I have a 2002 Monte Carlo SS 3.8 liter non supercharged, and was wondering if a transmission from a 2002 Buick Century 3.1 liter transmission would be compatible with my car. I know they have the same transmission but I'm not sure about the gear ratios.

 

The gear ratio for the Monte is
1st 2nd 3rd OD Reverse
2.92 1.56 1.00 0.70 2.38






The gear ratio for the century is


1st 2nd 3rd OD Rev
2.92 1.57 1.00 0.70 2.38


The only real difference I see is second gear in the century being 1.57 where the monte is 1.56.


The final drive ratio for the buick is 3.05:1
The final drive ratio for the Monte is 3.29:1


so yes there would be difference and you would probably need to have the computer reprogrammed for the new ratio, although it may work, it would probably be better for you to get a tranny from the following cars to make it easier


1997 Pontiac Grand Prix 3.4 DOHC V6
1997–2003 Chevrolet Lumina/Monte Carlo V6 3.4 L/3.8 L
1997–2003 Chevrolet Venture V6 3.4 L
2000–2003 Chevrolet Impala V6 3.4 L/3.8 L
1997–2001 Chevrolet Lumina/Monte Carlo V6 3.1 L
1998-1999 Oldsmobile Intrigue V6 3.8 L
1998-2003 Pontiac Grand Prix V6 3.1 L/3.8 L
1997-2004 Pontiac Grand Prix "GT" 3800 V6 (L36 Motor)
2006-2007 Chevrolet Malibu (SS Models) V6 3.9 L