My 4L60e transmission had nearly 80,000 on it ,and was loosing 2nd gear. Its in a 2003 GMC Seirra 1/2 ton 4X4. Most miles where from going to work and back, racing to get my son to baseball games and practice with occasional towing and trips to and through the snow . Anyone with a 4l60e in a truck knows this is a car tranny in a truck , weak sauce. But after rebuilding it with Sonex, Red Eagle, Rabestos z pacs and Trans go Heavy Duty parts .I can now tow with in reason, get to work, run to Baseball knowing my truck can handle all the duties expected of a 1/2 ton truck with total confidence. They also installed a new water pump that was leaking and did a Fantastic job . The build quality is fantastic they got everything done in record time. This truck never shifted this good from brand new, nearly every part has been upgraded way above factory specs. The staff is professional and knows what they are doing at Mr. Transmission of Roseville. Make your life easier, go to them for any transmission problem you may have. Jeff Harper