It was interesting as I looked for internet information to support what I had posted. Those with limited slip rear ends posted the method you had (which is correct) and those with open rear ends posted what I had (which is also correct). What I did NOT find find was any posts stating 'there are two methods, for two different rear end types.' Thus it seems that whatever method people had used at some point in their life..., they thought applied to both.

But, yes, I learn new things all the time (or learn I was was wrong). Sometimes to my embarrassment, but ultimately for the long term betterment.


BTW, to the original 'how to tell' question above?  If you jack up one wheel and the tire rotates you have an open rear end and use the "open" method listed above. Note that the car needs to be in neutral and the brake off so properly secure the car from moving/falling on level ground.  If the tire will not rotate you have a limited slip/posi traction type rear end and need to use that method listed by Dick above.  This will require both rear wheels being off the ground and thus it only increases the need for the mentioned safety aspects.

The tag on mine at the bottom reads 1867 224A.  The high one looks like FU-5FC with perhaps something before this!
Fred