Is this an LSD?

[Ezz]

While in the process of cleaning the diff, i noticed the “S” paint.
The ratio is 38:11 that is 3.45:1
Car it came off of is a 1971 2800 E3, but I am not sure if this is the original diff.

The output flanges rotate the opposite direction so if an LSD, could it mean it is worn out?

 

[Ezz]

“S40” stamped.

 

[Ian C]

Do the output flanges turn the same way when the pinion is turned? The s40 doesn't have a static pre load like the s25, the only real test is either to measure the inner components, as described in the blue book, our drop the clutch on gravel and count the lines. There were a couple of different versions of friction plate, one type requiring non mineral oil, none of which are easily available as far as I know. Replacing the lsd centre with a modern version is possible

 

[Ezz]

Do the output flanges turn the same way when the pinion is turned?

They do turn in the same direction.

I appreciate your reply. I learned something about the s25 vs s40 and the static preload.

 

[autokunst]

Seems like you have a very nice and desirable diff there. Good find!

 

[Ezz]

i was reading a little more about them and with the info above it is an LSD. Any idea of the value of it?
Here is another pic of the spindle.