Guess What Guys, I found where my 2qt/1000mi leak was coming from! Too bad I think the CRACK IN THE GEARCASE has something to do with it!

Now the question is, What are my options as far as fixing it goes? Do I need a new gearcase, or can I fix the old one so it will hold, not just a bubblegum job to hold it 'till I find a buyer, I like this truck.

Please let me know what I can do, any help is greatly appreciated!!

Thanks in Advance Guys,
Chris

BTW, would this have anything to do with my timing problem, like why it slipped 3 months after it was timed? Not like it matters much now

 

Until you open it up and look inside as to what is dammaged there is really no way of knowing what is to be done, some have had luck if the crack is not down in the gear case to far by simply patching it, I would suggest to open it up and see what is the extent of the dammage, sorry to hear your delima, let us know. Goodluck,,Rick

 

Anyone know if ALL 6B5.9's used the same gearcase?

The reason I ask is that some tractors we sold had that engine in lower power levels, 95-145hp, and I can prbably get a new case for cheaper than Cummins.

Let me know the technical side of it, like what else could be broke. I want to have an idea of what to look for if I do tear it down.

Thanks Again,
Chris

 

No there are different cases.

 

Thanks Haulin,

I forgot that i could look up Cummins parts, so I got my Engine Serial Number, and fired up the computer.

New Gearcase, pt #3936256, $214.12. Not as bad as I thought.

Anything else I should think about.

Thanks,
Chris

 

the new case will have a stepped hole so that the KDP can't back out again, so that's covered...

I would use gray silicone to seal the case to the block... if that gasket ever leaks on ya, it's a pain to re-seal. clean all the bolts and bolt holes in the block w/ brake cleaner and use some medium locktite on 'em when you torque 'em down. Those timing case bolts have caused lots of damage... not as often as the KDP, but that bolt right by the KDP will back out and fall down into the timing gears, and OUCH!!!!

oh yeah, if you plan on makin' some more power in the future, I'd go ahead and call Piers and have him send you a camshaft since you're already gonna be pulling yours

Forrest

 

Well I got the new case, and if the old one's cracked, so is the new one . The new one has the same "cracks" in the same spot as the old one, so the "crack" turns out to be a rough casting.

So, I think it's back to being a front main seal. I think I'll still tear into and fix or check the KDP while I'm in the mood, and while I've got help. Thanks so far for all of your help, you guys are great.

I'll let you know what I find out.
BTW, Would it be better to pull the radiator, intercooler, and such so that I can get in there, or just take out the fan and stand on my head?


and Forrest, I'd love a new cam, but I don't have the money right now. I think I'll wait until I pull the head to have it o-ring and then do the cam.
In the meantime, anyone know if a 24v head will go onto a 12v block, or would it be easier to find a 24v to P-pump?

Chris

 

I'd go ahead and tab the KDP, loctite all the timing case bolts, and put a new front seal in. there's a good chance you're leaking between the case and the block, but there's also a good chance that re-torquing the bolts will help seal it up better. you CAN unbolt the case and just squish a bunch of grey silicone behind it to help seal it up.

I hear ya on not having the money... I'm really good at spending other peoples money, but I never seem to have enough to do the cool stuff to MY truck!

I wouldn't mess with the 24 head swap... it flows a bit better, but the highest powered trucks out there run 12v heads. I think the angle of the injector limits power production... lowering compression causes spray pattern alignment issues... advancing timing causes spray pattern alignment issues... and never mind the cost involved.

Just go with a well ported 12v head and a cam, and you're in business.

Forrest