The front crankshaft seal on Gen V V6/V8 engines is installed in reverse to that of Gen IV engines, and is positioned below the surface of the cover. Existing installer GM-41478-A will not fit the new seal. GM-51091 installs the seal into the correct operating position in the front cover and will also clear the key at the end of the crankshaft. To install, the seal is placed onto GM-51091 and piloted into the front cover bore. The 16 mm rod and hardware from previously Essential GM-41478-A are installed through GM-51091, threaded into the crankshaft, and used against the back of GM-51091 to install the seal. Unapproved methods may damage the seal, cover, or crankshaft, or may not position the seal correctly.