ID my Diff?
 

I'm probably the 3rd or 4th owner of my '87 911 Coupe and it has a limited slip differential, but I have no idea what brand it is. Here's a picture of it when we rebuilt the gearbox a while back.

Any guesses?

http://forums.pelicanparts.com/uploa...1490924634.jpg

I did some google image searching and found another thread and it looks like this is a stock Porsche LSD...? From what I've read, Porsche did not offer LSD in 1987, so I'm guessing a previous owner put this in at some point...?

My 83 has an oem LSD. What is the trans' part number on the spine on the bottom?

Joe Bob, I'm not sure as this sucker is back in my gearbox already and I didn't take any other photos :(

However, this is for a g50 box, so probably not the same as the one you have for your 915... i would assume.

Well, the number will tell if stock, but the previous owner coulda added it.

Pelican user Matt Monson could probably tell from your picture.

Very simple... A factory ZF G50 LSD will have a part number starting with 406 stamped in the side. If it was original to the car, the gearbox will have a 2 stamped between the G50/00 type number and the start of the serial number. If it has a 1 instead it was an open diff.

Thanks, Matt! I'm changing my gear oil this weekend, so I may peek in there and see if I can locate a part number without tearing too much apart. I'll check the gearbox S/N, too. That's super helpful in figuring out this little mystery. I really appreciate everyone's help here.

If the trans has a 2 stamped between the G50/00 type number and the start of the serial number, please try and get a photo of it; it makes great documentation.