I bought a 1997 MKVIII last November and I noted this TSB on the MKVIII home page:
           http://www.designpointe.com/LSC/mk8tsb.html
           Yesterday I installed the new shift piston and spring in my car, it took maybe two
           hours.
           A few observations:
           The part number FZAZ-7F251-AA is incorrect on the web site, it's actually
           F7AZ-7F251-AA (seven instead of Z.) The parts cost me $13 from a nearby dealer
           (it turns out the dealer in the next town was a great deal cheaper so markups on
           parts
           differ!) I had also bought a replacement Motorcraft trans filter and an ATSG manual
           for the transmission (I go the manual from JC Whitney and the filter from
           carparts.com)
           What I didn't have, which would have shaved 30 minutes off the job was a honkin' big
           pair of snap-ring pliers. My snap-ring plier set was way too small for the 2" or so snap
           ring that holds the piston cover in place. They worked but not well, the snap ring kept
           popping off of the pliers. Compressing the piston like I did during reinstallation would
           have also helped.
           A small (1/4" drive) 10mm socket and extension is needed to clear the shift linkage 
           when removing the trans pan. I also found that a very large oil catch pan is needed
           (larger than the trans cover) to get the trans cover off without making a mess. I
           made a mess and it took quite a while to deal with the dripping fluid, having a big
           tub to drop the trans cover, fluid and all, into would have saved 15 minutes.

           Once I got the snap-ring out it was trivial to remove the piston cover, piston and 
           springs. My piston / bore was not scuffed (at 55k mi) although it was of the old
           design.
           The guy who posted the TSB had scuffing at 22k mi on a 97 so YMMV.
           The new piston design has more seal area and depth that should make scuffing 
           impossible.

           The piston in question is in the right front (IIRC) of the transmission (from the 
           driver's perspective.) As you look at it, under the car with your head under the trans
           and feet under the driveshaft, it's in the top left corner. the valve body need not be
           removed, just the pan and the piston cover.

           It is rather more difficult to reinsert the assembly against the spring
           pressure. I used a floor jack with a socket and extention to press the piston 
           up into it's bore so I could use both hands to get the snap-ring back in. Had I
           a BIG snap-ring pliers that might not have been neccisary, but maybe it was as I 
           think it took both hands to press the piston in by hand, leaving none to deal with the 
           snap-ring. The trans gasket is reusable and I reused it, no problem there except that
           I untacked too much of the gasket from the trans and had some trouble making sure it

           was back in the right place before bolting up the pan again. Oh, and of course when 
           I removed the filter, the orange O-ring stayed with the trans and had to be pried out 
           before the new filter could be put in. I noticed this when I tried to put the new filter in
           and
           met with some resistance. Happily the old filter was still handy and the lack of the
           O-ring 
           was immediately obvious. It's stuff like this that keeps me out of Quick-lube type
           places,
           I worry that they would have just crammed the filter in with both O-rings in there.

           I'd bought several gallons of ATF which was good as I needed something like six
           quarts to replace the lost fluid (which needed changing anyway.) I'd like to replace
           all the ATF in the thing, as I know how intolerant Ford trannies are to dirty fluid,
           but I may wait for better weather and do that via the cooler lines. I want to switch 
           to synthetic ATF but three gallons of that stuff is enough of a dent to my wallet that
           it'll wait until after the holiday bills are paid, plus some $5/gal Havoline will be 
           good to run in there to dilute the somewhat dark fluid that was in the car when I got it.
           When I get the $5/gallon fluid to run clean I'll put in the $20/gal stuff. Doing it via the
           cooler lines is the only way to change the fluid in the converter too.

           It was nice to get cleaned up and take the Mark for a drive, and note that the trans
           still worked after my upgrade, and nice to have more peace of mind knowing my very 
           expensive transmission isn't going to fail due to a $13 part.

           -Joel Frahm mailto:frahm@jila.colorado.edu