posi vs auto locker?

[bob95toy]

Thhis is probably a stupid quetion, well actually 2 stupid questions. What is the difference in a posi setup vs an auto locker, don't they both make both wheels spin when there is slipage? and people talk about putting a locker in the rear for a beginnig upgrade, but wouldn't the front make more sense? With hubs unlocked they wouldn't affect driving alot and in 4x4 you would have monstrous amount of traction with it being the front.

[carlos4x4sand]

I think that a posi and auto are same just a lil differences maybe manufactur. On the locker in the rear, you have a point, by unlocking the diff. driving isnt hurt. I guess people put them in the back cause while driving off road, they get alot of traction with having it in the rear, but their steering isnt hurt. Thats the way i see it

[DeadlyPeace]

Posi is alway solid whereas auto lockers are free until power is applied them. So when going around corners your wheel can turn at different speeds which they need to do. Posi does not alow this to happen and can be hard on the internal axle parts (gears, bearings,etc).

[fourwd1]

Posi, short for Posi-traction, is a trade name (Gen Mtrs I think) for a limited slip diff. You really can't compare a LSD to any type of locker.

A locker locks the diff providing full power to each wheel under all circumstances.

An LSD sends some power to the wheel with traction, where an open diff would send all the power to the whell with no traction. Since an LSD sends only some power to the wheel with traction, people apply some braking action to fool it into thinking the tractionless wheel has some traction, and the LSD sends more power to the wheel with traction.

blue text is practically unreadable against the black background, so it gets ignored

[4xfred]

;D Very well put 4wd1! My suggestion is to go here:

www.ring-pinion.com/

Check out the "tech library" section. I think it has what you're looking for. If not, post back. Later...

[mongo338]

there areso many lockers out there if you want a cheap way go for the lock right or the high end go with the detroit but dont go with a spool unless all you drive is offroad

[L8sho2003]

posi's/ limited slips are great on the street if you have a problem with spinning from a stop when it's wet or on hills or racing, etc. They generally are pretty useless offroad though. The only limited slip that ive ever used that was any better than an open diff offroad would be the auburn gear pro series. For some reason, they are about 700 bucks for a toyota so it really doesn't make much sense to buy one when you can score any of the cheap lockers for half the price or even an air locker for the same money.

[Sean]

The automatic locker works usually on a racheting system. Under heavy torque the locker will automatically engage so that both tires spin at the same rate, no matter the traction difference. The rachecting system allows the vehicle to turn corners without both tires turning at the same pace. There are two basic types of automatic lockers. The cheaper versions fit inside the existing differential carrier (aussie, lockrite) while the more expensive replace the entire carrier (detroit). These are very different from a posi traction unit which use clutches and are prone to slippage. Once engaged the auto locker spins both tires the same rate until the torque input(gas) is backed off.

Like I said i this old description of an auto locker, a posi unit uses clutch packs, which wear out and are prone to slippage. Better then nothing, but not by far.

As far as putting a locker in front instead of the back goes, what you say does make some sense. The main reasons usually out one in the back first are strength and steering. The rear axle has a distinct strength advantage over the front because it does not steer, and therefore uses no joints in transfering power to the wheels as does the front. While soild front axles are somewhat weaker then a rear, IFS axles are substantially weaker yet. As for steering, under heavy torque applications an autolocker will force both tires to turn at the same speed. If the locker is in the back this will mean a little tirehopping around a corner under throttle, or possibly a spin out, but once used to this it is easily controlled. If the locker is in the front however when going around a corner under throttle you will lose steering, as both tires try to turn the same rate they slip and end up going straight instead of turning.
Of course there are people that start out with the locker in the front, and lots of people have them in the front and back. With the proper respect for your vehicle it should not cause problem beyond breakage.

[86taco]

I have a aussie locker and it nice. on slick roads it can be a little scary. I went up a on ramp sideways once. But in 4wheel its great. Definetily worth it.

[bob95toy]

Thanks for the excellent explanations of the difference, and pros and cons of front locker. If i understand right ulocked hubs no difference, with hubs locked in steering could become tricky correct. thanks

[fourwd1]

bob95toy said:

Thanks for the excellent explanations of the difference, and pros and cons of front locker. If i understand right ulocked hubs no difference, with hubs locked in steering could become tricky correct. thanks

Correct, a locker in the front is relatively transparent w/hubs unlocked, but in 4WD hubs locked, you're pretty much going straight ahead no matter which way your wheels are pointed ;D

[zebrayota]

In my 81 I Have the front diff welded, it's never seen the road since i have owned it. In 4 wheel drive offroad i dont have any problems turning but if i let go of the steering wheel the tires turn to the path of least resistence.

[36onatoy]

i have a quesation too, i have head that you'll kill your cv's if you put a locker in the frount of a truck with ifs, i was just wondering if that was truew or not. when i put mine in the rear of my truck it was the best thing i ever did, its great.

[Sean]

36onatoy said:

i have a quesation too, i have head that you'll kill your cv's if you put a locker in the frount of a truck with ifs, i was just wondering if that was truew or not. when i put mine in the rear of my truck it was the best thing i ever did, its great.

I know some people that have done this and had success. But they were'nt beating the crap out of their trucks. I've broken cv's with an open front diff. It just depends on the wheeling you do. If it's lots of mud and sand you will be safer then if you do a lot of rocks.