KDP Question

[gitchesum]

I'm planning on getting mine done in the near future so here's my question. Instead of the KBP tab, why can't you just hit the edges of the timing case gently with a chisel and bend a little of the timing cover hole over the dowel pin?

This should keep the pin where it belongs.



Anyone have something against that?



Not knocking the tab or the CPFF jig, just a question.

 

[illflem]

Curtis, it would be sort of hard to do because the pin is flush with the cover when it's all the way in.

 

[grtescpa]

KDP

I plan to check mine real soon. If its on its way out, I am going to try to use a slide hammer puller to remove the pin. Then grind about a 1/8 off and retap it back into the housing. Then use the center punch method to the side of the dowl pin hole. This should

stake the pin in place. Has anyone thought of this ???

 

[gitchesum]

Hell, if all the KDP is for is for lining the timing case up on assembly, why not just take it out and leave it out? Won't the bolts hold the timing case in place?

 

[Dieselnerd]

It's true the KDP could be left out, if you could get it out. I remember from some old posts last year that the pin is very hard to remove. It's also made of hard metal that is not easily drilled for using an EZ out. If it's almost out it could probably be pulled out with a pliers and then left out.

 

[illflem]

Removing the pin is definitely not an option.

The pin is there for more than just assembly, it keeps the gears lined up. Without the pin all that holds the case in place is the bolts, which have slop. The results of running without the dowel pin include but are not limited to fried injection pump and main shaft bearings and seals.



grtescpa, without taking your entire front end apart, radiator,intercooler, etc what you speak of is impossible.

 

[Clinton]

I did mine and a friend's with the Southeast jig a couple of weeks ago and I have to say I can't imagine going any other route. That jig and all that came with it made that task so easy. Less than an hour per truck and an easy hour at that. I wondered about other solutions too, but after using the jig let me encourage you to get on your local waiting list. Here's to you CPFF, wherever you are.

 

[Matt42]

KDP Musings, FWIW

When I covered the KDP on mine, the pin was recessed about 1/16" to 1/8" below the surface of the gear case cover. Theoretically, I could have peened the cover's metal around the top of the pin to resist outward motion. It's doubtful that I could have peened enough of the aluminum around the hole into the recess to make a difference. Then again, I might have just succeeded in causing the aluminum to break or chip, not flow.



The pin is hard steel. Over time, the steel pin would probably push the peened aluminum back and fall out anyway. It just might have taken longer.



I'd (safely) speculate that the KDP is a problem only in engines where the KDP hole in the cast iron block is slightly large, but within spec, and where the pin is slightly small, but also within spec.



I suspect that there may be some correlation between heat-cool cycles that contributes to the pin falling out, all else being equal. The steel pin and cast iron block will expand at different rates when they warm up. I'd speculate that engines that are started (warmed up) and stopped (cooled) frequently (like mine) may be more likely to have the problem. (Observations?)



This reminds me of a defect in the mid-1970s Volkswagen Type II engines. There, three steel pins were pressed into the magnesium-aluminum alloy block to seal off the oil pressure gallery after machnining. At 74K to 85K miles, one press-pin would fall out, causing massive engine failure. (The pin that fell out did not cause the oil pressure idiot light to immediately illuminate, assuring max shredding. ) Engines used in frequent heat-cool cycles, like a daily commute, failed sooner. In the VW case, the quick fix, on rebuild, was to replace the press pin with a threaded pin. The true repair was to replace all three. But I digress.

 

['956Wheel]

Ideally peening the hole would be the best fix, however as Illflem points out, the pin is flush with the gear cover and you would have to shorten the pin. I did the tab fix and used Loctite 242 (blue) on the bolt holding the tab.



If one wanted to do other types of fixes, they are numerous, ie,



1. Drill and tap a hole, 8-32 or so, allowing the head of the bolt to block the pin, Loctite the bolt in.



2. Drill the end of the pin and tap it, pull it, shorten it, replace it and peen over the hole.



3. The pin hole is 5/16 (tap drill for 3/8-16 NC) pull the pin, tap the CASE, turn a new pin with 3/8-16 threads on one end and pin size on the other, screw it in with Loctite.



The pin is NOT just for assembly, it is also to precisely locate the case, something that bolts can't do.



The 2 fixes are fine and its a matter of choice... I did the tab as the front main was seeping a tad ... 2 birds, one seal!



Oh, yes Loctite is my best friend with the vibration of this Cummins!



Mike

 

[QRTRHRS]

Originally posted by illflem

Curtis, it would be sort of hard to do because the pin is flush with the cover when it's all the way in.

Not on mine. I found my pin to be floating in the hole. I grabbed it with my fingers and could slide it back and forth but not pull it out. Did not try with pliers though. Anyway, mine would not go flush rather it sticks out maybe 1/16" to 1/8". If memory serves, I think I read of others doing this.

 

[SlyBones]

Either method, if you own a 12v get this done. Was up visiting Piers yesterday, and in the shop was another victim of the KDP.

 

[Bill Lins]

Gitch- I had intended to do the jig fix earlier this year while Andy Redmond was in Houston, but I got tied up and couldn't get with him. If you want to see if we can get a number of trucks lined up, I'll call him and see if he'd be willing to come back down to do them.

 

[gitchesum]

I've gotta pull the cover off to fix a leak so I'm gonna tackle it then. I'll just manufacture the tab to do it with.

Probably get it timed then as well.

There might be others that want this done though. I'll help as much as I can.

 

[Blakers]

Can someone please give us a refresher in how the KDP jig works and what's involved with the repair? I know this has been discussed before, but a refresher would be nice.



Thanks,



Blake

 

[gitchesum]

Blakers,

Shoot me an e-mail and I'll send you the pics. I'm out of room on my server to post them on the web.

-- email address removed --

 

[moparguy]

gitchesum, I made a really great tab to cover my KDP. It was a piece of art and I was ready to use it. When I pulled the cover, my pin was almost flush, it may have been out a 1/32, using a mirror and a short brass hammer and short punch I drove it in into the housing about 1/8th".



Now I'm thinking, I can peen this sucker or tab it. The Cummins fix is to clean and degrease everything and use green penetrating Locktite to keep the pin in place.



So, after much delibration I used the green Locktite and peened it in place. The aluminum is easy to drift into place, works great. I made several large dimples with a sharp, short punch just outside the edge of the hole. Drifted lots of metal in place to capture the pin, then cleaned things a second time and Locktited it in place.



My logic was why add another piece of hardware that might in the next hundred years cause a problem.



LarryB did the same and peened his KDP.



In closing this little novel, I don't think my KDP would have ever been a problem. I am glad I did the fix, and used Locktite on all the other bolts under the cover.



Ronnie