The CTA Tools 6.6L Duramax F/R Crankshaft Seal Service Kit, No. 4044, is designed for servicing the front and rear crankshaft seals on 2001-2016 6.6L Duramax diesel engines. Included in the kit: 3878 Rear Crankshaft Seal Installer to press fit the rear seal, 3879 Front Crankshaft Seal Installer to press fit the front seal, 4042 Front Crankshaft Seal/Wear Sleeve Remover to pull the front seal without damage, and 4043 Rear Crankshaft Seal Remover with jaws to grab and remove the rear seal safely. Installers properly fit the inner and outer seal bodies while the removers use controlled force and jaws to prevent seal and engine damage.