubs.  I've heard those are the auto locking hubs/drive flanges that GM offered back then.  The current (and original) owner says he ordered it that way.  I also searched and can only find that they put those on trucks with NP203's.  I could of sworn the transfer case was a NP205.  Is this possible?  Did they offer the auto hubs on trucks with 205's? 

Has anybody ran auto hubs?  I would think they would be better as less moving parts, less to go wrong... Are the auto hubs comparable to real locking hubs (Warn)? 

[ncguy89]

i have seen newer blazers like 87 and 88 models with auto hubs but i have seen them mostly on np203's but im not sure so i will let someone else chime in on that. if it is a np203 it will have 4 hi, 4hi loc, 4low etc. if it is a np205 it will have 2 hi ,4hi,4low ect. on the tcase shifter. you can post a picture of the transfer case and one of us can tell you which tcase you have. me personally i dont like auto hubs because it is locked in all the time will cause front tire chatter when turning sharp and will wear out u joints quicker. i think manual hubs are a better setup but to each there own. as far as been comparable i would say no comparison but not sure what your asking here. like strength or durability or what?

[Sartobuilt]

If it definatially has a 205. I think what you have is a truck that was ordered with out locking hubs. Under the dust cap is a drive cog. Installing a set of locking hubs is not a problem. Is it a Dana 60 axle?

[bluecrew]

It is a Dana 60.  My buddy's uncle (original owner) ordered it from GM with the auto hubs.  I have had several 205's and a few 203's in my day, and I swear it's a 205...  But, I am a guy, and some would say guys can be wrong...  the truck is located about 45 minutes away from me, so I will have to wait until the weekend to shoot out there.  I wonder if the drive flanges would be as strong as regular hubs.  In the mud.  With bigger tires.   With the 205, the front shaft would be stationary until put into 4x4.  I believe the 203 is always spinning the front shaft.  I have since sold off my mud trucks, but will be building another one sooner or later.  I wonder if this would be a simple, upgrade.  I see truck pullers use drive flanges.  With a 205, you can have the front hubs locked and still cruise around on pavement in 2 wd with the front shaft stationary.  Hubs have several parts to fail.  Simplicity is king. 

Thoughts?

[Cabcorner]

                        Those are not auto locking hubs . Those hubs are always engaged and only came with 203 full time transfer cases .

[Sartobuilt]

Yes those drive hubs are valuable to the pullers and serious mudders. Those drive hubs are alot stronger than a locking hub. I have never seen auto hubs on a Dana 60. 

[thirsty]

They are tough. I like being able to unlock the hubs though. I broke a universal once while i had hub gears instead of hubs. Had to leave it and go get a hub so I didn't do anymore damage.

[bluecrew]

I would only run them on a 205 equipped rig, but I do like the idea of them.  I do worry about it no longer being the weakest link.  Hubs usually break first vs. axle shafts...  Maybe on my next wheeler build, I might try some.  Problem is, they are becoming quite rare.  From what I gather, only offered from 1977 to 1979.