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Locker vrs. Limited Slip

1978Blazerk5

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Its probaly been discussed before but

what the difference between a locker and a limited slip?

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Thanks
 
A locker keep both tires spinning at the same speed at all times as long as your on the gas. Some stay locked period!

Disadvantage: Scary on wet streets(rain but can be avoided with smart/safe driving), tires wear faster, sometimes noisy.

Advantage: Awesome for rock crawling, Mud, Sand, and Trails:D
 
Limited slip locks while traveling straight. Will power tire outside of turns to help with steering around corners. Made for street use.

Disadvantage: Not a locker:D, Sometimes fails to engage at worst times, Will wear out after time, Not a locker:D
 
I am asking cause Ive been thinking about something for the front of my 78' to make it a little better in "off road" conditions
 
Limited slip: Will basically try to supply some power to both wheels, but should be left for street driven cars, I dont think it has any place on an off-road vehicle.

Locker: If you get a good one (Detroit recommended) they can be virtually unnoticable, and will always turn your axles at least as fast as your differential is turning (But can unlock individual wheels to rotate faster in the same direction that the differential is turning, as in the outside wheel in a turn)

I have a Detroit locker in the rear of my truck, and when I tell people that are riding in the truck that I have one, they always react the same way, thinking that they are all loud, Mine is basically undetectible as long as I am not stomping on the gas around turns. Mine is my daily driver, and I am glad I went no other way! I plan to do the same in the front differential as soon as I can afford to.

Limited slip locks while traveling straight. Will power tire outside of turns to help with steering around corners. Made for street use.

Disadvantage: Not a locker:D, Sometimes fails to engage at worst times, Will wear out after time, Not a locker:D

What kind of limited slip are you talking about?:confused:
 
If the word SLIP is in it ( besides a Powertrax NO SLIP which locks and a Powerlock which slips ) it SLIPS . Thats the difference between a locker which LOCKS :thumb:
 
No offense to the people posting above me but so far most of the definitions are pretty poor.

Open diff:

An open differential will supply equal power to each tire as long as neither is slipping. During a corner, the spider gears in the differential allow each tire to spin the appropriate speed and thus the operation is very smooth.

If one tire loses traction, 100% of the power will be transferred to that tire. In other words, the power gets routed to the path of least resistance (the tire that is slipping) and you don't go anywhere.

Limited Slip:

Limited slips generally operate like an open differential with one exception: they generally have some kind of clutch that helps transfer power to the wheel with traction (hence "limited" slip).

If one wheel has plenty of traction and the other has very little (or none) a LS isn't going to do much (if anything). They work well in the snow/mud, pretty poorly in the rocks.

"Positraction" is interchangeable with limited slip, they're both general terms for a wide variety of differentials.

Spool:

A spool positively locks both axles together all the time. This means that each tire receives full power all the time regardless of how much traction each tire has.

The downside is that its hard on tires (since there is no "differential" anymore, the inside tire has to break traction during turns) and can be tough to deal with on wet/snowy roads.

Locker:

Lockers operate under the same principles as a spool but have some element to allow them to unlock.

Mechanical lockers (Detroit, lock-rite, etc.) have a spring that keeps them locked. Mechanical lockers should generally unlock during corners (and stay locked in 4WD) but have harsher street manners than an open diff.

Selectable lockers basically offer the best of both worlds. They can be open or locked at your choosing. The downside to them is the cost (~twice the cost of a mechanical locker) and reliability (most are very reliable but selectable lockers are more complex).
 
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Mechanical lockers (Detroit, lock-rite, etc.) have a spring that keeps them locked. Mechanical lockers should generally unlock during corners (and stay locked in 4WD) but have harsher street manners than an open diff.

Why would being in 4WD have any effect on whether it locks or not? I also think the term "Locked" is not really correct (Like with a detroit for example) because it doesnt technically lock, it just makes it so the axles have to go at least as fast as the carrier, and in the same direction that the carrier is being powered. Either axle can always roll faster than the carrier, so it isn't technically "Locked".
 
Why would being in 4WD have any effect on whether it locks or not?

Mechanical lockers (like Detroits) are very torque sensitive. Basically when torque is transferred though the axles (i.e. you are hitting the gas pedal at all) the locker will be locked. I have never had either of my Detroits unlock when in 4WD.

I also think the term "Locked" is not really correct (Like with a detroit for example) because it doesnt technically lock, it just makes it so the axles have to go at least as fast as the carrier, and in the same direction that the carrier is being powered. Either axle can always roll faster than the carrier, so it isn't technically "Locked".

To me, "locked" means mechanically connecting both axle shafts together. All lockers do this (including detroits). I don't understand what makes you think mechanical lockers aren't "lockers" (your above statement is pretty tough to understand) but I can practically guarantee that you are missing something. Mechanical lockers do solidly lock both shafts together as much as anything.
 
I think some of you need to pull apart your lockers next time you have them out and see how they really work. And how could you possibly know if your Detroit never let an outside wheel spin faster than the carrier while in 4WD? It's not like the Detroits turn into spools, just because you shifted into 4WD. I fully understand that the tires will always be spinning in the direction of the differential, but the fact that they can be allowed to spin faster than the differential in the direction of rotation makes the term "Locker" kind of misleading, since it technically acts more like a ratchet.
 
I think some of you need to pull apart your lockers next time you have them out and see how they really work. And how could you possibly know if your Detroit never let an outside wheel spin faster than the carrier while in 4WD? It's not like the Detroits turn into spools, just because you shifted into 4WD.

I know exactly how they work and have had several apart.

When you shift into 4 low, IME the detroits will stay locked whether you are on the throttle or not.

Again, "locker" means that it can mechanically connect both axle shafts together which a Detroit does.

I fully understand that the tires will always be spinning in the direction of the differential, but the fact that they can be allowed to spin faster than the differential in the direction of rotation makes the term "Locker" kind of misleading, since it technically acts more like a ratchet.

I think you are confusing a locker with a spool. Just because a Detroit unlocks ("ratchets") sometimes certainly doesn't mean its not a locker.
 
There are also a few different limited slip designs out there, flat clutch style (which is most of what GM used, Auburns are the exception essentially) is "engaged" at all times.

The axles are held together via the springs in the assembly exerting pressure on the clutch plates. The reason they slip is that as soon as the force acting on the tire exceeds the capacity of the springs, the clutches slip. This is why you can get different rated springs for these setups.

Why these aren't good for a truck is pretty obvious. Think about a car with a limited slip. Going around a sharp corner on dry pavement (at normal speeds) you don't notice it's there, as the clutches slip pretty easily due to the high traction of the wheels. Take that same corner in rain or snow, and you can spin the car around because there isn't enough traction to force the clutches to slip, reducing traction further if the throttle isn't reduced.

In an off-road situation, you take it one step further, because the load on the individual tire can be MUCH greater than on a car on pavement, due to overall vehicle weight and terrain. One wheel off the ground, up hill, your limited slip isn't going to do anything BUT slip.
 
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I think you are confusing a locker with a spool. Just because a Detroit unlocks ("ratchets") sometimes certainly doesn't mean its not a locker.

You are completely missing what I am saying. I agree that it is known as a locker because that is the terminology for this type of diff, I was just saying that the term is misleading. An ARB, or some other type of electrical locker "Locks" the shafts together, but I would not consider a diff that allows one tire to roll faster than the carrier a "Locker" if I was the one that had to come up with the term for it. I just think is a misleading term, and most people dont know how the detroit for example, actually works.
 
Technically a detroit locker is called a NO SLIP/SPIN, so there, its not a locker
 
You need a really hard surface , and enough wheel speed to make the teeth overrun on a Detroit or Lockright type with dog teeth . Which is exactly what street driving will do .

I have never , ever , ever , had a locker unlock wheeling .

For those that don't know how it works , when the carrier spins , the center pin comes around with it and pushes the drivers out against against the side gears locking it . Now those drivers are not perfectly tight in there during this , they have just enough room to move out to ratchet for turning , which is why there are springs in there .

Now to force the driver out just enough to make the ratcheting happen , there needs to be sufficient speed over a hard surface , such as a sweeping turn on a freeway ramp , or no torque on the driveshaft , such as turning around in a parking lot barely touching the gas pedal .

They don't just unlock wheeling , they work with a tire in the air .
 
just put a detroit in my D60 under my cummins ram about a month ago when i totally rebuilt the axel and it is the best thing ive ever done, if its in 4wd and your not on the throttle it ratchets when you get on the throttle at all (cummins torqe has alot to do w/ it i'd suspect) it locks up you can tell in the steering it wants to go straight or where you can hold the wheel, gotta fix the power steering and it will be awsome, the D70 in the rear is gettin a detroit in a month or 2
 
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