Sound stops when no power to front axle. No logical connection.

I get thump from rear when under power due to subframe bushings.

Is the thump sound possibly synchronized with bumps in the road and you are getting some suspension bushing movement that only happens when the front axle is loaded?

It sounds similar to the rear subframe moving that only happens when I hit a bump while going up hill or accelerating.

There has got to be some equivalent bushings up front to isolate the front subframe and the diff possibly motor mount.

The theory is: when under load from front axle under power the diff/motor are being torqued back at the top. When you hit a bump it hops off the mount and gets pushed back from the wheel torque.

If you get a longer video it can be examined with software to see if the pops are evenly spaced hinting at gear or they are not and it can't be.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)