Kdp & Cdp?

[KRoaden]

Hey guys I hate to sound new but, I am. What is KDP & CDP. I know some of the gasser term front main seal etc. Help a guy out OK. Thanks!!!!

 

[M Barnett]

As you're running a 96 you need to study up on the KDP which is killer dowel pin. Do a search and read up on it. I really wish somebody would do up a glossery for the newbies as there is so much abbrevation on this site, it takes a while to understand what is being talked about.

M Barnett

 

[rrausch]

Ditto that M. Barnett. The pin (KDP) is an indexing pin used to define exactly where the front cast-aluminum gear cover sits on the block. The pin is pressed halfway into the block and then when the cover is installed, it goes on at exactly the right place. Pretty neat. But in the 12V's, especially 97's but in other years also, that darn little pin can work its way out of it's little hole and when it does... PAIN & $$$$! Because the pin falls down into the meshing gears and gets rammed through the cover or worse, resulting in a LOT of NASTY DAMAGE!

So a TDR member named CPFF machined a set of ingenious jigs, to install a small bolt to block that pin from falling down into the meshing gears. Hence the posts that say things like "I Killed my dowel pin last weekend... "



So these jigs are circulating all over the country, now, thanks to CPFF.

If you kill your Dowel Pin, send CPFF a twenty to thank him!

 

[Hookemupman]

Whats involved in fixing the killer dowel pin before it movesand causes damage,about how much time does it take to do,ive got a 98 12 valve. How do you go about getting the jig?Thanks Jason

 

[M Barnett]

Jason, you need the fix. I am keeping track of one of the jigs and its on the way to Inverness, Fla. , as we speak. How far are you from there? It would sure be nice if you could go there and do the fix with them. There will be several fellows doing theirs. I will send you his e-mail address and hopefully you can get together.

M Barnett

 

[SlyBones]

The other popular fix for the KDP besides the jig method, is the tab method. You remove the timing gear cover, install a washer that will hold the pin in place, and then reinstall.



The tab is more work, and requires more tools, gaskets, mechanical skills, etc. However its less risk. The jig is much less work, less skill set, etc. However some worry about the metal shavings from drilling and tapping. Some dont think its a big deal.



Either way everyone with a 12v should have this done. You only need to determine the amount of effort, tools, skills versus your own risk assessment. On here people will argue which is better for a long time. Decide for you and get it done.

 

['956Wheel]

DO IT RIGHT

Do some searches on the fixing of the pin. Being you have some miles on yours, chances are you have some seepage from the front main seal. If you "tab" the pin the most difficult part is fan removal. The fix with the jig is a shortcut, IMO, and is faster but you do not have the advantage of seeing if the pin moved as well as seal replacement. Some members may "fire off" in my direction and thats o. k. . this is due to the "jig fix" being so popular. It will be interesting to see the feedback on my stubborn opinion!



Mike

 

[Hookemupman]

MBarnett,i live agout 80 miles south of Inverness,I did not get the email address,for the guys that are doing there trucks thanks for the info

 

[Jim Fulmer]

Just an opinion

Just a thought from me, I did the tab method last fri on mine and I thought it was way over rated for being hard, yes there are hard parts to it... . Removing the fan and installing the front seal but other than that it was too easy. I wish more of you guys were close to OKC Ok then I would show you, one thing is I built a tab out of 10 guage instead of using a washer. If you want all the directions E-mail me and I'll give them to you, I don't have a problem with spreading good info!



Jim

 

[SlyBones]

I guess I dont see the jig as a shortcut. Once installed either one of them hold the pin in place and prevent the pin from coming out, equally as well. The final solution works just as good in either case. To me either one is fixing it right.



I dont see why you need to see how far the pin has moved. If you can get the drill bit to go in to the proper depth, and you can get the set screw in place, then the pin has not moved or has moved so little, that worring because you cannot see it is pointless. -- Now if you cannot get the drill bit in, and the set screw will not go in, now you know you are in trouble. You CAN tell the pin has moved. You CAN tell the pin has moved to a point that is suitable to start freaking out. You install the "short" set screw to cover the hole you drilled and tapped. Now you are have to remove the cover and fix it that way.



Given that, the Tab method does have the advantage that once you get into it, it can be fixed in any case. With the jig, if its moved too far, and you are not prepared with seals and gaskets, etc. you will have to come back another day. A very soon other day.



There are a few other opinions, that I think are more convenience depending on your particular situation, not things that make one better that the other in terms of solution. -- It really boils down to the metal shavings thing and whether you feel that is a problem or not. IMO.

 

[Deezul1]

Did the tab fix today and it isnt hard at all. Takes about 3 hours and on the 2 we did today the bolt next to the dowel pin was just barely tight which seems common. All the other bolts were tight. The fan removal is pretty easy, I usea air hammer with a blunt chisel in it and give it a shot on the edge of thebig nut to spin it loose. A chisel and hammer would work too as it doesnt take much to kick it loose and then it spins of and will come out the bottom, remember that nut is left hand thread.

 

[Joe G.]

As far as seeing what is happening is concerned, one member had his KDP fall out with he put his long nose pliers on it. If he had been using a jig it would have fallen out and he would have found out about that the next time he started the engine. I realize that is kind of a rare thing, but entirely possible since you can't see what you are doing with the jig. I've very uncomfortable with that kind of thing.



The other thing about the tab fix is that you can do it anytime you want. NO getting on a list. NO waiting. NO packaging and shipping.

 

['956Wheel]

Sly, You are right on the "come back another day". Why play any guesswork whatsoever when the option eliminates any and will allow a more through and clean fix.



Now, drills feed chips out and taps push them in so when does the vacuum come into play?? Remember the post on slipped timing being stopped with chaulk on the tapered P7100 shaft? One reply was tremendously concerned about chaulk dust in the oil... now the possibility of steel and/or aluminum chips does not seem to matter? Humm? IMO more selective debates.



At work we will split the case on a 750 megawatt turb/gen to check things out, the upper H. P. case weighs in at 70+ tons... and thats the small one! Pointless?



IMO Do it right or do not do it at all! Now, mark my word on this one: Some day you will see a post on a broken timing case after the "jig fix"... why? Cause it is precision guesswork.



Mike

 

[Jim Fulmer]

Deezul1... Good to hear you have it fixed now, Thought you would think it was easy. Joe George, thank for the E-mail instructions and pics on the tab method, worked out great!



Jim

 

[M Barnett]

Now, drills feed chips out and taps push them in so when does the vacuum come into play?? Remember the post on slipped timing being stopped with chaulk on the tapered P7100 shaft? One reply was tremendously concerned about chaulk dust in the oil... now the possibility of steel and/or aluminum chips does not seem to matter? Humm? IMO more selective debates.

I don't understand what you mean by vacuum? I assume chalk dust is abrasive, I don't think aluminum is. There are no steel chips involved. I think there is a lot of misunderstanding what is going on in the procedure.

M Barnett

 

['956Wheel]

HUH

M Barnett, Many are using a vacuum connected to the oil filler to "assure" no chips are left in the gear housing. Concern over the possible abrasive nature of chaulk... . if it is the filter will get it, however a chip can clog an oil gallery or piston cooling nozzle. It is VERY common practice to use chaulk on a tapered shaft to stop slippage. I have been a Machinist for 25+ years and to worry about chaulk dust is a moot point.



What we can see here are simply differing opinions, some with fact others with pride blocking fact... take mine as you wish.



Mike

 

[illflem]

Mike, when the jig is used per the instructions you use compressed air not vacuum. When done right the drill and tap chips shoot out almost a foot from the hole while drilling and tapping.