Postitive traction- opininons

When the cars like that were fairly new, it wasn't hard to find a posi rear end in a wrecking yard fairly cheap. But 40 years later, I doubt you will find a GOOD original factory unit, at least for decent money. If you have a good rear end now, with an appropriate gear ratio, you probably could get it set up with an aftermarket limited slip differential or a locker for around $1000.
If you need a different ring and pinion, this would be the time to do it, since the set up is more or less the same with new or used gears.

I have driven cars with both open differentials and limited slips, and a couple of trucks with lockers. In general, I would say it is easier to drive a car with an open differential than one with a tight limited slip. On the other hand, if you are fooling around with drag racing (or other straight line acceleration contests!, it just doesn't work well to only spin one tire. I think the electric locker would be a super compromise--an open differential most of the time, but a locked rear end when you throw the switch.

If you have a lot of power, you probably should worry about breaking the stock axles. And with C clip axles, when they break, they often come out of the axle housing. BE CAREFUL and good luck!

Geared Torque-Sensitive Differential

Geared, torque-sensitive mechanical limited slip differentials utilize worm gears to "sense" torque on one shaft. The most famous versions are:

* Torsen differential invented by Vernon Gleasman in 1958, then sold to Gleason Corporation, who started marketing it in 1982; * Quaife differential, sold under the name Automatic Torque Biasing Differential (ATB), covered by European Patent No. 130806A2.

Geared LSDs are less prone to wear than the clutch type, but both output shafts have to be loaded to keep the proper torque distribution characteristics. Once an output shaft becomes free (e.g. one driven wheel lifts off the ground; or a summer tire comes over ice while another is on dry tarmac when the car goes uphill), no torque is transmitted to the second shaft and the torque-sensitive differential behaves like an open differential.

Geared LSDs are dependent on the torque and not on the speed difference between the output shafts. Such differentials may be acceptable on dry pavement, but are not adequate on slippery surface[3].

Geared LSDs may be used:

* to reduce torque steer in front-wheel drive vehicles; * as a center differential in four-wheel drive (e.g. on Audi Quattro); * in rear-wheel drive vehicles, to maximize traction and make oversteer easier to manage (as in Drifting). Although, for professional drifting, a geared LSD is less effective compared to a clutch type LSD.

Don't mind the grammar,

Aaron

A posi makes life much more interesting in the rain and snow and ice. With an open differential too much throttle spins just one tire. With a posi, you spin both rear tires, and the entire car spins around very easily. It's fun and you go "wee" when you do this at a stop sign. It's not so fun when you snap into a spin on the exit ramp or a turn on the backroads.

A posi gives better overall traction and holds it longer than an open differential. But when a posi rear loses that traction, it loses all of it, instantly. This makes a posi type rear more demanding of your driving skills.

Chuck (CA)