Get it professionally flushed. It's not worth all the hassle trying to rig up something to do it yourself. I have had the Tranny flushed on both of my Sport Tracs (2001 & 2003) and I only paid $85 each, which included 10 quarts of 100% synthetic fluid that was Mercon-V compatible. (Made by Pennnzoil( I had mine done at the local Kwik-Car Lube center. I amd not recommending them or any place in particular, but this is a local shop that does very good work.
The flush machine is just a reservoir to hold the new fluid and as the old fluid is pumped out of the transmission by the transmission pump, it pushes a piston in the machine that pushes the same amount of new fluic back into the transmission.
Don't use any place that won't guarantee their work. A reputable shop will at least guarantee their work for 6 months or 6K miles. That only applies if they did something wrong, like using the wrong fluid, or leaks.
The advantagees of the flush are that it replaces about 98% of the old fluid compared to only about 50%-60% for a conventional 'drop the pan' fluid change. And since it is pumped out through the cooling lines, there is no pan leaks and far less risk of a leak at the cooling line, and even that is easier to fix if it happens.
Any mechanic that says you should not flush the Tranny fluid on an old vehicle is full of BS and does not know what he is talking about. That old wives tale was started because engines that had a lot of mileage without proper oil changes could let go of a lot of hard baked sludge that can severly damage an engine that was running fine while the sludge was stuck to the innards of the engine. The only mechanics/shops that object to transmission flushes are the ones that don't have and can't efford the flush machine.
There are some old die-hard mechanics the feel that they have been changing the fluid for many decades and never had a problems, so there is no need to go with a fancy and expansive flush machine. I accept their opinions and give them the repect that they ar due. I just don't respect so-called mechanics that shoot down newer technology based on myths and lies.
Transmissions are not exposed to combustion by-products and do not form sludge ! Transmission fluid only forms varnish which is more of a sticky coating that can cause valves and checkballs in the valvebody to stick. You want that removed, but flushing the transmission will not remove the varnish. If you flush or change your fluid regularly, you will not have a varnish problem. If you get a flush, do not let them use any kind of solvent or cleaner that they claim will remove the varnish. Most of those solvents will also cause the seals to soften and swell, which will shorten their lives.
A fluid flush is just that, the old fluid is pumped out while new fluid is pumped in. Burnt and worn out fluid is the biggest danger to your transmission. AIt will not hurt your transmission regardless of the age, just as long as only the proper fluid is used and there are no additional and unnecessary cleaner additives used. There is no logical reason to blame a fluid flush for transmission problems that happens later.
...Rich
