I re-did my servo o/D-rings this weekend. I bought the seals and gasket at Transtar (Grand Prairie, Texas, 972-642-7575,
www.transtar.com) individually so I didn't have to buy the whole rebuild kit.
Transtar's part numbers are K3435L (improved D-ring seals) and 13708 (servo cover gasket). They also have the filter and pan gasket if you need those; I don't know if their filter is the improved type as opposed to the screen.
We were having infrequent failures to go from R to D (RPMs rose but the car wouldn't move for a minute or two), and a rarer failure to accelerate from a standing stop within a few minutes of backing up. The vehicle runs fine after the replacement, as it did 99 percent of the time beforehand, so I guess we'll have to wait for cold weather to see if the problem is gone.
I did not see any obviously failed/failing parts while I was in there. The O-rings looked fine. I do not know what causes the failure mode of this servo. There were four small metal irregularities on the rim of the larger, lower disc part of the servo, corresponding with openings in the servo housing. Hard to imagine this was enough to hang up the servo, but I took the roughness off with a sanding sponge anyway. The metal is softer than you might think, so sand conservatively and use fluid to cushion the movement.
Here is one DAMHIK if you're planning to do this yourself: Buy two of the seal kits. They are dirt-cheap (couple of bucks, really), and if you're as clumsy as I am you may break one of them trying to get it on straight. I ended up re-using the smaller O-ring because I was working on Sunday and my wife needed the car the next day. So if the failure crops up again, I'll have a pretty good idea where to look. :-(
Also, I put a drain plug in the transmission pan while I was at it. Auto-parts stores carry them. I put it right in the middle of the pan's low point, below the filter, and it didn't foul anything upon re-installation. I guess an easy way to test that would have been to put the drain's retainer nut in the pan, hold it in place with a magnet on the outside, then put the pan in place sans gasket. Funny how I never think about these things at the time.
As a final touch I stuck a big old honkin' magnet on the outside of the pan. We'll see what it attracts.