Can the collective please help I.D the diff I keep tripping over in my garage?

Its a 7.5" with push in shafts and the tag reads;

91 AA 3.91
4A 2A22

I have searched past posts, but can't find a definitive answer............AA would indicate LSD but I didn't think these came with push in shafts?

Any help much appreciated

Chris

Have a look at this link here

This has most of the codes and does suggest its the 7.5 casing.

Also have a look at the fiche' pages. Fords numbers list here

Hope that helps

[Edited on 23/7/12 by tims31]

Check out this video on YouTube:

http://www.youtube.com/watch?v=i_Enyf67KTs&feature=youtube_gdata_player


Double the wheel rotation for open diff

it can't be a LSD with push-in shafts (at least not a ford one anyway)

3.91 should the the ratio, which would be right for a 7.5" diff (probably from a car with a 2.0 DOHC or similar ? )
the nearest 7" ratio is 3.92

if in doubt take the back cover off (no big deal, its only sealed with instant gasket stuff anyway) the ratio should be writen on the crown gear and if not you can count the teeth

[Edited on 24/7/2012 by mcerd1]