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Retainer Bolt for the Killer Dowel Pin
Using a jig to install a bolt in the timing case to keep the KDP out of the gear train

Visit Geno's Garage
for Truck accessories.
Geno's Garage Truck Accessories

The right thumbnails were from John Strenkowski's photos.
Curtis Harris posted a repair page with photos and details.(=5)

Genos Garage has a KDP kit that includes a KDP retainer tab, and crank seal, and gasket material.
'89-'93 12V DODGE and '98.5-'02 24V DODGE      '94-'98, 12V DODGE

KDP location
"A" on bboxall's photo is the KDP hole
Jig components Drill jig components. You only need to supply the bolt, and drill.
Jig installed on gear housing Drill jig installed on the timing case.
Drilling the bolt hole Drilling the hole.
Bolt installed - outside view with timing cover removed 1/4 -20 by 1" flathead hex bolt installed. Case cover was removed for the photograph.
Bolt installed - inside view with timing cover removed Bolt installed. Case cover was removed to show how the bolt keeps the KDP from escaping..

CPFF's Instructions: Using The Drill Jig To Neutralize The Killer Dowel

Loosen the fan (1 7/16” wrench, Left Hand Thread) and remove the radiator overflow bottle. On my ride the Horton fan and shroud must come out together as one unit. If you can get your fan out past the shroud, do it now. It will save you time. If not, continue with the following: Release the windshield washer bottle on the driver’s side. Unbolt the radiator shroud. Push the top of the shroud towards the motor and pull the fan out between that and the radiator. Move the shroud from side to side to sneak the protruding ears past the radiator hoses. To help with this, bend the top center of the shroud toward the motor-this makes the shroud a little narrower.

Now remove the serpentine belt. Remove the two bolts that hold the alternator on. The bottom rear nut is 15mm, the front bolt is 13mm. Without disconnecting any of the wires, set the alternator up on the rubber intake hose. Remove the 6 bolts that hold the fan pulley on and then the 4 that hold the fan mount to the block.

Put a shop towel over the top of the bottom pulley, then clean the area to the right of where the fan mount was located. (That’s the area where you are going to be drilling.) Remove the 2 bolts from the front cover, put the drill jig on and replace the bolts. Go underneath the truck and hook the regulator to the breather hose. Set the regulator to a maximum of 2 lbs.

Using a low-powered drill-such as a cordless-put the smaller of the two bushings in the jig and drill through the casting with the drill provided. The aluminum casting where you are going to be drilling is approximately ½” thick. The stop on the drill is set at 1”. (When you go through the aluminum, if the drill does not go freely to the stop, then you MUST remove the cover because your dowel is already part way out. With the cover off you can drive the dowel back into the block and then continue with counter sinking and tapping.) Once you have this hole through you can increase the flow on the regulator several more pounds to help clear the chips.

Alternatives for those with no regulated air supply:

If you do not have a pressure regulator, but have an air supply, you can do the following: Get a long piece of rope (clothes line), wrap a paper towel around one end and with a screwdriver force it into the breather pipe. Tie the other end to your steering wheel. Remove your oil filler cap, wrap a shop towel around the end of your air nozzle and hold it against the filler hole. Blow only enough air into the motor to equal about two pounds pressure. (Keep the shop towel loose enough so you will not create a dangerous amount of pressure if you get carried away.)

If you do not have any air supply, you can do it this way. Drill only a ¼” to 3/8” deep in the casting. counter sink the partially drilled hole. Fill the drill with light grease and drill the hole the rest of the way through. Clean the hole out, fill the tap with grease and tap the hole. If you have a way to rotate the motor by hand, (by turning the balancer, etc.) do it between drilling and tapping so any chips that do fall on the gears inside are not all in one spot. A few stray chips spread out inside will not hurt anything.

Comments collected from several TDRoundtable threads:

radixr: When you are performing the dowel pin fix, DON'T pressurize your crankcase system by plugging up the breather tube. You can pop the tappet cover gasket like I did and spend big bucks pulling the injection pump to replace it. Just a word of caution.

illflem: I saw no reason to remove the fan shroud, washer & coolant bottles, so I didn't, it was no problem. If you remove the alternator before the pulley and fan mount it is easier to get your hands in. Also, if you move the fan downward it is also out of the way, there is no need to remove it totally.  My air pressure regulator had a piece of 3/8 id hose on it, a perfect fit on the dipstick tube rather than climbing underneath to the blowby, just pushed it on. No need to worry about over pressure because the excess air comes out the blowby tube, I think only a couple of chips may have fell in when the drill popped through all the rest blew out, I can live with that. Check that you have enough pressure by unscrewing the oil fill cap, enough to lift the cap an inch is plenty. There is no need to use grease or a screwdriver in the hole. Of the two jig fixes that the pin was out enough to stop the bit from penetrating all the way we still completed the entire countersinking and threading procedures but had to remove the cover to pound the pin back in. There were absolutely no chips inside the case.

1) Remove the fan hub. This is best done by using a long drift placed on the right side of the nut flats and giving it a good whack with a hammer. You can then remove the fan by holding the pulley with a pair of large water pump pliers while turning the nut clockwise with a 1 7/16" open end wrench. Spin the fan off and lower it down out of the way, no need to pull it out. ***Note: the jig now comes with the fan wrench and a pulley holder.

2) Crack the six bolts (10mm) on the fan pulley; do not remove them until the belt is loose. Belt is loosened by inserting a 3/8" square drive ratchet in the tensioner arm and turning counter clock wise. A cheater bar helps. Remove belt from alternator.

3) Remove alternator top two bolts first, 10mm and 13mm, nuts are welded. Now when you go to remove the bottom bolt (13mm) you can push the alternator down, this will make the 15mm nut on this bolt easier to see. Set the alternator back towards cab, do not remove wires.

4) Remove the six bolts on the fan pulley you cracked earlier, they should turn out with you fingers. Remove the 4 bolts (10mm) that hold the fan bearing mount. Notice that the bottom bolt is longer and the far left bolt holds down a wire clamp, remember this for reassembly. Remove mount. (The wire held by clamp you just removed can be pulled forward, toward radiator, so the drill can go behind.)

5) Clean the gear case side that was under the fan mount with a rag. Remove the two case bolts (10mm) adjacent to the case curve and attach the jig with them. It will only go on one way.

6) Remove the dipstick and slip the hose with the air valve over the dipstick tube. You can turn the air on quite a bit without danger of over-pressure, the excess will flow out the blow by tube.

7) Drill, countersink then tap the hole using the appropriate bushings and a cordless drill. When tapping turn back the tap ¼ turn for every ½ turn forward. You will hear the airflow slow if you allow too many chips to accumulate in the tap.

** If when drilling the hole the bit doesn't go in all the way to its stop, the dowel pin is coming out. You should still countersink and tap. A short bolt is provided with the kit to plug the hole if you don't have the new seals, gasket and time available. You will need to remove the cover and pound the pin back in ASAP, there is no way of knowing how far out the pin is, it could fall out tomorrow. After the pin is pounded back in, replace the short temporary bolt with a long one. **

8) Blow excess chips away from the pulley and belt. Remove the jig. Remove the air valve and replace dipstick. Insert the bolt using red Loc-Tite, do not over tighten, you are going into aluminum.

9) Reassemble everything using blue Loc-Tite, use anti-seize on the fan hub. You will not be able to tighten the pulley bolts easily until the belt is installed; it keeps the pulley from rotating. The easiest way to replace the belt is to put it though all its pulleys, turn the tensioner then slip the belt under the idler that rides on the back of the belt. Replace fan, hand tight is fine, the spinning will tighten it.

10) !MOST IMPORTANT! Thank John (CPFF) how ever you feel is appropriate, without his work on the jig the job would've been much more difficult.

HEMI®Dart: I can pull the viscous clutch & engine fan out as an assembly without removing the shroud. As long is the cooling system is not pressurized the top radiator hose can be pushed towards the engine to clear the big hex nut. Bring the fan & clutch up on the left side of the radiator (standing in front of the truck). Push the top radiator hose back out of the way towards the engine using a big screwdriver, small prybar or your thumb. Then gently pull the assembly up thru the opening . The big hex nut will rub the top radiator hose, but there's enough room to clear it.

SlyBones: When I did mine I did the countersink first. After seeing the jig and how it works, and how tight the tolerances were on those pieces, I didnt think it was a problem doing the countersink first. No hole for shavings to get into at this point.

amsoilman: When you drill the hole, the air pressure will force most of the metal filings out, but you will most likely need to use a small screw driver or something to reach in the jig hole to move them around enough so the air pressure will force them out. Also I like to fill the drill bit with grease before drilling,tapping and counter sinking as well. As far as the air pressure is concerned, jut don't apply too much! When you hook up the air line, turn your regulator on the compressor down till there is very little air coming from the end of the hose. Then take you oil fill cap loose to see if you are getting much pressure buildup. You don't want alot of pressure building up in the engine.

baby.driver: These are notes I made after using the jig

Paragraph 1 A small shot of WD40 goes along way to getting the fan hub nut loose. Then tap the wrench with a hammer, clockwise as you face it, and, eventually, it will come loose.

Paragraph 2 If you have a thin 10mm combination wrench, removing the six bolts on the fan pulley are unnecessary. Fit the wrench to the bottom right bolt and go for it. Then use a socket on the other three.

Paragraph 3 The drill jig mounting holes are slotted. Mount the jig pushed to the right so the bolts occupy the leftmost space in the slots. This will help when it is time to countersink the hole.

We don’t have a regulator. So after placing the fitting in the breather hose, I took the dipstick out and loosened the oil filler cap and had my son cycle the compressor on and off (with no pressure in the tank) while I drilled. Worked well, just enough pressure to blow the chips out.

Repair facilities with KDP jigs:

Photos and story of KDP damage