Note: Vehicles equipped with all-wheel drive manual transmission. Under cold and humid conditions, frost may form at the transmission oil level gauge (dipstick) where the breathing mechanism is incorporated. This could cause pressure to build inside the transmission case which in turn could push out the oil seal. Subsequent oil leakage could result in burning of transmission components and possible loss of control due to wheel lock-up. Correction: On vehicles with an all metal type dipstick, the oil level gauge tube will be modified and the dipstick will have a spacer added. Vehicles with a plastic dipstick will have a modified type dipstick installed.
When the vehicle is driven continuously under extremely cold temperatures (-22 degrees f.) and high humidity weather conditions, the transmission breathing (air) vent can be blocked due to moisture freezing at the oil level gauge. If this occurs, pressure inside the transmission case will increase and push out the rear oil seal, causing transmission oil leakage. The lack of lubrication can burn the internal components of the transmission, cause the transmission to seize and the vehicle to come to a sudden stop.
出典：NHTSA（米国、パブリックドメイン）、カナダ運輸省（Open Government Licence – Canada）、DVSA（英国、Open Government Licence v3.0）、RappelConso および EU Safety Gate（フランス、Licence Ouverte 2.0）。