Transmission fluid flushing

[The_Handier_Man1]

From: Dave1210  (Original Message)
Sent: 8/9/2002 11:54 PM

    I have been thinking of changing the trans fluid and filter and also flushing it. I believe it is a 727 trans. Does anyone have any tips, what type of fluid, how much, and how to flush it? The trans works great and I want to do this because the fluid is most likely old.

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     These transmissions used to call for Dexron as I recall. I knew a man who ran a transmission shop back in the late 70's and early 80's. He used Type "F" in all his rebuilds. He stated he liked the friction modifiers better in the Type "F" or something like that. That's going back a few years when things were simplier before you had all the variants of  Dexron and type "F".
     For anyone that might try to change their fluid for the first time there is a word of caution. The transmission pan is very easy to warp when you reinstall it, even when you do it carefully.  Cousin Eddie

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     I just did this on my ' 71 and it took 4 quarts of oil, when changing the filter. I also would advise you to adjust low and reverse band, and the kickdown band while you have the pan off.  The low and reverse band is inside the pan, and you loosen locknut, and tighten stud to 72 inch pounds, then back off 2 turns and retighten lock nut. The kickdown band is on the outside of trans on the left side (Drivers side), Loosen locknut, and tighten stud to 72 inch pounds, back off stud 2 1/2 turns, and retighten locknut. Reinstall pan and fill with Dexron (4 quarts) and start it up and run it through all drive ranges and then recheck oil level.    Jerry

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     If you have someone to help you, you can change all the fluid in your transmission (including the torque converter).  First, disconnect the cooler line coming from the transmission (the line connected nearest the front of the transmission) at the cooler. Then, put an extension on that line so it can be directed into a large container, at least 3 gal.  From above, someone will have to start the rig and pour transmission fluid into the filler.  I find it is easier if you have a large container of fluid, I use 10 litre jugs of fluid.  Down below, that person will have direct the fluid coming out of the cooler line into the container.  You will be able to tell when the fluid is changed when the colour changes to light red.  Of course, if you are changing the filter and adjusting the bands, you would do that first and add a couple quarts of fluid before changing the rest of the fluid.  I also have found that when changing the fluid like this that the filler takes the new fluid at about the same rate as it comes out of the cooler line.  Then there is little adjustment to be made after.  Just rember to check the fluid in neutral, it does make a difference.         Rick (elandan2)

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     You will need about three gallons of fluid (can be found at Wal-mart in gal. for $4.17) . The best way to change All of the fluid would be to open a cooling line going to the radiator. w/ a clear hose( you can get cheep at a home improvement store)
just force the hose onto the line and the nipple, to see which way the fluid is flowing. take off the end that the fluid is comming out of and put it into a propper oil waste container. Put a funell into the dipstick hole, as you pump out the dirty oil pour in the clean. this way you get out all of the oil out of the tourque converter, and the cooling lines. If you want to change the filter, take the pan off after you have pumped out a little clean ATF. If you only change the ATF in the pan you will be mixing the old and the new and that will cause lots of problems.    macdaddy