The rear crankshaft seal on Gen V V6/V8 engines is installed in reverse to Gen IV engines, and existing installer GM-41479-B will not fit the new seal. GM-41479-10 is an adapter that fits new seal, and is used with previously essential GM-41479-B to install the seal correctly, without having to remove the rear cover. Rear cover removal requires removing the oil pan. The new seal and GM-41479-10 are placed onto the rear of the crankshaft and piloted into the bore. GM-41479-B is attached to the crankshaft, and used with GM-41479-10 to seat the seal. Unapproved methods will damage the seal, cover, or crankshaft.