Doing a rear main seal job on a Duramax 6.6L diesel engine? This specialty tool (a J-44642 alternative) is absolutely essential to do it right. The rear crankshaft seal on these engines is a two-piece design that seals both the engine block and the crankshaft itself. If it's not installed perfectly straight and to the exact correct depth, it will leak. This two-piece tool mounts onto the crankshaft and applies even pressure to both the inner and outer seal bodies, pressing them into place simultaneously. It also helps install the wear sleeve properly without damaging its lip. Using this tool is the professional way to ensure a leak-free repair on your 2001-and-later GM trucks (2500HD, 3500, GMT800 platform) with the 6.6L Duramax. It's made from quality steel and machined to precise specs. If you're tackling this job yourself, this tool is a must-have to avoid doing the job twice.
