MN3 is a 4T65-E, MH1 is a 4T80-E, here is the difference, this is the 4T65-E, A torque converter with an electronically controlled capacity clutch (ECCC)
This transmission is equipped with an ECCC. The pressure plate does not fully lock to the torque converter cover. Instead, the pressure plate maintains a small amount of slippage, about 20 RPM, in SECOND, THIRD and FOURTH gears, depending on the vehicle application. ECCC was developed to reduce the possibility of noise, vibration or chuggle caused by torque converter clutch (TCC) apply. Typical apply speeds are 49-52 km/h (30-32 mph) in THIRD gear and 65-73 km/h (40-45 mph) in FOURTH gear. Full lockup is available at highway speeds on some applications. This is a 4T80-E, The 4T80-E is a fully automatic front wheel drive electronically controlled transmission. The 4T80-E provides four forward ranges including overdrive. The PCM controls shift points by means of two shift solenoids. Three gear-type oil pumps supply the oil pressure. The PCM regulates oil pressure by means of a transmission pressure control solenoid. The PCM controls the shift schedule and the TCC apply rates. Many sensor inputs also influence the shift schedule and the TCC apply rates. This difference is how the torque converter locks up.
Monday, August 31st, 2009 AT 6:10 PM