I'm working on the front suspension of my 240 and last night I tried to use a special tool from IPD to remove the top (22mm) nut from the rod of the strut cartridge. Instead of loosening the nut I was only able to bend the wrench. But I am not here to knock this product. Just to report my experience using it and offer a possible reason for it's failure.
I first tried the wrench by itself. It was obvious I was not going to loosen the nut this way. But there is a square 1/2" drive at one end so I decided to use a breaker bar. The only problem with this is the hole in the IPD wrench is not square with it's handle. It's 45 degrees off. This causes the breaker to be at that angle to the wrench. I was using a large adjustable wrench on the flats of the rod. When I exerted some force on the breaker bar the effect was to slightly bend the specialized wrench. So I removed the breaker and used the ratchet handle with a 2' length of pipe over the whole apparatus. I succeeded only in bending the wrench to the point where it is pretty much useless as is.
I believe the wrench should work under normal circumstances. The nut is intended to have only 15 ft lb torque. I am supposing that the existing top nut was over tightened by someone who previously serviced the car, probably by wailing away at it with an impact wrench. I don't know that for sure but I'd like to give IPD the benefit of the doubt as I think this is a procedure where some mechanics get a bit carried away. I did leave a message via the IPD website and suggested that the handle of the wrench could stand to be stronger. I am not the only one who might encounter this condition. It makes no difference since I intend to keep the wrench. A friend of mine should be able to straighten it and strengthen the handle.
I may yet have to use an impact wrench to loosen the damn nut. But under no circumstances will I use one to reinstall the new insert. Air tools are nice but not for this application.