ID my Diff?

[Jed Rogers]

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?

[Jed Rogers]

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...?

[Joe Bob]

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

[Jed Rogers]

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.

[Joe Bob]

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

[MBAtarga]

Pelican user Matt Monson could probably tell from your picture.

[Matt Monson]

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.

[Jed Rogers]

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.

[djpateman]

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.