[cardoc]

LL Bean or VDC?

There's a few possibilities in the drivetrain. CV Shafts, engine or transmission mounts, upper torque arm (mounts from the upper transmission body to the firewall), rear differential or driveshaft u-joint or carrier bearing bushing.

In the remainder: exhaust parts, suspension/steering or something else in the engine compartment has a loose mount.

It all depends on where you hear it from and how often it does it. Do you feel it while driving at any certain speed? Any noise when turning? Any loose feel to the steering or handling? Can you replicate it at a dead stop in park or neutral? Do you feel it in a particular area of the car, say driver's seat, floor or is it something that rattles the dashboard?

 

[cardoc]

Sounds like it could be an axle. Its been noticed that some aftermarket shafts create noise/vibration in gear. Sometimes just for an instant during torque transfer, sometimes getting up to speed.

You will be able to tell which one was replaced by the condition. It won't be as dirty and dull looking as the old one. Non Subaru axles will have black boots on the joints.

It could also be a control arm bushing or engine/trans mount. Mounts can be checked with the brakes set, in gear and give it a little throttle and see if the drivetrain shifts. Someone will have to be under the hood looking while someone inside works the throttle in D and R. Same with the suspension. Movement can be seen if it is severe.