12-29-2012, 03:39 PM
Join Date: Dec 2012
Location: Vancouver, Wa
My Ride: 2004 M3
That is because the car is putting out very little torque in 6th at HWY speed. Our cars have suffered from weak diff mounting bolts and BMW, superseded to different bolts to correct the problem. There are three diff bushings, which these bolts run through. Two of them are toward the top on the rear cover, and are the bolts that tent to shear. There is one going horizontally in the front center. The bushing are a good robust design, so unless your up around 100k miles it would not be my first suspicion. Also while under there its good to look for subframe mount cracks. The most common and visible will be at the rear drivers side mount. You need to clean the area real well, grime and undercoating will conceal smaller cracks.
Originally Posted by bbenj10
One thing I have noticed is that it doesn't make a noise when travelling at highway speeds in 6th gear. It only seems to be around town in 1st through 4th gears. And the sound occurs when I'm already in gear, coasting, and then re-applying the gas.
Edit- You will want to remove one at a time, so your diif stays in place. You need to look at this before driving any more, its a possible safety hazzard!!!
2006 E46 M3 ZCP silver gray on black SMG
|Stoptech BBK ST40 X 355mm| Style 219 wheels|
|Ceramic coated euro headers| Custom 200 cell section 1|
|TTFS Motor & SMG tune, 315 whp| GC coil overs |
|Carbon Fiber Intake|AA GEN3|AC Strut Brace|Eibach/Koni's|CSL/SMG Flash|
|Victory UDP's|HPF Sub Frame Plates| PF Subframe Bushings|Rtab Limiters|PFC DD Front Rotors|
Last edited by NICKBRUM; 12-29-2012 at 03:41 PM.