How do you lock the hubs on a 1986 K5 Blazer?

Question by Matt: How do you lock the hubs on a 1986 K5 Blazer?
Im considering to buy a 1986 k5 blazer (Silverado trim package). The thing is im not sure how to properly lock the hubs to go into 4×4. Also im not sure if it is automatic or manual locking.
Please tell me in detail.

Best answer:

Answer by justin plainold
there are millions of auto lock hubs out there on gm products, manual lock hubs have a twist lock on the end of each hub, so if there is no twist lock on the hubs, they are automatic, some years you can put manual hubs on, most rigs after 90 up to the present day are automatic, this is a bit harder on gas because the whole hub turning, whereas with manual hubs just the wheel turns.

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  1. Pretty uncommon to see anything that vintage BUT automatic locking hubs (I’ve owned three mid 80’s K5’s) unless they were swapped out.

    Auto hubs have a “4X4” sticker on the hub which matches the 4×4 sticker on the rear hub caps.

    Manual hubs will not have the matching sticker, and will be a simple plastic or metal (depending on brand of hub) piece with a raised straight section across the middle, that you can turn with your fingers. Usually the hub housing is marked “locked” and “unlocked” which the hub will line up with when turned.

    To engage auto hubs, you put it in 4WD and drive forwards. That’s it. To disengage auto hubs, you put it back into 2WD (sometimes need to back up first in 4WD to relieve some drivetrain bind) and then back up for a minimum of 10 feet.

    Be cautioned, the auto locking hubs are universally considered garbage (they are, to their credit, approaching 25 years old at this point, give or take), and I personally, on two out of the three blazers, have had those hubs fail, even after being disassembled and properly lubed. Problem with them is that when they fail, is when you need them, which may leave you stranded. So it is very common to see aftermarket (usually Warn) hubs swapped in.

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