Extreme cold transmission noise under load

[dmcclosk531]

Hello All,

I'm experiencing some noise from my manual transmission (i think) during
the recent cold snap in northern Vermont. The car is a 09' with 100,000
miles on it.The noise only happens when I'm on the throttle and loading
the engine, stops completely as soon as I lift off the gas.

This only happens when it is <5°F, this morning it was -12°F and it
was very loud. I would describe the noise as a knocking or clacking.
There are also two levels to the sound. Under light throttle I have one
noise, and under hard throttle I have a different, louder, worse
sounding noise.

I get the noise even after letting the engine warm up completely, which
leads me to believe the noise is in the gear box, as this does not warm
up while idling. Also, the noise does go away after 10-15 minutes of
driving. It seems to happen in all gears and does not happen when I rev
the engine in neutral. From the driver seat, the noise seems to come
from directly below the center console, maybe a bit in front of the
shifter.

I have replaced the transmission fluid, maybe 15,000 miles ago with Subaru extra-s fluid.

Has any one else experienced these symptoms?
       

[nipper]

Manuals do all sorts of fun things when it is extreemly cold out, as you said, they don't warm up idling.

 

Does the noise seem to match road speed or engine speed?

[dmcclosk531]

Thanks for the response!

 

Seems to match engine speed more than road speed, so it could be something related to the input shaft of the transmission. The most noise seems to be between 1500 and 3000 rpms. It might even stop at higher rpms above 3000. Very dependent on engine load. If I accelerate slowly, it doens't seems as bad as if I work the engine.

[nipper]

What happens to the noise if you depress the clutch? Can you feel the noise in the clutch pedal?

[Fairtax4me]

Fluid is filled to the correct level?

Try to avoid heavy acceleration when the trans is cold and the fluid isn't yet working around as well as it should be.

 

The trans will warm up slightly while at idle, just not as quickly as by driving it. As long as the input shaft is spinning there will be friction between the shaft, gears, and fluid that will cause it to warm up some. The engine block also transfers some heat to the trans via the bell-housing, and there is an exhaust pipe that runs right by the trans which gets warm pretty quick, and the radiant heat from that will warm the side of the trans.

 

Clicking/knocking that is engine speed dependent is often the main input shaft bearing. Those are a common failure on older models, but they usually make it to at least 150k before having any problems. The only ones I've heard of failing sooner than that are in cars that are poorly maintained or have had contamination (such as water) of the gear oil. Haven't really heard of that being an issue on the newer stuff (2005 +) and certainly not at such a low mileage.

 

My guess would be that its just damn cold! Try to let it warm up a bit more before you drive away , and try to keep your foot out of it until everything has had a chance to get warmed up.

[Maine-iac Subaru]

I have a winding noise from my center console this winter when the temps went below 20 degrees. It seems to becomeing from the rear drive shaft. The noise starts after 10mph. I thought it was just the cold, but we've had temps back in the 40's last week and the noise is still there.

[Fairtax4me]

Probably the carrier bearing on the driveshaft. They don't last forever, and bearings don't like the cold.

 

Worst case Ontario...