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      11-10-2011, 12:29 PM   #26
Malek@MRF
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Drives: E92 M3, E46 M3, G82 M4
Join Date: Jan 2008
Location: Irvine, California

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Lets get a couple of the facts straight here in regards to this matter.

The 2 nuts that people undo to remove the rear section brackets DO NOT support or keep the Differential tight and in its place. There are 2 very long BOLTS that go in from the other direction (front of the car going toward the back) into 2 threaded holes on the differential mounting ears.

The 2 18mm Nuts are solely there to hold up the exhaust hanger and do not require much torque to be on them. They are not there to support the differential.

It is proper procedure to undo these two nuts and remove the exhaust system. Using a pry-bar with the exhaust weight on those hangers will damage the hangers.

The exhaust system splits before it reaches the differential (from front to back perspective)

The differential failures people have been having are not a result of these bolts being loose. They are a result of the bolt simply not being strong enough and it shears itself off In some cases, they have found the bolt to "become loose" when the bolt has actually physically stretched out. The differential bolts are threaded all the way through when they should only be threaded where they bolt into the differential mounting ears. There is compliance in axle carrier and it is partly the bushings (which lead to insane amounts of axle hop and torque shock rebound from the highly responsive motor) and lastly the differential mounts on the axle carrier itself. It is not very stout compared to the rest of the subframe, and a couple weld in reinforcement brackets would certainly alleviate much of the problem.

-Malek
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