My 95 manual trans Legacy has a bad vibration that occurs when releasing the clutch. It feels like the drive training is 'bucking'. If clutch is released carefully it is smooth with no vibration, but if a bit more torque is applied I get the bucking. I think it might not actually be the clutch since when released carefully it is totally smooth with no vibration.
It's been tough to pin down since it only does it excessively when actually driving, more when starting from a stop, but also when shifting gears if motor speed is not matched to next gear.
I've tried blocking the car or holding the brake while letting the clutch out to slip a bit under torque and I don't get much doing that.
I'm imagining this might be a motor mount but haven't seen good access points to check that.
It seems particularly bad when starting in reverse, especially if backing up a hill a bit.
Any ideas on how to troubleshoot this or check the mounts without having to tear it all down?