[Tigers] Posi rear ends.

[Smit, Theo]

If the carrier is out of the diff it's pretty easy to tell. Open diffs
have two spider gears and two side gears and that's all, and the carrier
is just an open (rounded) square that holds the gears in alignment. You
should be able to turn the gears by hand. Any locking diff usually has a
much more substantial carrier that surrounds the spider gears, and it
can have two or four spider gears, and on a Salisbury type diff you can
see ramps on the spider gear shaft retainer that actuate the
torque-sensitive clutch pack.

Open diff:
http://performanceunlimited.com/classifieds/photo50.html

One type of LSD:
http://www.drivetrainspecialists.com/categories/posi-and-limited-slip/pr
oducts/product-570.html

Theo