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Discussion Starter · #1 ·
Killer dowel pin and the fix

article from diesel power mag

When it comes to diesel-truck lore, there are few things that are more aptly named than Killer Dowel Pin Syndrome. It's a problem that was initially reported on Dodges with the Cummins 5.9L from '89-'98 1/2 and is something that can have catastrophic results. During engine assembly, a steel dowel pin is pressed into the block to precisely locate its timing-gear housing. The problem? Over time, vibration can cause the pin to work its way out, and because it's made of steel, there is no working its way through the engine. It becomes the dowel pin of death.

the pin as you hope to find it





There are a few things that can happen. Option number one: you get extremely lucky and the pin falls through the maze of cam, crank, and injection-pump gears and lands harmlessly in the oil pan or on the bottom of the gear housing-and nothing happens. Total cost for repairs: $0.

Option number two: the pin falls, and it comes in contact with the cam gear and smashes into the gear housing on the front of your engine. When this happens, it is steel versus aluminum-and steel wins out. The housing will crack open or lose a big chunk right where the dowel pin was forced into the housing. If this happens, you'll wake up the next morning and notice the Exxon Valdez in your driveway. Your total repair bill, including labor, will be approximately $1,000.

Option number three is the killer: the pin falls and munches up the cam gear or breaks it off completely. The valves will then smack into the pistons, creating a junkyard in your combustion chambers. Scraping metal doesn't work nearly as well as #2 diesel, and this can take out your heads, valves, and pistons-and possibly your engine block, making it impossible to overbore and rebuild. If this happens, there are almost no parts you can salvage, and your only option is to either to sell the truck for parts or pick up a new engine to the tune of at least a few thousands bucks. When option number three happens, you'll be left stranded on the side of the road.



Our '97 Dodge Ram cost $5,000, and we were really worried about option number three because we knew buying another truck might be a cheaper option than getting it fixed. While it may only happen to a few percent of Dodges, the killer dowel pin (KDP) can strike at any time, which is a huge worry for those using the truck for a business or driving long distances.

There are a dozen companies out there selling KDP repair kits (approximately $50) that consist of a new bolt, gaskets, and a tab to hold in the dowel pin so it can't work loose. The labor involved takes about two to three hours for a shop or about an afternoon if you are mechanically inclined and can do the repair in your driveway.

Basically, you have to remove all accessories from the front of your engine so you can get your timing-gear cover off, put in the dowel-retaining tab, then put everything back on. It's labor-intensive but certainly not too difficult. We meant to do this ourselves, but the narrow streets of Venice, California, are the only space we have to work on our truck. Finally, we realized that $200 of shop labor was better than the total loss of the truck and took it to Redline Diesel Performance in Corona, California, to have the dowel pin fixed. Now we can sleep at night.



The killer-dowel-pin repair kit consists of a gear-cover gasket, a new crank seal, and a KDP tab (arrow). Most kits also come with installation instructions; our kit from Piers Diesel Research had instructions that were accurate and well-written.
First, drain some coolant out so the upper radiator hose can be removed and the fan and shroud can be taken off. Later, this can be reused as long as you store it in something clean.
This is what needs to be removed to access the KDP. It's not too difficult, but there is labor involved.



 

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Discussion Starter · #3 ·
if yer dowel pin falls out you will most likely bust the case right here




 

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Is there any mileage range that this can happen at? I recently just installed a 92 6 Cyl in a Jeep J20 pickup with 220K and need to pull the cover off and check my pin.

I see that some kits come with a new longer bolt, is this necessary? I can make my own tab, just wondering if the retaining bolt would be long enough?

If the pin is sticking out can it just be removed or is it necessary for it to be tapped back in.

I have also heard of people using a punch and rounding over the edges of the hole to prevent the pin from coming out. Is this a recommended solution? or considered "jerry riggin"....


Thanks

Joe
 

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for what its worth 4BTs typically do not have KDP issues, they use a slightly different design aka the "bent tab" design for people who are still insistent on doing it (not a bad idea and I plan on doing it just in case). This is the design of 6BTs that very seldom if ever had KDF issues. For what its worth...
 

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Discussion Starter · #7 ·
If you have 220k with no issues then yer prolly OK......but who knows fer sure.............I myself would pull it apart and tab it...it aint real hard and its a good chance to get in there and check some thing out........real good chance to advance some timing too..the easy way

the pin is very hard so a punch will only be so effective........tab it IMHO

I buy the tab kit complete with tab, new longer bolt and a new seal..........just do it baby

I am unaware of the dowel pin arangment with the 4bt so I cant comment much on it
 

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From everything I have read on DTR, the KDPs usually show up roughly between 200-300k. If you have a bit over 200k, I would do it NOW. Its up to you, and how handy you are and how much convenience you want, but I'm doing it to my 4bt "just in case" and making the tab myself. I did this to a friend's truck, and it worked fine. His nose was off because of accident issues, and he had low mileage, so we didn't do the seal...just pulled the cover, used a fender washer to make the tab (cut it down), and used black RTV to seal the front cover. I bought a new seal for my 4bt (along with rear seal and valve cover gaskets) but will be using the fender washer. I don't see the need to pay $20+ extra for a tab over what the seal costs, and a longer bolt isn't needed to install a 1/32" thick tab.

Jim
 
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