I'm sure this has been done 1000x but I thought I would share here for future reference. I just got done installing a rear diff from a 97 or 98 lego outback (on my 92 legacy), with female inputs for the axles. I was able to use the stock rear axles with the stubs removed from the original diff and pinned in place. I did not have the correct socket for the stubs but managed to get the star head bolt out with a 8mm 1/4" drive deep socket without drama or harm. The outback axles are a touch longer and I did not try installing them, I looked at swapping the inner cups but the dimensions of the 2 axles are different in regards to the bearing cage as well as thickness of the shafts (old ones where thicker).

 

Next issue was the pinion flange, the bolt pattern varies- I happened to have the donor driveline and simply used just the rear potion (diff to carrier bearing) otherwise one would have to try to swap the flanges- and I have no idea if the inner dimensions would interchange as far as pressing into the front pinion bearing.

 

I went through all this since my bearings in the unit were TOAST- bad rattle noise that appeared @45mph and increased in frequency with more speed, letting off the gas would get you a nice death rattle noise before quieting down.

 

Super stoked to get this sorted out- I had rebuilt the 4eat last year after losing reverse and had been worried this noise was something I had done wrong- driving it the sound seemed everywhere. Putting it up on stands and disconnecting the rear narrowed it down.

 

Glad to have my mountain car back!

All the subaru r160 pinion flanges will swap. I've done it a few times over the years in similar situations.

What's your method for holding the pinion flange in order to break the nut loose?

An impact is the most effective way get it off.