I would stop driving it, like right now and have it looked at. Syncro
transmissions only get more expensive to fix the longer you drive them.
    Noise goes away when you press the clutch because you remove the load,
Sounds to me like it is rebuild time. I just got through doing this twice
within 10K miles because of a bad Pinion Bearing and a loose carrier
bearing.
     Sorry to sound the horn ,but this is just to close to home.

                                    Stacy

On Mon, May 25, 2015 at 11:20 AM, Mark McCulley <markmcculley@gmail.com>
wrote:

> My '87 Syncro is experiencing a noise emanating from the transmission area.
> It does not sound like it's internal to the transmission, it's not a gear
> whine sound. I would describe the sound as rotational vibration sound. I do
> not feel the vibration, just hear it. The sound occurs only when I let off
> the gas and coast, as when approaching a turn or going down a slight hill.
> The sound will go away if I accelerate. It will also go away if I push in
> the clutch pedal.
>
> The transmission does have a driveshaft decoupler. The sound is unaffected
> by whether the driveshaft is coupled or decoupled. It also made no
> difference when I removed the driveshaft altogether.
>
> Suggestions as to what might be causing this sound?  I'm guessing it could
> be a throw out bearing or something else in the bell housing.
>
> -Mark
> Seattle WA
> 1987 Syncro Westfalia
>

--
   1989 Swedish Tristar with Aluminum gates and Atiwe 16" Wheels.
    Oldest son is an Eagle scout.