Aahhh yes, the infamous Killer Dowel Pin (KDP) found in First Gen `89-`93 Dodge Ram Cummins 5.9L equipped trucks.

Ever wonder what the Killer Dowel Pin would do if you let your truck run for nearly 300k miles without the kit?  Well, I bought my truck with 292k on the odo and drove it for five thousand more, all the while feeling unsure of that killer dowel pin inside the timing cover.  Had it already fallen out?  Is it even worth worrying about?

Front of First gen 5.9L Cummins, with idler pulley, crank damper/pulley and cover bolts removed.

The answer is:  In my case, Nope! My truck didn’t have any problems with the killer dowel pin.  It was still nicely seated in the bore of the engine block, and well behind the interior surface of the timing gear surround.

Clear photo indicating the location of the Killer Dowel Pin and bolt location used to install the kit.

The photos in this post represent my truck at the 297k miles point in its life.  The engine is original, stamped 5/93 on the data plate.

Close-up of Killer Dowel Pin and bolt; bolt is still installed.

As a part of my Dually Crew cab to Cummins conversion, I  ordered the Killer Dowel Pin Kit from TST Diesel Products.  It seemed to be the appropriate kit for what I was trying to do, including a tube of silicone sealant, the longer bolt, the pin stopping piece, and instructions.

Killer Dowel Pin and original bolt removed.

This post explains the photos I was able to take during the process – multiple web sites list the instructions, or you’ll find instructions in the kit.  The bottom line is that you will see a dowel locating pin next to one of the bolts in the upper left section of the timing gear cover.  It is to the left of the mesh point between two larger gears and to the right of the idler wheel (removed from the front of the block in these photos).

Another photo showing the killer dowel pin and the bolt hole. The bolt holds the timing casing to the engine.

You will have to remove your crank pulley from the engine – this required a ducks foot puller (a.k.a steering wheel puller) or a bearing puller to remove.  Be sure to note where the phase notches were relative to the bolt holes!

Comparison photo - original bolt on left, killer dowel pin kit bolt and pin cover on the right. Photo taken with bolts sitting on the frame of the crew cab.

Once the cover is off, just remove the existing bolt, clean the threads and the new bolt thoroughly using solvent, and then apply threadlocker and the blocking tab to the new bolt. Install the new bolt with the blocking tab covering the killer dowel pin. Tighten bolt to spec.  Then cleanup, remove old gasket and re-seal the cover.

Removing the metal-composite gasket from the cover. Note that the creamy - beige or dingy yellow color is the color of the engine before the dark gray or black paint was put on the engine.

Replace the crank pulley in the same orientation relative to the bolt holes as when you took it off.

The Killer Dowel Pin kit is tangible insurance against a possible failure.  I may have been lucky,  but I cannot disupute the fact that the problem could occur. It has happened to others – just read the forums!

Setting the gap on the magnetic pickup for the speed indication. A small set of feeler gauges seemed to work fine for this.

I suspect that various engines got drilled with a bit or reamer that was large when new, causing the dowel pin to not be as snug of a fit as when the bit had been worn somewhat.   That or the manufacturer selected a fit and tolerance which was not quite tight enough.   Either way, my truck DID NOT have the problem, even after 297,000 miles on the odometer.  I hope yours has held up just as well.  My Recommendation – Fix it; because I would never wish such a failure on anyone.