Are all S13 diffs LSD's?

[s13eater]

usually they have a yellow sticker on them that says vlsd, they earlly s13's din't have a lsd i don't think.

[jonnyjapanese]

I can't find a sticker on it at all. Can I tell if I remove the end casing?

[jonnyjapanese]

It does have an oil cooler with it so this would indicate it is a vlsd????? why would you need an oil cooler on a non lsd?

[30psi]

Try turning the shafts in opposite directions.

An LSD is almost impossible to turn in opposite directions.