Cummins Fatal Flaw Are Two Things That Could Be Killing Your 5.9L Right Now – Here’s How To Fix Both
Cummins Fatal Flaw 1: The Killer Dowel Pin
The first such weakness affects 5.9L Cummins engines manufactured between 1988 and 1998 ( 12-valve Cummins engines used in Dodge Rams). These engines feature a steel dowel pin that locates the front timing gearcase. Over time, this steel dowel pin can wobble out due to the constant heat cycles and vibrations of the engine. If (or when) the dowel pin works its way completely out, it falls into the timing gearcase.
When the Dowel Pin Falls
Cummins Fatal Flaw 2: The Weak 53 Block
For a KDP repair, most of the front of the engine needs to be disassembled to gain access to the timing gearcase. The fan, shroud, overflow bottles, balancer, and lower pulley all need to be removed. With the front of the engine stripped, you can install a small metal tab over the dowel pin to keep it from rattling out. While you’re in there, make sure to tighten up all the gearcase bolts. These bolts loosen over time and will do just as much damage (or more) if they fall into the front geartrain.
Fixing A Cracked 53 Block
Brad Ponci, Ponci’s Diesel Center
So the real question is: Should these problems keep you from owning or buying an ’89 to ’02 Dodge? Our answer is no, they shouldn’t. In the case of the ’89 to ’98 trucks, just get the KDP fixed as soon as possible. On the ’99 to ’02 Dodges, our advice would be to stay away from the 53-block trucks, because not all ’99 to ’02 Dodges used the 53 blocks. If you do find a 53-block Cummins-powered truck, we’d negotiate heavily on price. We’d offer $2,000 to $3,000 less than what you think the truck is worth.