2005 Ford Powerstroke - Transmission

[Tom S.]

quote:Originally posted by BethandKevin

Okay, here is what I know for sure. When you purchase a "flush" it really isn't so. It really should be called a fluid exchange. The "flush" machine is hooked in series with your vehicle, outlet line to the machine and machine into the radiator or cooler inlet. Sometimes there is an additive put in the transmission fluid prior to this. Then the vehicle is ran while exchanginging the fluid from the transmission with that placed in the reservoir of the machine. When the reservoir is empty, the process is complete. The convertor gets "flushed" in this manner. It is at this point when the pan should always be dropped after a "flush". The reason being whether you have a filter or not, an inspection should be made for debris. In any event, the pan needs to be cleaned of the debris that is normally left after "flushing" with an additive. One should NEVER "flush" a transmission without dropping the pan. Change the filter without "flushing" ok-"flush" without filter not ok. Exchanging the fluid in this way can and does dislodge debris. When metal is found in the pan, that is cause for concern. Gray matter that is the consistency of graphite is normal as long as the fluid has not turned black. Some companies that supply the additives for "flushing" have a friction modifier which can be added at the end. My general rule has always been, look at the fluid-is it a nice ruby red? Is there sediment on the dipstick (this is the graphite looking stuff in the pan)? Do I have any pan gasket leaks? If all this checks ok, then I do just what is recomended by the manufacturer. In my case, A spin-on filter is recomended every 15,000 miles. I do not have a filter in the pan, only a screen. Also worth noting, does your truck use synthetic fluid. If it does, the period of time between services should be longer. Synthetic fluid does not as readily absorb particulates, it carries it to the filter. All GM vehicles since 2007 use Dexron VI, which is synthetic. I hope to have cleared up some of the mystery behind transmission service.

Kevin is 100% correct. Every trans pan I have ever pulled has had clutch disk sediment covering the bottom. This is normal - the clutches in an automatic trans are designed to slip when changing gears and this slippage causes wear. Some of these particles are captured by the filters (some trucks have more than one!), but heavier particles sink to the bottom of the pan. So if they are heavy and sink to bottom of the pan, why worry about them? Because hitting a bump or chuck hole can jar them loose and into the stream of fluid. Unlike manual transmissions, cleanliness is next to Godliness when it comes to automatics - the cleaner you keep it, the longer it will last and perform properly.