Originally posted by: slag
Originally posted by: rbloedow
Yea, a flush is a little more than the equivelent of an oil change for your transmission. Stuff builds up in the ATF fluid, and usually they'll pull out the magnet at the bottom of the trans to see if there are any signs of trouble.
Whoa nellie.
Not at all true.
A tranny flush actually recycles fresh tranny fluid in the entire tranny and torque converter which replaces 100% of the fluid in the tranny and cleans up deposits in the valve body and other places. Its a 100% fluid change which costs a lot.
On higher mileage cars, it can actually cause premature failure of the tranny if its never been done before.
By contrast, an oil change just changes the oil that is in your pan (which is a large amount), but does not flush your engine with fresh oil at all. Not at all the same as an oil change other than the fact new fluid is going in and its under your hood.
Many places do not even drop the tranny pan on a flush--they just hook hoses up to the tranny cooler lines and flush that way. I'd never get one done unless my transmission was acting up and I had relatively low miles (under 100k). If everything is working fine and your tranny fluid has been changed along with the filter regularly, then this service is normally not needed.