Shifting Concerns for the Six Speed Automatic Transmission on Mercury Montego

The 6-speed automatic transmission used in the Mercury Montego from 2005-2007 is known for issues with harsh shifting, especially while the transmission is slightly warmer than normal operating temperature. This is accompanied by slight transmissionslippage, and is common with this transmission in various makes and models.

The transmission software sometimes causes the slipping and harsh shifts, but in other cases the valve body is to blame.

To remedy the situation, the manufacturer of the transmission has issues various software updates, but in some cases a valve body replacement or transmission rebuild is required.