John Deere 445 Transmission Oil Vent leak at 0 degree F., Cold Weather, AM878422

Observed transmission oil filled with air bubbles leaking on the rear right side tire at a fast rate after starting up the John Deere 445 to do some snow plowing in 0 degree F. temperature. The plow was slow to move up. Click on "Show More" below for more details.

Moved the John Deere 445 from the pole building to a heated garage. Removed rear wheels, seat, rear fender and gas tank. Observed a lot of oil around the transmission vent cap which is located on top of the hydro-static transmission.

Replaced the transmission oil filter (AM116156) with a Napa FL7103 and replaced the transmission oil with John Deere Low Viscosity Hy-Guard.

The previous transmission oil may have had 500 hours of use. The transmission oil was also on the low side due to previous leaking at cold temperatures. The low transmission oil may have been a factor for the air bubbles observed in the oil as it was leaking onto the floor. The transmission oil leak was like a kettle on the stove boiling over with foam. The transmission vent part number is AM878422.

Currently no more transmission oil leaks but I still need temperatures down to 0 degree F. to fully test the solution. I will update later.

Update March 5, 2015: Temperature was -6 degrees F this morning and no oil leaks observed. No more transmission vent oil leaks since transmission oil and filter were replaced and used the John Deere low viscosity transmission oil :)