I am in the process of removing the 30mm nut from the transmission rear case housing on my 1994 Mercedes E320 wagon. Since I will be removing the nut while I am underneath or bottom of the Mercedes, I will be using a 30mm deep impact deep well socket on the electric impact tool. Should I use some kind of rope to help support the weight of the electric impact tool (it is quite heavy) while trying to remove the nut to make sure the electric impact tool is straight into the nut to avoid stripping the nut? The rope will go through the hole of the gear shift housing that is already removed and I will attach/tighten the rope to inside the area of the console/ passenger seat. That way, it will take the weight pressure off of me while trying to remove the 30mm nut from the transmission rear case housing and hopefully straight into the nut solidly to avoid stripping the nut. The nut itself is quite small in depth due to its design (12 point).

Also, what gear should be on the transmission before removing the nut without damaging the transmission? Park, reverse, drive, or neutral? If I put the transmission gear in neutral, I wil be placing an extension socket through one of the 3 holes of the output transmission flange/yoke (that is where the flexi disc pads goes in) to stop from moving freely and lean against the undercarriage body.

Any comments, feedback/advice is greatly appreciated.