Which rear end?

[91Grandmarky]

Is there any way to tell what rear end i have? Without taking it apart?

Its a 91 MGM. What were the options for rears back then?

[chitownvic]

you have an 8.8.. Now to find what gear you have you gotta look at your Differential tag

[sly]

if the car is stock... you can check the AX code on the driver door VIN tag.

take that code to this thread: http://www.grandmarq.net/vb/showthre...ase-Read-First!

Post 2 will have your answer.

[chitownvic]

Oh yea forgot about that

[88Vic]

So the differential tag is on the actual differential, or it that the same as the door jam tag? I found a K code axle in a junkyard but looking at the rest of the car is making me skeptical, doesn't appear to be a tow package car and it's not an ex cop car either, and I want to be 100% before I pull it, pay for it and install.

[sly]

the AX code is on the door tag. The diff tag is on the diff (stamped metal tag). The tag on my Mark says 3.08, but it has 4L## in it (4.something ratio locker)

[88Vic]

So it can say something on the tag but be something else?

[sly]

if it's been opened... yes. Like whoever did all the drivetrain swaps on my Mark actually left the stock tag on the diff cover after swapping out the gears.

[BerniniCaCO3]

same here. I've got 3.55s inside now; it's my car, so I know that-- didn't see need to find a decal to match for the door sticker!

You can always take a 13mm socket and ratchet, take off the cover, and turn the gears. The ring gear will give the ratio on the edge, plain to see in some light.