The B1 piston assembly is not easy to remove and then reinstall. Because of the length of the two big springs behind the cover, it takes a tool that has a lengthy throw. Some have used valve spring compressors, blocks of wood, and pry bars, and some work, but not easily, because most do not have the necessary travel to move the cover plate back into position, keeping it straight. Watch the video below to see the whole operation by Kent. NOTE: As of September 15, 2025, Kent has added a smaller bolt to accommodate the smaller banjo bolt hole in the 722.4 transmission.
Product Details
Look at the travel required.
Much easier to get it out. Getting it back in without this tool to keep it aligned can be challenging.
Related Products:
722.3 Transmission Overhaul Gasket and Seal Kit
Take a very close look at the picture. These are all the gaskets and seals you will need to replace if you open up your 722.3 transmission that was produced from 1981 to 1995 for all 6 and 8 cylinder passenger cars that had a displacement of 3.0 liters or more.
722.3 722.4 Upgraded B2 Piston Replacement Kit
We are learning, as others are, that these parts are becoming a HIGH preventative maintenance item on these old transmissions. A broken or binding B2 piston causes many shifting problems, and as Kent found on his 300E, it destroyed the transmission.
722.3 Transmission Rear Shaft Nut Removal Socket.
You will need a 12-point DEEP socket. That is the only thing that will work. Most impact sockets are six-sided. The best way to remove this nut is with a big impact wrench with the transmission locked in park. So you will need a quality heavy-duty socket. This one is made in the U.S.A.
722.3 722.4 B2 Seal/Sleeve and Front Pump Removal Tool Kit
We modified this slide hammer puller set in our shop so it will work in removing two key components in the 722.3 and 722.4 automatic transmissions. Getting the B2 piston and sleeve out of the case can be a real bear without this tool. With it, it comes out quickly and easily.