[Bill128]

I have an 2006 330 xi. AWD

do all wheel drive cars have limited slip rear diffs? I ask because I am getting a noise like a mortar and pestle...rolling and grinding...noise at low speed and sharp steering angles. I wonder if it could be an LSD problem?

Also, the manual says there are many didffferent kinds of lube. Some lubes are for LSD and some for opens. How do I figure out which one I need?

TIA

[Suvorovo]

Same car, 6 speed. I also have the same issue at low parking lot speeds on left turns only. Hopefully someone will chime in. Sometimes I hear it, sometimes I don't. I suspect it's something to do with parking brake/adjustment or other brake hardware. My rears are severely worn out and will be replacing them shortly and differential fluid was replaced at 90k by previous owner and 130k by me.

We do not have LSD. 75W90 will do just fine.

[Peter Morrin]

I would immediately check out your parking brake hardware. The brakes are anchored to the dust shield which can rot out. There are fixes. You don't want the parking brakes jamming inside the hub (ask me how I know). If you have to replace your parking brake cables, plan on buying new ones. They seize to the back of the rear caliper and are a bear to get out.

If that is not your problem, have you considered a front or rear axle problem?

[drawz]

Change front and rear diff fluid - they're non-LSD and 75W90 is the spec. Also change the transfer case fluid (Shell TF0870). While you're there, check your front drive shaft (not axle) for play - the u-joints fail. If that doesn't do it, check the axles, CV joints, and wheel bearings.