Ivanerol took the other option, which is certainly viable, and even preferable if you do not want to open up the transmission. However, if my transmission is typical, then I think that the risk of other bits failing soon is fairly low.

In my case, except for the bits that has actually failed, the rest of the transmission was like new. Of course, after 19 years and 200,000 miles, the o-rings were as brittle as bakelite and the transmission had a severe leaking problem. After the overhaul, it is as tight as a drum. I am sure that it will now outlast the rest of the car.

If the transmission is coming out anyway, it does no harm to take a look inside to see if the spring container is broken. It is one of the first things that you come to when going in from the torque converter side. It will be really obvious quite soon.

By the way, there are a couple of transmission manuals available on line. The links are buried in the archives somewhere.

There is a manual for the military G-Wagen, with a 722.3 transmission.. This is similar to the 722.4 used on the 190e, but with a stronger, larger case. There are detail inside differences, too. It is an actual Mercedes manual. Some of the tiny bits in the valve housings are a little different, so it cannot be relied on if you forget which bit goes where in the valve housing.

There is a 2000 Mitchell Manual extract for the 722 series transmission as use on a 1996 C220. I did not rely on that one at all.

The Transtec/Corteco site was good for the article on replacing the two hidden large o-rings.

There is also a paper manual available from ATSG (Automatic Transmission Service Group), or Techtran. It was about $45, as I recall, and well worth it. It is hard to read, as the sections are badly titled and in a funny order. It is not always clear which parts refer to the 722.3 and which to the 722.4. The instructions are written frontwards and backwards, so that you go back up the paragraphs when reassembling. However, once you have figured it out it is useful. It contains accurate diagrams specific to the 722.4 transmission used in our cars. It is based on real Mercedes manuals and diagrams. The valve body illustrations are accurate. It shows the changes that were made suring production. I relied on this one the most.

Cheers!

Andrew