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I took my timing case off yesterday after a ton of annoying work taking out the radiator because I'm swapping out my IP and I figued I should take care of the KDP at the same time.

Once I got in there I noticed it doesn't look like this picture:



The area where the pin is is actually raised up higher than where the bolt head sits. Is this an updated design or what? I don't think it would be possible to just use one of those egg shaped washers to keep it in. Strange...

The good news is that it is seated in there about 3/8" below the surface so it wasn't even close to coming out. Anyone know whats up with my timing case though?
 

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Not sure about the case but if that boss is raised enough the pin will not have room to come out before it hits the cover. You'll be good to go.
Carl
 

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Not sure about the case but if that boss is raised enough the pin will not have room to come out before it hits the cover. You'll be good to go.
Carl
Not 100 percent of the time! Here is mine that came out of my 91 6BT with the raised shoulder.
 

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Discussion Starter #5
I'm thinking instead of the standard fix I may just TIG weld on a little piece to the timing cover that will fit in the hole and not allow it to come out much like the guys fix the problem from the outside with a screw.
 

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It is a hardened bullet shaped piece of steel .495" in diameter used to locate the gear housing in the proper position on the front of the engine block. Over time this pin manages to vibrate itself loose and work its way back out of the timing case. This time is decreased by increasing vibrations whenever the injection pump is turned up. In most cases it will fall into the timing gears. This usually results in breaking the timing gears, snapping the camshaft in two, and destroying the gear housing by knocking a hole where the debris & pin exit. If you are really lucky it can fall out and just end up in the oil pan or exit through the timing cover as mine did. Here is a link describing a preventive fix for the problem:
http://www.pavementsucks.com/forums/viewtopic.php?topic=70419
 

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any updates on how to fix it with the raised boss?

should i just run a longer bolt and make a tab with a shoulder?
 

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Is this a problem part for the 6bt only or does it apply to the 4bt as well?
it applies to both. i've read how to fix it with the jig, but i would rather do it with the tab. i already pulled my timing cover.
 

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Reference to the attached picture;

The Top Left shot of the Dowel Pin is as I have found on 6B series. Note that the area around the dowel pin is machined flat.

The Top Right shot of the Dowel Pin is what I found on my (5) 4BTA's. Note that the area of the dowel pin is stepped.

The lower Center picture shows the tab I made from 12 ga sheet steel to retain my dowel pins. Due to the thickness of the 12 ga tab, I used a new M8x1.25x20 Bolt which was torqued to Spec with Red Locktite.

Two of my friends have 4BTA's with a Flat area around the dowel pin. I have no idea why Cummins had two different designs on the 4B series timing case cover, but they are out there.

While I had the Timing Case Cover off, I re-torqued with red locktite
all the other timing case bolts. Also did the oil pump. I found all of them quite loose, no where near torque. Also put new front main seals in while I was opened up.

Paul
 

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