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Locker question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Muddytazz, Jul 9, 2002.

  1. Muddytazz

    Muddytazz 1 ton status

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    Sorry for what seems like a stupid question, but what is the purpose of a locker and what the the pros/cons of using them.
     
  2. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> It's not a stupid question, everyone's learning curve starts somewhere. OK, from the beginning. Normally a differential is open, that means that there is nothing to aid in splitting traction between the two wheels. The reason that a car needs a differential is so during cornering the inside wheel can turn slower than the outside wheel. With an open diff this feels very natural and safe since nothing is trying to stop the wheels from turning at different speeds. The bad part of this is that if one tire loses traction, that tire gets all the power.

    To explain how a locker changes this, let's take an extreme case - one tire is hanging in the air and the other is wedged between two rocks. The tire in the air is just going to spin and spin, the tire that has traction will get no power. An automatic locker mechanically detects that the wheels are spinning at different speeds and locks the two sides of the axles together at the diff. The result is that the available power gets split between the two tires, and you keep on moving down the trail. this can be translated to all sorts of situations, such as one wheel on ice and one on pavement, or one in slippery mud and the other on solid ground. The down side of a locker is that it can lock up on the street too, such as if you hit the gas going around a corner. It can surprise you on slippery surfaces when the locker kicks in and all of a sudded the rear end will swing out.

    Between the two extremes of a locker and an open diff is a limited slip, which doesn't lock the two axleshafts together, but helps to equalize traction through the use of clutches. Limited Slips work well in mud and lighter terrain, but the clamping force of the clutches can easily be overcome in situations like the example I used for the Locker. Limited slips are excellent to use in trucks that are used mainly on the street but still see light use off road, or for anyone that does not want to deal with the normal bangs and clunks that some of the more popular lockers on the market are known to make when using them on the street.

    On the more extreme side of the locker is a spool, which locks the two axleshafts together at all times. These can be a handful, especially on the street, and are not recommended for use on the street unless you are familiar with the charactaristics that they will impart to the handling of your truck.

    There's a lot of other stuff that factors in, but this is a basic (yet I think thourough) explanation of traction aiding devices.

    Sorry for the novel... /forums/images/icons/grin.gif </font color>
     
  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    A locker is also known as a traction aid. Most stock diff's are 'open' which means if you spin the tires only one spins...
    A locker makes sure that both tires get equal power, but still allows the tires to differentiate in turns.

    The problem with open diff's in a 4x4 is if you get the truck flexed out and one tire leaves the ground all the power to that diff will be sent to the tire with the least traction. This usually stops all forward progress...
    With a locker in the same situation the tire in the air and the tire on the ground both get equal power and the truck will continue...

    Drawbacks include more rapid tire wear in the rear, and depending on the type of locker it may handle differently, clunk and bang as it unlocks etc etc. There are many types of lockers and posi's and each has it's own characteristics. The stronger more agressive lockers also have the worst street manners.

    Rene
     
  4. Muddytazz

    Muddytazz 1 ton status

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    The reason i was asking is pretty soon I'm going to be changing the gears in the D44f/12r from the stock 3.07's to 4.10's. This is my daily driver and it has a NP203 and this vehicle has seen its share of mud holes and the casual rough trails, but I doubt if I'm gonna be doing any serious rock crawling. Would there be any need for the lockers (I realize your just giving an opinion, but opinions count). Also I've heard somewhere that there are automatic lockers and manual lockers. Would the manuals be more suited for me, if any, since my burb is just an every once in a while trail runner (right now anyways) LOL
     
  5. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> What size tires are you running, and are you willing to sacrifice some driving comfort on the street for off road ability? Does anyone else drive your truck that you would not be comfortable having drive it with a device that could concievably make it more difficult to handle? Does it snow where you live? A locker can be scary in the snow if you aren't used to it and conscious that it is there. It will make the truck handle quite differently.</font color>
     
  6. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    I'd consider an Auburn posi with the carbon fibre clutch packs in the rear and call it good. From what I've heard they have decent street manners but are agressive enough off road. The only drawback I can see is if you decide to go bigger and more hardcore in the future.

    Rene
     
  7. Smurfmobile85

    Smurfmobile85 1/2 ton status

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    The Smurfmobile is our family car and wheelin' rig. I drive it everyday. We don't do a lot of hardcore rock crawling or anything. We just put a Detroit in the rear a couple months ago and it did take a little getting used to, but I wouldn't take it out for the world. We had a 14B semi-floater originally that had the factory locker (which wasn't taken care of and worked a very small fraction of the time) and noticed a little extra help even from the factory. So we decided to lock her up and see what happened. Just adding the locker has made the trail a lot more fun. We can really out wheel by brother in his Broko now. Where we used to slip just because of our size, we walk right up. Shaggy does ask some good questions though and you should consider all of them before making your decision. That's all of my success story. Happy Wheelin'!
    Deana
     
  8. HarryH3

    HarryH3 1 ton status Author

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  9. trailblazer87

    trailblazer87 1/2 ton status

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    I had blown out one of my locking hubs and all I had was essentially 2-lo, I was still able to climb a 4 foot rock ledge /forums/images/icons/grin.gif and keep up with my buddy's D /forums/images/icons/ooo.gif dge.
    An automatic locker is one that senses when you have the tires turning at different speeds and will lock the axle shafts together to make it one shaft. A manual locker, more often known as a selectable locker is one that locks the axle shafts together when you flip a switch or pull a cable, whenever you actuate it. The selectable type are rather expensive, but they are nice to have when you are trying to turn a very tight corner on a trail, or in the ice. A automatic locker works off of the torque supplied to the differential it is mounted in, the more torque you apply the tighter it will lock. If you are on the street just take it easy on the throttle around corners and it shouldn't lock up, hammer the throttle and it will lock both tires together and you WILL bark them /forums/images/icons/grin.gif
     
  10. FLASHLIGHT76

    FLASHLIGHT76 1/2 ton status

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    I personally would opt for a posi or the new e-locker. it uses electro magnets to lock a pin when engaged. It has a small wire sticking out of the diff which can be routed easily for protection and they were designed and built in the chevy 10, 12, and 14 bolt first. I'm going to buy them. /forums/images/icons/grin.gif
     
  11. Muddytazz

    Muddytazz 1 ton status

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    Is there a web site talking about these?
     

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