Killer Dowel Pin will kill no more!!

[CPFF]

I had been concerned about this for some time now. I have to go on a 3. 5k mile ride soon. I didn't need to go with that "time bomb" under the hood, so I guessed I'd better get to it. After 2 1/2 days of measuring,making and remaking,I finally came up with a tool to de-fuse that "time bomb" positively. It takes less than ten minutes to do - (after you first remove the fan mount and the alternator). Not too much effort for the pease of mind it will give.
CPFF

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CUMMINS POWERED FAST FORD

 

[SRT-6]

What are the details on the tool?

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88 GMC CREW CAB 4X4 89 6BT,NO INTERCOOLER YET,AUTO METER LIQUID FILLED GAUGES,NV4500,NP205,4. 10's,35 BFGA/TKO,6" LIFT,DETROIT LOCKER,16CM,K&N,3. 5 EXHAUST,BD "PRINCE OF DARKNESS"INJECTORS 96 215 hp on the way. J. Mason

 

[PUMPERDUDE]

Yea,lets hear it... . please

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1995 Club Cab 4WD 5. 9 SLT 5 SPEED,CAT IS MIA,TST #6 IS IN THE GROOVE,29. 5 ALJO TRAILING BEHIND.

 

[Bill Lins]

Did you figure out a way to drill & pin the dowel through the cover? I've been wondering if it was possible to preemptively fix the problem in that manner.

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Bill Lins Wharton, TX 98 2500 QC SLT,12 (the CORRECT # of)valves,NV4500,3. 54 LSD,Manik grille guard,Semi-Psychotty Air,Amsoil everywhere, Reading aluminum utility body and bumper,Optima yellow tops- silencer ring & muffler stolen.

 

[CPFF]

NO - I did not pin it. I made a drill jig to tap a hole in the side of the alum. housing for a screw to come out directly behind the dowel, leaving no room for it to get out.
I took some pictures - have to get someone to put them on here maybe.
CPFF

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CUMMINS POWERED FAST FORD

 

[rustnrot]

How did you address aluminum filings getting into the engine? when drilling?

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[Sled Puller]

If your road trip is taking you on I-80 through PA, let me know!


Gene

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1997 Cummins Dodge 4x4 "One Piece At A Time" Bombed & Amsoiled. Amsoil Premiere Direct Jobber, Member of: NRA Business Alliance, GLTDR, WANTED: Wrecked Dodges.
www.awdist.com

 

[RAMalama]

You say you have a fix and you took some pictures that you may post... "maybe"

Throw this dog a bone

Ian.

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'95 2WD 3500 std cab, 4:10, 5spd. 68K miles all towing 14K-lbs 5er. Completely stock but learning...

 

[CPFF]

Ian
I will try to send pictures as soon as I get the patent stuff out of the way.
CPFF

 

[grtescpa]

Originally posted by CPFF:
I had been concerned about this for some time now. I have to go on a 3. 5k mile ride soon. I didn't need to go with that "time bomb" under the hood, so I guessed I'd better get to it. After 2 1/2 days of measuring,making and remaking,I finally came up with a tool to de-fuse that "time bomb" positively. It takes less than ten minutes to do - (after you first remove the fan mount and the alternator). Not too much effort for the pease of mind it will give.
CPFF

Thank you Sir! I to would like to know how you kept the drill fileings out of the engine? Vacuum drilling? Don't keep us all waiting to long with complete details
of your job.

 

[Joseph Donnelly]

Patent stuff??? I hope you aren't going to send storm troopers to confiscate the jig that is in my toolbox #ad
#ad


For those Rammers who need to fix the dowel pin now, so they can sleep better, my jig has a hole in it just big enough for the 5/16 x 18 tap and a sleeve from copper or steel tubing to bush it down to 1/4" for the through drill. The jig bolts down to the aluminum gear housing or the front cover using the two bolts around the dowel pin. These bolts go through the housing into the engine block. The drill goes into the housing at about a 23 degree angle inward from the stamped steel cover surface, and strikes the outside of the aluminum gear housing about 1. 5 cm inboard from the steel cover (the housing is about 3. 5 cm thick)--that is, almost half way along its thickness. This puts the end of a button head bolt or socket head set screw just over/on the dowel pin. I seal and retain the setscrew with red Loctite 271 or equiv. Because of the continued interest in the dowel pin, I have taken pictures and roughed out a write-up for the TDR Tech Topics column for Issue 33 (32 is in press already).

Also, not wishing to worry everyone too much, but in the interest of complete information, there are bolts inside the cover that also could come loose (I have heard of only one such case). Cleaning them and the threaded holes, then using blue Loctite 242 or equiv. might be in order if you take the stamped steel cover off.

If you are very careful to sweep and/or vacuum chips, and use grease on the tap to collect chips, you can probably do the setscrew routine and not get any (or maybe 1-2) little chips into the gear housing if you don't take off the cover. I think a tiny bit of aluminum is better than that darn dowel pin banging around in there, but the ideal situation is to have neither loose inside, of course. The inside of an engine isn't a very friendly environment anyway. For example, Holset tests their turbos by pouring junk through the exhaust side (just in case the factory leaves something in a port, they don't want the turbo to grenade).



[This message has been edited by Joseph Donnelly (edited 04-27-2001). ]

 

['956Wheel]

Joe, If I understand you the drill fixture guides the drill from the outside of the case and hits the pin at an angle... right? Is there a "boss" in the case casting that makes it obvious as to the pins location? I was getting ready to tear the front apart and peen the pins bore so it could not come through, but your idea sounds better, less mess!

Patent! That could take a while... gee thanks! Glad you posted, I just cringe everytime I think that pin could wreck the whole front, and then some... . wait for a patent... MY A$$!

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9535hundred

 

[Joseph Donnelly]

The setscrew comes into the gear case at an angle, meaning the farther inside, the farther toward the block surface. The jig is made up from a piece of 3/16" plate about 1. 5 x 3" cut out to follow the contours of the stamped cover around the bolts, and with a half circle cutout so I could weld on a piece of round steel stock about 1" diameter and 1" long with the 5/16" hole in it. The jig positions the drill/tap guide outboard of the gear case, where the fan hub would be.

The hole in the round stock is at the 23 degree angle to the plate surface. This angle is nice for two reasons: (1) there is room for a drill chuck where the fan hub is normally bolted to the block--if the setscrew went in parallel to the block surface, there wouldn't be room to get an electric drill chuck in there; (2) the setscrew can't back out because the fan hub is in the way, and it can't go in farther because it hits the dowel and/or aluminum gear housing base where it bolts to the engine block. Actually I'd be surprised if it moved because red Loctite is pretty permanent.

As for where the dowel is, look at the pictures on the other current threads. It is just to the driver's side of the fan hub and just inside the gear case wall. It is about 1/2" up from the lower of the two bolts that the jig bolts to. [That is in a vertical direction--note that the gear case itself is going at an angle so the distance along the outer wall of it is a bit more, about . 6"] The jig mounts to two bolts that go through the gear case and the distance between them (center to center) is 1. 7". They are the only two bolts that are that close together on the gear case's cover.

 

[Dieselnerd]

How hard is it to take the stamped metal cover off? It seems to me that if you take off the cover you could drill and tap without making a jig and also catch all the shavings from your work. I realize this would take longer but then you wouldn't have to take the time to make a jig either so it may even out. You could also see if your pin is starting to come out with the cover off. Since I've never had my cover off I may be missing something that makes it hard to do which always seems to be my luck when I think of an easy way to do something. I'm wondering if it's possible to take out all the cover bolts and rotate the cover enough to do your drilling without removing the crankshaft damper and going through the seal routine that seems to be the biggest problem I can see in the service manual. Is there enough "wiggle room" to do that?

[This message has been edited by Dieselnerd (edited 04-28-2001). ]

 

[R.ebel]

Joe Donnelly, Thanks for the tip about the bolts that attach the gear case to the block and the possibility that they can back out. I'll be thread locking mine when I'm in there #ad




On the dowel pin fix, IMHO a simpler method is to install some kind of large fender washer (have to modify one to fit) under the bolt that is next to the dowel pin, this would block off the dowel pin hole opening. For added strenght I'll be fabricating my washer out of some . 063" titanium sheet stock that I have laying around. No need to fabricate a drill jig, no drilling, tapping or the possibility of chips getting into the engine.



This is all theoretical at this point because I have yet to perform this modification. If anyone thinks this is a "bad" idea please speak up, I'd like to consider your thoughts.

 

[Dieselnerd]

Sounds like a great idea to me R. ebel, as long as it's not a gigantic task to move the cover enough to get at the bolt you mentioned. With all of us "gearheads" working on the problem I'm sure we will develop a good long term fix that is also easy to do.

 

[Joseph Donnelly]

Check the picture in the Dowel Pin Pictures thread. If you have the early design gear housing, the gear housing surface at the pin is the same height as at the nearby inside bolt holding the housing to the block. The pin may or may not stick out some from the aluminum housing surface there. You could make a tab if you grind it to fairly close tolerances. I think the bolt can stick out more without hitting the cam gear, but clearance is fairly close. You will need a longer bolt [M8 x 1. 25 x 25 should work], but you could use a grade 9 Allen or something with a smaller head if you wish, using the tab as a washer as well as something to keep the dowel from falling out. The later design housings have the surface at the dowel higher and making a tab would be more involved, with a step in it. You would have to loctite the bolt and design the tab so it couldn't rotate out of position (not too hard to do this).
You can't rotate the cover enough to do you any good for two reasons (1) some of its hold down bolts are under the dampener; (2) the vacuum pump shaft sticks out into the bulge in the cover. You may be able to drill freehand but since you will be coming at the gear housing from an angle, it is hard to keep the bit from skating around--you might be able to centerpunch and then start a hole with a smaller bit first. The angle is fairly important but not critical. You want the end of the setscrew to be near or against the dowel, and to go inside far enough to be over the dowel.

[This message has been edited by Joseph Donnelly (edited 04-28-2001). ]

 

[illflem]

Joseph, since you've done this fix can you give a rough estimate of the time involved?

 

[CPFF]

The 'patent stuff' is all taken care of. The reason I did it is because whenever I come up with a gadget, idea, etc. , I get harassed by the "experts" saying I should have patented it. Although I didn't think this had much commercial value, I looked into it.
I do have pictures of the jig and the process--I don't know how to post them. I can e-mail them to anyone who is interested in seeing them--I figured out how to do that.

rustnrot -- In answer to your question about aluminum chips getting into the motor--the trick I use is very easy to do on the B-series engine. I clamp a fitting in the bottom of the vent hose (the hose on the drivers's side that drips oil on the driveway). I then attach an air pressure regulator with a 0 to 15 lb gauge, attach the air hose to it and adjust it to 1 to 2 lbs MAX. This will charge the inside of the motor with air and, as the drill breaks through the casting, the chips will be blown out past the drill. After you drill the first hole (tap drill) you can increase the flow to clear the chips from the countersink and the tap. This trick also works nicely for finding those oil seeps. I pressure wash the engine, let it dry thoroughly, then hook up this pressure system and watch for where the oil seeps out. If I don't find it, I loosen the oil fill cap, run the engine for a couple of minutes to circulate the oil, shut it off, then try again until I find where the oil is coming from.

MGM -- Yes. As of now we will be crossing PA on I-80.

 

[Joe G.]

I made the part and installed it. Still have to put the rest of the truck back together. My gear housing appears to be the same as the one in the picture on the other thread. The part is shaped kind of like a skinny cam lobe. There is plenty of clearance between the screw head and the gears. The pin protruded about 3/32" so I ground a relief that deep on the back side of the part. I used red loctite and torqued the screw to 18 ftlbs. It's longer than the original. I went down to Dodge and got one the same hardness as the original. This job was done without taking the radiator out. The part is 1 7/16" long by 13/16" at the widest place.

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Joe George
Eureka, CA

'95 2500 CC auto 4X4,3. 54,Combo EGT/boost guage,custom switch panel,PacBrake,TST #5,DTT TC/VB,Automatic motorhome steps on both sides,Foldacover hard bed cover,Cummins chrome kit,Black steel grill guard,Front hitch receiver

[This message has been edited by Joe G. (edited 04-28-2001). ]