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cesar9 05-03-2005 12:53 PM

types of differentials
Hi guys:
This question has been probably asked before, but i have been hearing people talk about types of differentials, and i am confused. Limited slip, locker, posi track(or something like that), Detroit locker, and what is the one that when the car is in the air, and you turn one tire, the other goes the other way. Can somebody clear out this for me by telling me their differences, uses and other info?
I would really appreciate it. Thanks.

mj_lover 05-03-2005 01:47 PM

diff's 101:
open diffrential: most comon, found in almost all cars and trucks. allowes wheels to spin at different speeds, this is also the one where if one wheel is stuck, the other will spin lika mad in the other direction.

limited slip, posi: a happy midle ground between full locked and open. basically this unit always keeps a little power to the stuck wheel, assistin in traction, but not as nice for turning. (when you turn, one the outside wheel travels faster then the inside wheel)

lockers: brands include detriot and arb. this unit keeps full power on both wheel no matter what. used alot in off roading, and drag racing. turning is all but impossible with locked diffs.

if you need more info hit and do a search.
hope it helped!

tm454 05-03-2005 02:36 PM

off the cuff...
sound good to me Dude....are you planning a diff. change over in the future? They come in a lot of different sizes too and I'm not just talking gears here. The housing are big and small and GM and Ford and Chrysler.


Rat Rods Rule!

nosaj122081 05-03-2005 04:00 PM

Wrong on the locker...

It is either fully locked or fully UNlocked. It essentially acts like a spool or an open rear, depending on if you're under throttle or not (the throttle is like the on/off switch for a locker).

Turning is no big deal with a locker... Didn't even notice I had a locker most of the time, occasionally with a slow (like parking), sharp, under throttle turn you'd hear a bang but for the most part it is no big deal.

IMO, and this applies only to 9" Fords, I'd never consider any other differential than the Detroit Locker. Opens just flat suck, I have a pile of them in the basement, just put one in my Mustang to get it ready to sell (no WAY someone's gettin' my 3.89 locker unless they pry it from my lifeless arms), and I've fried too many clutch LSD's to have a good opinion of them, they're just Mickey Mouse in comparison.

mj_lover 05-03-2005 07:40 PM


Originally Posted by nosaj122081
Wrong on the locker...

It is either fully locked or fully UNlocked. It essentially acts like a spool or an open rear, depending on if you're under throttle or not (the throttle is like the on/off switch for a locker).

thanks for the correction! :welcome:

comet boy 05-05-2005 10:06 PM

a lock uses a manuel locking device such as locking gears or air activated gears that mesh together to turn both axles
posi's use abestos or carbon fiber clutches that put pressure on the spider gears when going forward but the pressure is relieved when turning.
Spools are a replacement for spider gears and both axles turn no matter what not for street use!

BillyShope 05-05-2005 10:55 PM

Also wrong on the open differential, MJ. (This isn't your day.) :) When one is stuck, the other spins in the proper direction. But, with the car on a lift and the transmission in gear, if you turn one forward, the other goes backward.

I had a buddy weld up the spider gears on a '56 Chevy many years ago. While driving it on the street, I could hear the tires chirp as I turned a corner at slow speed and while I parallel parked, but, other than that, I couldn't notice the difference. The right rear no longer went up in smoke at the strip, though.

mj_lover 05-05-2005 11:04 PM

you know, that bad part is, i do know that.....grrr, i feel stupid now... :pain:

cesar9 05-06-2005 02:34 PM

thank you guys for all the info, now i got it all figure out.


willowbilly3 05-08-2005 05:00 AM

Remember that limited slip is just what it says, limited but not eliminated. I suppose specs are different for different sized units but basically they slip at about 250-275 ft./lbs. of torque when they are new and degenerate with wear. You should do a search on the different types to get a better understanding. In addition to the cheapo limited slips there is the Torsen-Gleason type, the Auburn, the Detroit locker and several others. The T/G is probably one of the toughest and a favorite of off road 4x4 enthusiests. If you plan to run welded/blocked spiders or any kind of spool, then you should put a straight line on your axles and pull them regularly for inspection. I don't want my family in the oncoming lane when you snap an axle.

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