Anyone know much about 4X4 auto hubs? (Have problem)

[92470]

I just took my 87' V10 out today and got a bit of a scare. It has automatic locking hubs and I rarely use them. It was in 2H as usual, and I left the house today and got about a block away and heard a sound that is best described as what you hear when you are grinding the gears on a manual tranny and then a sound like a transmission being dropped into gear. It sounded like the left side and was pretty loud so I pulled over. I wasn't sure what to do, so I came back home. Tried taking it around the block a few times and it did it 3 more times, so I just figured I better park it. I should add, when you here the "clunk" that's when it stops.

Anyone know what I should check for? It's not my daily driver, so It's O.K. being out of commision for a bit, but I obviously can't drive it like this. I also am assuming the hub is the problem here just due to the sounds and where it sounded like it was coming from. I have a feeling this repair is beyond me and there will be a big check to some shop in my future. GRRR!!

Any advice is really appreciated. Thanks

[72 CustomCamper]

Here is a pic of the hub. Usually what happens is the outter cage, part number 71 will melt. For some reason they made it out of plastic. I guess you can still buy that part through GM, but now would be a good time to swap them out for a set of lockouts...




Chuck

[92470]

If the piece you indicated had melted, would it cause the noise I'm hearing? Also, what is the hub doing internaly that is causing this noise? The griding, then clunk. I'm just wondering if I could drive it for a bit before repairing it. If it only would do it once, then be fine until I drove it again, it would help things. I just don't want to cause damage to other components. I know that manual hubs are more dependable, but I really prefer to keep the stock locking ones since I rarely use four wheel drive.

One more question. If I pulled it off, could I see anything, or would a guy really have to tear it apart to see the piece you mentioned.

Thanks!

[jerry moss]

junk them and put on a set of quality manual locking hubs so you'll know for sure when they are locked or unlocked. those automatic hubs are a pain in the a$$.

[OrrieG]

Since you are going to spend money fixing what appears to have at least twice as many things to go bad and melt (plastic hubs????) spend the money and swap them out for good metal manual hubs. You said you rarely use 4WD so getting out to turn them in and out will not get old. And you will know they are disengaged. What if you repair them and have a melt down back in the boonies?

[92470]

Probably sounds stupid, but I'm a freak about keeping things original. My trucks an 87' and it looks like it's brand new. I like the look of the auto hubs on front with the chrome cover and decal and going to the manual leaves me with, manual locking hubs! Honestly, I don't even drive it in winter, let alone mud, so I'm not worried about them wearing out again. Sounds like form what I read though, you can't buy the auto ones any longer, and I haven't heard about a rebuild kit. I still don't know if this is even my problem. When I put it in 4H today, the 4WD worked fine. It just makes this griding and clunk once and then it seems to go away, but I didn't drive it far. I still would like to know if this sound is familiar to anyone as the hub?

If I did have to break down and install manual hubs, anyone recommend brand, and place to buy?

[JET4x4]

I would say it's the hub. My 85 did the same thing, put it in 4 wheel and it would grind and then the hubs would lock in. Then if I beat on the truck a little it would make a ratcheting type sounds cuz the hubs wouldn't stay locked in with a good load on them.

[92470]

Mine started doing it today in 2WD. Got out on the road, then grinding noise for about 7 seconds, then clunk sound then it was gone. Went home, then took it back out and same thing. Everytime I was in 2WD. I only put it in 4WD to see if it would work due to what had just happened. It engaged very easy and worked fine. I really hate to take it to a shop.

[special-K]

They are voluntarily engaging.I`m sure they are damaged now and next will be your bearings,spindle,or axle.Since you are not the one deciding when they engage I suggest not driving it,even in 2H,until you can fix it.I swapped the autos on my`91 Suburban for manuals (Warm Premiums) when I went to 35" tires.They were functioning properly,I was concerned the larger tires would be too much for the hubs.I had issues with Warn Loc-O-Matics years ago with large tires.Although you could either lock them in or go automatic,Warn suggested for heavy loads or compression braking to manually lock them.I guess the large tires create the same stresses.They were fine for a quick engage when rear wheels wouldn`t do it,like backing up a hill on gravel.Anytime I was going off road I`d lock them in.

I would sell you my take-off factory hubs if you`d like to stay automatic.The thing with all hubs is they need periodic maintenance and few ever see that.That`s where most problems come from.

[LONGHAIR]

The simple fact that you don't drive it much is the only reason that they have lasted this long. Those things were always prone to issues.....locking when they shouldn't, jumping out of lock, refusing to lock, or refusing to unlock.....take your pick.
Even at their best, they were only "adequate" for light duty use. They would not stand-up to real off-road use and snow plows are a definate NO.
That little extra to get a boat up the ramp....they are fine.

The best thing is to spend some money to actually fix the problem, not just cover the symptoms. "Repairing" them will just cost you again later. A good set of manual lock-outs cures it.

[72 CustomCamper]

If you're worried about originality, I had an 86 k10 that came factory with manual lock out hubs. I think the auto hubs were an option...


Chuck