Pontiac Montana transmissions tend to develop slippage over 54,000 miles. The 2007 model year showed slippage after 59,900 miles, while the 2004 tended to slip after 55,000 miles.
The 2003 model tended to slip earliest at 49,900 miles with an average repair cost of $3,800. The 2002 model’s slippage problem starts at 117,000 miles with a repair cost of $311, while the 2001 model’s slippage occurs at 106,600 miles with an average repair bill of $900. The 2006 model tends to shift into overdrive at about 85,000 miles.
The 1998 model tends to suffer total transmission failure at about 68,000 miles with an estimated repair cost of $2,500.