Hi all,
Is the rear subframe the big axle that holds the differential or is it part of the main body/chassis where the differential is bolted to?
Thank you

The subframe holds the rear suspension to the car body via 4 rubber mounts. The rubber mounts isolate the noise and vibration from the cabin of the car.

Search "subframe" in the various forums and you will get more info.

If you have a e36 BMW pre 95 check the subframe mounts at the body because they have a tendency to crack and pull out of the body over time.

See pic:
http://files.automotiveforums.com/gallery/showgallery.php?ppuser=205495

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