2007 XC90 Tranny(?) Shudders

[oxybullet]

Went through this in my '04 XC90 2.5T. It's not your transmission or the mounts - it turned out to be a bad spark plug in my case.
I had *all* the mounts replaced to no avail. Eventually a bad spark plug was found during regular maintenance that fixed the shudder issue completely.
I had no code or apparent misfire, etc. but a very annoying random shudder in moderate acceleration.

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I can confirm that a faulty spark plug causes this horrible shuddering at high end RPM of 3rd gear too. If left long enough it becomes apparent in the other gears as well. Mine was getting to the point I couldn't go above 2000 RPM in 2nd, 3rd or 4th which is when I began to suspect something other than transmission. I did still however perform a transmission flush using 3 gals of Valvoline's Max Life ATF DEX/Mercon LV and my XC90 with over 350,000 mls is running like new again. (changed spark plugs too) Fluid that came out of the transmission was black and tar like.
There was one other thing that may have caused the shuddering.... I never use the emergency brake, I just don't, because it's named 'Emergency Brake' so putting it on when parked AND putting the car in Park is for the people who like to believe their car will roll away somehow. So when I went to jack up my car, that's when I use it... and hmmm, damn thing was on. The only way that could have happened was 3 weeks ago when I had my car valet parked. So I had been driving with it on for some time. And I checked, these cars don't have a warning light when your emergency brake is on.