Hello All,Don Verity is absolutly correct! New Tranny fluid is the most highly detergent lubricant available.for example, when you spill some ATF on a dirty garage floor and wipe it up, you have a fairly clean spot where it was laying.Therefore when you do a fluid change, it is important to"clean" the trans before putting in the new ATF.Sludge and Varnish caused by heat (and trannys get hot) tends to build up on all the internal parts and the trans casing.The best and easiest way to do this is to flush the entire system with a detergent chemical that is a non-solvent. and then replace the old fluid with the new. This can be accomplished by looking for a local service center that has a "WYNNS" trans-serve machine. This is the only trans service that is approved by ALL the major auto manufacturers. BUT please take note that they do not suggest doing this to vehicles that have not been serviced for 60,000 or more miles.There is alot more to discuss about trans flushing and anyone with a Wynns flush machine could probably help you answer flushing questions. If anyone has any questions about this, feel free to email me. Oh, by the way,I am a certified lubricant specialist and regional manager for K-CEE distributing" Wynn oil Co." 300ly, Larry Meixner-----300G [Non-text portions of this message have been removed]