At 70 mph the tire rotates 14.06 hz.

14.06*3=42.18. Damned close to one of the repeating vibrations but I think the CV axle has 5-6 ball races.

Since the vibration didn't seem to follow the spare I don't think it's bearing or suspension other than possibly any spring component that has a resonance approx 42-43hz and a minor wheel out of balance matching it.

The key to me is the "under power"

That screams "drive train".

Step one; get to reproduce at a lower speed say 40-45 and on a particular Hill on a particular curve up hill slight acceleration.

Once you can find a way to reproduce it (use m/s to force repeatable RPM), then use a different gear everything else the same.

You want to exclude the transmission as the source.

If you get the same shudder at the same speed rise (40 up to 45 as example), even when in different gears it's not likely in the transmission.

14.06*4.1=57.646 (that should be the speed of the drive shafts at 70 mph, which should exclude the guibo unless divide by 3 or 6:

57.65/3=19.217 57.65/6=9.608

Those would be the suspect values for guibo at 70.

You said the csb had some wiggle to it? That doesn't sound right. When I removed and replaced on the e92 I service, I don't recall any wiggle i could impart myself.

If you can move the shaft sideways by hand or even a small prybar I think you've found the culprit.

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