will this LSD diff work in my Carrera 3?
 

I have a factory LSD, part number 930 332 053 02, in my 931. Will this LSD work in my '77 Carrera 3?

I can't find any info in PET about the Carrera 3, much less the diff it takes...

If the diff will work, I need to pull it before I let the 931 stuff go!

931 diff is same as 915 one which is same as early 930 one.
Crown wheel isn't though.

Crown wheel is the ring gear? If so, it should be interchangeable with the one on my Carrera's open differential, right?

In order to prevent having to readjust the backlash in your transaxle, I'd transfer the LSD onto your existing ring gear rather then swap the complete LSD and ring-gear assembly. This is because the ring gears and pinion shaft are matched sets. You'll notice that they should be scribed with matching numbers.

What I'm trying to say is this:

931 ring gear (the cogged thing around the LSD) isn't compatible with 915 ring gear, as far as I know. LSD itself is the same.

So just unbolt LSD and move it to you existing 915 ring gear.

right on. that's the info I was after.

NOW - rumor has it that 931 and 915 gearsets are interchangeable - if this is fact, is there any advantage to assembling the 915 with stacks from both boxes?

You'd have to check the gear ratios for that (assuming they're interchangable) and see if you like the combos.

As John pointed out, rings and pinions were run in together at the factory to ensure quiet operation and minimal wear. They're a matched pair and can't be separated.

Care to post some pics and info about your Carrera 3.0?

Just got it - it's a project (not running, some assembly required).
Moving out of my 951 to fund the build.