|
the age old auto transmission coasting debate,
There are plenty of threads on this one but here is my understanding of auto transmission coasting.
The general check people seem to do is to check if their car can be flat towed (towed by a truck with all 4 wheels on the ground compared to just the back 2 wheels). If the car can be flat towed then there is little risk in coasting in neutral since flat towing is basically coasting in neutral.
People are generally concerned about a lubrication issue, with the transmission unpowered some people believe that the oil pump isn't pumping much or any oil in the transmission which will cause gradual damage to the transmission.
As for my own experience, i have been neutral coasting for maybe 6 months now and i have had 0 issues, i pulse and glide (glide in neutral) then pop it back into gear after reving the engine to rev match.
I also have recently installed override switches for the torque converter lock up and the gear selection solenoids. With the torque converter lock up control i have little worries about shifting back into gear when coasting because i just unlock the torque converter shift into drive (the slush box takes up the slack i believe without any stress or damage) the engine naturally matches RPM when i put the gas pedal down a bit then i lock up the torque converter and keep driving. Its only an issue when i forget to unlock the torque converter when i coast down to lights, i pop it back into gear and the car has stalled out once or twice.
Regarding going back into drive while still moving at high speed, when i didn't have override control of my transmission i did have some issues if i was traveling at around 60 mph, if i went back into drive without rev matching well the transmission would shift down a gear and rev really high.
|