727 Rebuild - Check Ball Question

[Kevin718]

I am in the process of rebuilding the 727 transmission from my 91 GW. After taking the valve body apart, it seems that I have an extra check ball. Here is some information:

As Found:
Check balls in the valve body = 8 (7 small, and 1 large)
Check balls in the transfer plate = 1 (small)

Per Service Manual:
Check balls in the valve body = 7 (6 small, and 1 large)
Check balls in the transfer plate = 1 (small)

The extra check ball is the 4th one down from the top of this picture.



And here is a picture of the separator plate lined up on the valve body. At all places where there is suppose a check ball, there are round holes on the separator plate, so that the ball can actually check. At the location of the extra check ball, there is a rectangular opening.



The extra check ball also did not move freely. I needed to use a screwdriver to pry out this check ball.

So, is this check ball needed? Can I just leave it out in the rebuild?

[CheapJeep]

Now i will freely admit I am sort of talking out of my a$$ here, but this is what I learned replacing my explorer transmission. As the transmission got older and were rebuilt, if there were any service updates on them, the rebuild shops would usually do the updates. But, some were done in the factory as the later transmissions were built.
In my case, my service manual for a 94 explorer showed 4, there were actually 5, and the service updates called to add 2 and move 1.
Also, if there was any kind of shift kit, that might change it also.
For my explorer needs, I found info and parts on Transgo's website. try them for this also. their shift kits are supposed to be pretty good.
the nice thing about doing valve body mods is that they are fairly easy to change out if you screw it up! except for getting covered in tranny fluid
hope this helps at least somewhat.
Scott

[Quibbler]

First off It came from the factory with only 7 check balls. the extra one will be from a shift kit. They basicly use the same vb from the 727 all the way to the new 2006 48re and they have always only taken the the 7 there. Unlike ford that every other year there is a new combo of check ball locations. I rebuild and shift kit 10 of these vb a day at work (95-06). Mine had a check ball in the same spot but it was free to move and pounded away on the two sides (under the small circle). I have no idea why the kit put it there, I never deal with the old school kits. I put it back in when I rebuilt it. I figured it worked when I pulled it It should still work when I put it back ( the older stuff scares me ). Anouther way to check is to see if its been shift kitted, is the valve with the larger circle (throttle valve) will have the top cut off. Finally if your not putting in a newer shift kit, you can turn the pressure up by turning in the adjuster on the pressure regulator spring.

[Quibbler]

I would also take the time to flat sand both halves. Either by a flat bar, or sandpaper on a sheet of glass. a metal seperator plate makes a bad seal over nicks or a warped alum. casting.

[Kevin718]

Thanks for the information. I also became convinced that if it worked before, then the check ball should be reinstalled.

Attached is a picture of the throttle valve (manual valve and kickdown valve also included). According to the drawing in the service manual, it seems that my throttle valve has not been changed. It is also an aluminum valve with a "special coating" that the sm warns against damaging. It says that if the coating is not there, it will cause the valves to stick and bind.

[Quibbler]

You valve looks fine. When they wear out you will see the alum. through the grey anodizing. And no yours is not cut.

When reinstalling. Install Shuttle valve ( spring and 2 retainers and clip) first. Then your 3 gov plugs. Make sure they move freely in a dry clean bore. If not polish with scotchbrite. then flip over and then your shift valve. Make sure they fall freely into the bore and bounce a bit. These are the most important in shift timing.