My 2007 M6 has 10,000miles on it and just had my diff fluid changed. I now have a noisy rubbing sound from the right rear wheel. BMW says it may be normal and may go away. Gets a little better after warm up but still hear some noise.

planetary gears are normally straight cut spur gears and will be noisy in operation. There may be wear in the shafts that they run on and there may be needle bearing wear. Normally you will not hear the noise as you are inside the car. The whine is an indication of a mechanical problem and will be there in all gears . There is a possibility that the noise is from the diff but if you listen carefully when driving if it is there under load but changes on over run(coasting) then it will be the diff of is on and off when you hold a steady speed it will be the diff. Have an accredited transmission specialist shop give you another opinion but if it is the transmission I would not race out right away to have it replaced.

IF you are in constant 4wd then you will not have a centre diff unless you have an AWD. The difference is that AWD transfer cases have a centre diff that allows different road speeds between the front and rear diffs as in going over speed bumps and dips ion the road It is the same operation in the front and rear diffs that allow one wheel to go faster than the other when cornering. However in 4wd drive there is no diff action in the transfer case and both front and rear axles drive at the same speed regardless of speed bumps and dips in the road . This action produces what is known as torque wind up which results in the handling characteristics. This torque wind up places stress on all the drive line train and results in failures such as .that you describe.. This wind up is not noticeable when driving on loose surfaces slippery surfaces or in mud as it is allowed to escape when the wheels spin . If you have an AWD with diff lock capabilities then check that the diff lock is operating correctly

wd diff lock only locks the front to rear diffs not the 2 wheels on the same diff. To have both front wheels driving as you require will need limited slip diff in front or locker in front Be hard to steer in tight areas but they are available.

possibly bearings in your wheel hub. they get quiet noisy when they need changing

first swap to a front tyre to eliminate that issue


new bearing shouldn't be rumbling
to get the bearing square on and home
did you use a press to fit the bearing to the rear axle
or tube method ?

and did the seal kit have this nifty plastic seal fitter so axle didn;t rip the seal surface

The rubbing sound you hear may or may not be related to the differential condition. If the diff lube has not been changed in the last 12,000 miles, it's due for a change: it is recommended as normal service.(front and rear) If the diff is leaking or very low, or, if there is a noise, just replacing the lube won't help. You need to correct the problem.
The average JL tech is well trained in removing and replacing oil drain plugs and filters. Leave the real diagnosis to a trained experts. You may have a piece of plastic column cover rubbing (easy to fix) or something more serious such as a hub bearing or differential internal bearing failing.

Hi, there, Check your break pads. Could be from there.
cheers

diff bearings on way out jack both rear wheels off the ground --turn them by hand good chance you will pick up which side and how bad but it wont keep going for long the longer you leave it the more parts could get damaged

Check tire size and add a Limited Slip additive in the transfer case!

Hard to say, but here is something important to check. Get the rear end up on jack stands (safely), remove the wheel and take a closer look. Check that the LAD high pressure hose that runs from the pressure accumulator (AKA bomb, because it looks like one) to the bottom of the strut, is not rubbing on anything. If it is, get some open ended spanners and slightly loosen, re-position, and re-tighten the hose so that it does not come into contact with anything when it moves (make sure you have some spare pentosin first, or drain the fluid into a clean container for reuse). Sometimes when a mechanic fits these hoses they don't care enough to make sure they're not rubbing anything. It happened to me, but I wasn't lucky enough to hear it first, and it wore through the hose. If this happens, you will lose power steering and the rear suspension will sit down, so you will need a tow truck, about $100 worth of Pentosin 7.1 (you can't use ATF or regular brake fluids), and of course a new hose. The latter two can be ordered from www.bavauto.com. Good luck.