79 GMC K25 hub help

[hatzie]

If you look at the diagram for the K30 on Page 316 it's closer to what you have than the K20. Neither show those aftermarket Dualmatic hub locks tho.

You took out the wire retaining ring at #9 and the snap ring off the axle stub. The innards should slide out.
I bet you have an O-Ring catching.

[Nontwisty396]

I have a nephew looking at it with me right now for an extra set of eyes. He's a tinkerer like me and we've been discussing upcoming projects we both have. He read your post and looked again at the diagrams and we're both stumped. Both sides will slide about an 1/8" and then stop. They don't jam up, you can still rock them. Both sides act like there's another clip inside somewhere that I haven't located yet.
My next thought is to do a little more cleaning on the area where clip #9 sits, along with the outside edges of the alloy part to see if somehow something is catching. I can't grip the inner gear to pull on it, so I'll rig something up to pull on the alloy part to avoid breaking it.
I know I'm gonna look back at this soon and say "wow, that's all it was, and so obvious"...

[hatzie]

This is a set of Mile Marker Selectro 11001 hub locks... Close enough to the same as the Mile Marker Dualmatic Hub locks. For the 10 bolt style front hubs.
http://milemarker.com/wp-content/upl...ODEL-11001.pdf

Once #9 wire ring and the ring on the end of the axle stub is removed they should come out as a cartridge.
My guess is the o-ring is hanging in the wire ring slot. Maybe re-install the actuator and pull on it to remove the assembly.

Pictures are from this auction. http://www.ebay.com/itm/Selectro-110...-/172151852416

[Nontwisty396]

I looked at the pics you posted and didn't read your message at first, and that's exactly what I was thinking! It helps so much being able to see the part to have a better idea of how it works.
So there's an inner o-ring I didn't know was there, and I bet you're right that it's probably hanging up in the groove.
Looks like I'm gonna give er a try and get back with y'all in a few.
Thank you for all your help with this!

[Nontwisty396]

Well...I tried...but, the alloy part the hub handle attaches to is now broken to the point of not being usable. And the thing didn't budge past where it had before. And the axle moves freely in and out, so I know it's not hanging up there. So now I'll try a little more sanding and filing, now that I see how it fits together. I'm sure you're right and that inner o-ring is hanging up in the groove.
The good news is I had gotten to the point of being prepared to replace the hubs anyway.

[hatzie]

The Direct link to the Mile Marker PDF isn't working.
The end of sentence four agrees with us. Apparently they are worried about the o-ring not passing that groove.
MODEL-11001-2.pdf

You can likely separate the tie rod from the knuckle and the ball joints from the axle ears and drive the damaged hub lock out with the axle stub removed.

[Nontwisty396]

Yeah, that would appear to be the problem I'm having.
I'll explore a couple other options I've thought of, and I'll post results asap.
Thanks again for all your help. You seem to be able to find links I have not been able to find. And the manuals you've provided are a fantastic asset. Again, Thank You!
I'll have more in a couple of hours or so...

[hatzie]

I'm more and more happy mine had the Warn 9072 bolt on external hub locks rather than the 77 1/2 & later cartridges.

[Nontwisty396]

Yeah, I've been thinking of upgrading for a while now. This is a good time to take the old girl down for a bit. I have a spinal injury from a wreck and can't drive right now, so I'm currently building a mild 350 to breathe new life into her, replacing the old leaky tired 400. I'm considering just pulling the entire diff out and going completely thru it... I'm replacing the ball joints anyway, so why not do axle joints and all bearings and seals, and maybe even take it up to a limited slip?

Still working on getting the base out... It sure doesn't feel like an o-ring holding it, but that's about all it can be, going by the diagrams...

[Nontwisty396]

WooHoo!!!! Victory! There was a casualty in the battle, but that's to be expected. At least it was only the alloy base.
The o-ring is rock hard and crumbling. That explains why every time it got to the groove for the lock ring it would just stop. I had to keep rocking the base to knock chunks of o-ring loose, push it back in, clean the groove and lube with foaming silicone spray, and repeat. Each time more of the o-ring would work off, until finally enough was worn off to allow it to come out.
The inside of the assembly is clear of rust and dirt, which is surprising since the truck came from the Oregon coast, so it has it's share of damage from the salt air. And I'm sure at some point (or many) it saw the sand dunes...
But thanks to all of your help I have finally gotten one side apart!
Thank you!!!!

[83GMCK2500]

Excellent! Always good to read about success at the end of a thread.