Engine/Transmission (1994 - 1998) KDP , using jig ?

[JFaughn]

I am getting ready to use the jig , with others at a wrench day [ Minnesota ] , and I am not sure , when drilling & tapping , is this all with in the cast cover , as apposed to allowing chips inside the cover , something like drilling & tapping for exhaust temp probe for turbo ?
I am not a fan of putting chips into moving parts .
Thanks John

 

[SEmerson]

put greese on the drill and tap. That will catch most of the chips.

 

[Steve St.Laurent]

When I did it we used an air compressor to blow air through the block so that it was blowing any chips out the hole as we were drilling and tapping. The instructions tell you to do so and it worked great. Just don't run it high enough to push out any seals - you want just enough to blow the chips out.

 

[Bob V]

It is just as easy to do the tab, and you will know that you got it!

 

[JFaughn]

I have an issue with any tricks to lessen the chips , chips are not good weather there are a lot or a few .
I haven't used a jig yet so I was hoping to hear that the drill & tap were contained in the cover [ no hole exposed into the eng. / oil ] .
Tabing involves taking the cover off [ and all the it takes to get off ] not just as easy , but since I haven't done it yet , thats the way it appears .
Just one more try at having my cake & eating is too .

 

[Joseph Donnelly]

Up to about 1996, there was no sealer/loctite on the bolts inside the case. They can also come loose and their flanged heads can go between teeth of the gears, locking up the engine, breaking the cam or block. I recommend removing, cleaning, loctiting the bolts. Two are reached through windows in the cam gear, one can't be removed but can be tightened through a window with a bent 10 mm open end wrench.

 

[Woodenhead]

When I did the jig fix many (5?) years ago there was a small regulator in the kit that could fit over the dip stick tube. I believe it was set at 10psi and I can't remember if the blowby tube was plugged as well. When the drill made its way through the case the shavings were being blown back out. Not sure if any made it in.



There have been many trucks jigged and I can't ever recall reading about someone who's run into problems with chips in the motor. Worst case is a small chip rides around with the gears and ends up in the pan. All the oil goes through the screen in the pickup tube then through the filter before going anywhere where it'll hurt anything anyway.



I just took a hole saw to my oil pan to make a drain line for my twins and I'm sure some chips made it in but if the magnet doesn't get it the filter will. No worries here. I do still need to find the slug that fell into the pan from the hole saw .



Yes doing the tab fix is the best method but if you have the jig handy and don't have the tab kit or the means then there's nothing wrong with the jig fix. I just tabbed mine recently because I needed to do a front main and the dowel was tight but the jigged screw was in front of it just like it should be.



Remember if you can't get the 1" screw threaded all the way in then it's likely hitting a dowel that's started to come out. Then you need to install the 3/4" long screw to plug the hole and do the tab fix ASAP.



That's my long winded $0. 02.

Mike

 

[JFaughn]

Does some body have the size pitch ect for the bolts , I've got the jig coming for a wrench day were having in MN. Sept. 1 , and I should pick up a few bolts for those that are going to do this .
Thanks John

 

[JFaughn]

Still looking for size of bolt .
Thanks John

 

[Woodenhead]

I did a quick search and it's a 1/4 - 20 socket head counter sunk machine screw. As mentioned about you'll need 1" long but maybe 3/4" if the dowel started to come out.

 

[JFaughn]

Apparently I have to use more space to say thanks .

 

[GTaylor1]

The style of tap used can also be helpful. The best choice of tap style for the application would be a spiral fluted tap. The geometry of the flutes on this style of tap is designed to extract chips.



A straight flute tap is OK if you are careful, but do not use a spiral point or gun style tap if you are concerned about chips entering the cover. Spiral point or gun taps are designed to push chips forward in through hole applications.

 

[JFaughn]

Thanks again .

 

[tp0d]

Screws to hold the KDP are included with the kit. A short screw is also included, in the case that the KDP is out too far for the jig to work.

-j

 

[Bob V]

Here is a copy of a post I did a few years ago. It is possible to knock the pin out if it is part way out when you drill the hole.



Last weekend I did the dowel pin and timing on two different trucks, one '96 and one '97. I have been involved in 15+ KDP jig fixes and wanted to try the tab method, and I knew that setting the timing would be easer with the front cover off. It took us about 45 minutes to get booth front covers off. The '96 looked good, pin was tight, but the bolt beside it didn't have much torque on it when we removed it to install the tab.

The '97 wasn't so good. When we pulled off the cover we heard something drop. The pin had fallen out and was wedged between the front cover and the cam gear, the pin was ground down about 1/3 its diameter. Other that some denting to the front cover there was no permanent damage. In this case a jig fixed would not have done any good. I don't know what would have happened if the pin was left in there and eventually fallen through. The gaskets where both in good shape and well sealed to the cover. I think that some good quality silicone would have sealed up fine with the old gasket.

After doing both methods for preventing KDP failure I would recommend the tab method. I don't think that it is that much more work and you know that the pin and the bolts will be right. Here is the Cummins part # we used.

Seal 3804899 ($28. 80)

Gasket 3918673 ($23. 05)

Tab 3958017 ($1. 00)

Bob V

 

[JFaughn]

I wanted to tab mine , that would also give me the chance to do the crank seal also .
But I'm getting set up for a wrench day in MN , Sept 1 , so I figured I would get a few of the bolts .
Thanks