Any harm from turning an automatic upside down?

mtmc

New Member
May 11, 2011
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VA
I have another 4R70W that I am going to put into my mustang. Before I do, I'd like to change all of the fluids, install a front and rear seal, and install a new tranny filter. I figured this would be easier to do outside of the car. Would there be any harm done if I put it on a motor stand, drain the fluids, and flip it upside down to install the filter? Would I have any problems with the steel balls moving somewhere they don't need to be during the rotation?
 
mtmc:

The Auto Transmissions Service Guide (ATSG) booklet shows exactly what you are proposing to do: transmission secured to engine stand and upside down for some of the work. As long as fluid is well drained then you should be able to avoid a big mess, as LarsD menitoned.

The rubber balls are in the valve body an will not come out if you don't take the separator plate off the valve body and turn the v/b upside down at that point. The separator plate holds the balls in the tracks where they should be so you can take out the valve body (as a module) but don't take it apart unless it is right-side up.

Good luck. How about taking some pics of the rebuild so you can write it all up for future reference? If you don't get even a free beer from a grateful StangNet member then at least you will have our gratitude. :D

Chris
 
Thanks for the reply. Do you have any advice for the best way to drain it completely? I'm going to drain it all and put in new fresh fluid. I plan to install a pan drain plug when I put it back together for future maintenance.
 
mtmc:

The 'official' way of doing it is to drop the pan and use a big catch pot under the pan. I forked out for a new FRPP drain pan that has a drain plug (hey, I can't take all my riches with me, can I?) but there are "add-a-plug" kits available or you can weld in a bung for a plug if you are handy with a welding machine.

There is no secret to draining the transmission. ATF will hide in a few spots but you can't really get it out until you start taking things apart. Let it drain for a long time is, of course, one piece of advice. The valvebody will hold up a little fluid (0.5 to 0.75 pints) but that can't be avoided, imho, so just be prepared for it.

I have not rebuilt an automatic so I am far from being an authority on the subject. Check out "Transmissions 101" by Jerry Wroblewski (former Ford Transmission Engineer) in the Tech Articles/Transmissions section of TCCoA.com. Excellent series of articles, including several about building a bulletproof 4R70W.

HTH,

Chris