Automatic Transmission vibrations

[Dan C.]

Hi guys,

I have an '99 Subaru Legacy Outback with 99 K miles. Recently I noticed
when I'm standing idling (at a stop light) that the car vibrates more
then usual. When I put the transmission in neutral the vibrations goes
down to normal engine level (I'll say). The higher vibration is
noticeable in at all speed including R.

Does anyone know what is the problem, or how bad it is?

Thank you.
Dan

 

[John]

Dan,
I have read in this NG that this is from the half-shafts, not the trans. I
have the same issue in my 95 Legacy and so far the right half-shaft has been
replaced (for other reasons) but I still have the vibrations.
I dont think it causes any harm other than the annoyance of the vibration so
I'm not too eager to replace the other shaft until it definitely needs to
be.

 

[ed]

Don't think the half shaft is the problem; since this in not turning when
the car is stopped, it would not cause a vibration at idle when stopped. I
would have the idle speed checked and adjusted if necessary, and have the
motor mounts checked. If these get soft with age, the vibration level could
increase, especially at idle, when there is more vibration since the motor
is turning so slowly. Not a big problem in any event.

Ed B.