roughstock

First of all, for those who havn't tabbed it yet, DO IT. I have 290,000 miles and I thought: Well, if it didnt happen yet, it probably wont. Ill get to it later.

Well, I bought the kit last month and just last weekend, something started leaking and thought it was the front main. Well I just tore it apart today and found a cracked case. The gears are all ok, so i am very lucky. I was driving it until this AM when I started the repair.

I think I will repair it. There is a junk yard that has two 12 valves in it and I can probably get a case for a hundred or less. What is involved in pulling the gears, timing, etc?

Im an idiot. You can say it.

Thanks

infidel

Here you go. CumminsDatabase.com :: 12V Dowel Pin Repair

Remember these aren't complete instructions. If I remember right they fail to tell you about removing the lift pump before pulling the cam.

If you want to make it easier

Most Cummins shops no longer remove the cam when replacing the case, cuts about $600 off the bill. By not removing the cam you don't have to take the front end all apart, remove valve covers or fool around with wooden dowels.

After the timing case cover is off turn the engine till the line up marks on the gears are lined up. A high quality three prong puller (Snap On is best) is used to remove the gear off the cam but there is also a special Cummins puller made just for it that works way better. The gear goes back on by heating it and sliding it on to the cam.

The gear can be heated in two ways, 1) Toaster oven, next to the truck so the gear does not cool down: 2) Propane space heater, one that can have the elements turn up like a grill. Set the temp around 300 F. The oven is the easiest way, depending on the oven it could take 30-45 minutes to heat up, in the meantime you can clean some parts. The propane heater is faster about 10-15 minutes but you need to be fast because the gear will cool down faster and get stuck half way.

You need an extra hand for a few minutes to hold the cam from moving back and pushing out the rear cam plug. The cam is held by removing the fuel lift/transfer pump (don't drop the pump actuator arm into the crankcase!) and using a pry bar on the cam lobe, apply a little force to move the cam toward the front of the engine. The cam can move slightly but all you want is the cam not to move back when the gear is going back on. Once the gear is up to the temp, the crank and cam timing position has been set, someone is holding the cam from sliding back, you then grab the gear with high temp welding gloves and slide the gear back on, sometimes might have to tap it back with a plastic mallet or dead blow hammer but never with a steel hammer. I've done this three times and never had to use a hammer, the gear slid right on.

I would only recommend this to someone with mechanical experience. Sounds a little complicated but is way easier. There are three draw backs: 1) gear cooling down half way, then you have to wait 10 minutes to cool and remove it again to start all over; 2) Not aligning the crank and cam; 3) Allowing the cam to move back and pushing out the rear cam plug, then you will have to pull the engine.

Some people think this method causes a weaker fit for the gear but Cummins has been using this method exclusively for several years, I've never heard of a problem

roughstock

Thanks infidel.

Not sure which method I'll use. I keep telling my self to part it out and get another truck, but Ive got this truck just how i want it and up until last saturday, it didnt leak a drop of any fluid. I was hoping to get another 100,000 to 200,000 out of it.
Ironically the day I find my KDP damage, my brother in Florida just calls and said he just bought a new 08 Ford F250 Diesel Ext Cab. Sounds real nice.

Well, Ill price all the parts on monday.

Are all 5.9 12 valve timing cases the same, (one I can get for cheap is a 5.9 in a ford dump truck) ?

patdaly

So long as they have the P7100 pump they should work.

myojunk

is there no half moon key or dowel pin used at the cam gear and cam? or is it a press fit only with 359 degrees of installing it incorrectly?

infidel

No key.
Gear position on shaft is how timing is adjusted.

roughstock

Is this a good time to adjust the Pump timing?
Is that done by removing the pump gear and moving it a couple of teeth? Or do I still need to remove DV and check for TDC, etc?

infidel

Instructions> http://dodgeram.info/tsb/1994/18-10-94a.htm

To do it correctly involves a couple hundred dollars worth of tools.
For most folks it's cheaper to have someone else do the timing.