1999 5.9 cummins rear main seal replacement

These bolts loosen over time and will do just as much damage (or more) if they fall into the front geartrain. While you’re in there, make sure to tighten up all the gearcase bolts. With the front of the engine stripped, you can install a small metal tab over the dowel pin to keep it from wiggling out. The fan, shroud, overflow bottles, balancer, and lower pulley all need to be removed.

To repair or prevent the Killer Dowel Pin issue, most of the front of the engine needs to be disassembled to gain access to the timing gearcase. Below is a quick overview on repairing the 5.9 12v Cummins killer dowel pin. It takes some time and effort to access the killer dowel pins location.

Don’t let this small dowel pin cause headaches that can be avoided. Otherwise, the 5.9 6BT is an excellent engine. It’s one of the most common, potentially severe problems on the 5.9 Cummins turbodiesel engines. While this last scenario is rare (a hole in the timing gearcase and a big puddle of oil is most likely), it has happened to many Cummins 5.9 12 valve diesel engines, which is how it got its name-the killer dowel pin (KDP). This typically causes the cam to break, the valves to hit the pistons, and the engine to internally self-destruct.

The steel dowel pin could jam between the timing gears.

It could hit one of the timing gears and shoot out the side of the timing case, creating an oil leak.

When the dowel pin falls, one of several things can happen. The dowel pin can: If (or when) the dowel pin works its way completely out, it falls into the timing gearcase. Over time, this steel dowel pin can wobble out due to the constant heat cycles and vibrations of the engine.

The 5.9L Cummins 12-valve diesel engines, manufactured between 19, feature a steel dowel pin that locates the front timing gearcase. 5.9 12v Cummins Killer Dowel Pin Problems

1999 5.9 cummins rear main seal replacement