What is the pros and cons of posi diffs and open diffs

 

Open:

Works for most, less complicated and expensive than limited slip or locking axles. Smooth, quiet, true differential action at all times which makes corners easy.

But: Will deliver power to only one wheel under slippery or high power situations, limiting your traction in those circumstances.

Limited slip:

First, "Posi" as in Positraction, is a GM term for their limited slip design. Limited slip designs vary. For the most part, we are talking clutches, but some use cones or ramps.

Pro: Most offer true differential action, but it may be compromised depending on condition and the presence of special lubes. They distribute power evenly to both wheels, at least when new. With both wheels powered, you have more traction.

Cons: They do wear out, especially the clutch type. And both wheels spinning on an icy crowned road will put you in the ditch. Injudicious throttle inputs in corners will get you sideways also.

Lockers:

Same as limited slip, but less compromise on the locking and power distribution, and more noise, clunking, chirping in corners with some.

Locked: Great for straight lines and racing on dirt. Can make you push in corners. Not good for normal street running. Stresses the tires and axles.

For the 4x4 or 4x2 pickup being used in snow country, off road, rural poor road or other slippery or compromised surfaces, a locker in back with a limited slip up front for the 4x4 is, imo, a great set up. At least a locker in the rear. A limited slip up front may cause steering issues at times, but again, jmo, it would be worth it for the extra traction. Your driving skills would limit your problems in most cases.

JMO, others will chime in.

You can find more:

How Differentials Work - HowStuffWorks

 

Good summary. I have always preferred LS in the rear... just have to go easy on "T" intersections and sharp turns when wet or snowy... and remember to use the additive in the rear lube.