Engine/Transmission (1994 - 1998) Gearcase removal questions

[HoleshotHolset]

The old '98 has had an oil leak since I bought it last March. Last summer I swapped out the front crank seal, jigged the KDP with my CPFF kit, and it still leaked oil, but less than it did with the old seal.



Fast forward to late April '05 and I discovered after cleaning the engine that the leak seems like it is between the gearcase and the engine block. It looks like it is focused in the area between the case/block just under the vacuum pump. The oil drips down along the block on the backside of the gearcase and then along the front/side of the gearcase towards the oil pan.



I haven't heard of too many engines leaking in this area = lucky me... I'm one of the few.



Here are the questions for those that have been in situations like this:

1) When removing the gearcase (to repair KDP damage, etc. ) - did you install a new oil pan gasket?

2) What is the part number for the oil pickup tube gasket? I like showing up at the Cummins parts counter with part numbers.

3) Would you install the updated gearcase (that keeps the KDP in place)? (probably overkill, eh?)



I'm installing a new front crank seal with the heavy repair sleeve... is there anything else I should do while I'm in there? I plan on putting locktite on the bolts that retain the gearcase.



Any other comments, suggestions, words of moral support, etc. would be sweet. The truck is all tore down... front cover is off and I'm staring at nothin' but gears - I'm dreading pulling the injection pump and camshaft.



Matt

 

[bmoeller]

Stupid question, I'm sure, but did you check the case bolts behind the cover? I had to tighten mine up, when I was in there to take care of the KDP.



Hope it is that simple.



Is the vacuum pump or power steering pump leaking oil by chance?

 

[HLEschenko]

Are sure it's not the gasket between the vacuum/power steering pumps to gear case housing? I changed that gasket and reduced my oil leakage by more that half. The other part is from the front seal.

 

[HoleshotHolset]

I tried to find some of the case bolts with the cover off last night... I could see two or three total over by the camshaft gear area... and couldn't get a wrench on any of them. This is certainly a job where it would be good to have someone watch over my shoulder who's been there/done that.



The vacuum/PS pump assembly isn't leaking where they usually leak between the two pumps...



As for the seal for the vacuum pump to the gearcase... I'm reasonably sure that it isn't leaking. I plan on swapping that seal out when I pull the gearcase. I want to get in there, change the gasket, and locktite the bejesus out of all the bolts on reassembly... they have a habit of backing off over time.



Matt



On edit: I'm going to go out in the garage and take another shot at the 5 or so magically hidden bolts and see how loose they are. I found a cool diagram that a TDR member posted out of a Cummins repair manual.

 

[Joe G.]

Did you look at this: http://www.flex.net/~triplem/new/dowelpin.htm ?

 

[HoleshotHolset]

Joe: Yeah, I remember that site from a few years ago when Chris Strickland put it together. I printed that up and will use it as a general reminder of the whole process since it is a great reference.



I found all 5 of the bolts under the cam gear... a few of them weren't what I'd consider to be very tight. There's NO way that one bolt is coming out more than 1/2" before it hits the backside of the cam gear.



It looks like someone else has been under the cover of this engine. The crank/cam/pump gears all have nice painted marks on them. Makes you wonder why they were in there before. The engine block looks like it has some of that 'high tack' gasket adhesive on it where the gearcase gasket meets the block. Hrmmm... could the gearcase be warped or otherwise damaged causing a leak? With my luck, anything's possible.



Matt

 

[JGK]

Here are the questions for those that have been in situations like this:

1) When removing the gearcase (to repair KDP damage, etc. ) - did you install a new oil pan gasket?

2) What is the part number for the oil pickup tube gasket? I like showing up at the Cummins parts counter with part numbers.

3) Would you install the updated gearcase (that keeps the KDP in place)? (probably overkill, eh?)

Matt,



To answer your questions (been there, done that - had the same leak and repaired it last spring):

1. No, I did not replace the oil pan gasket. Just put a nice coat of gastket sealer on it when re-installing the gear case.

2. Don't have it, but had no problem getting the right gaskets from Cummins. However, I did not do anything with the oil pickup tube.

3. Wouldn't bother with the cost of a new gear case unless yours is broken. Just tab or retain the KDP with the screw from the side.



Removing the injection pump is not that hard. It's just heavy and awkward. Another set of hands helps. You'll have to remove the lift pump to remove the cam. It can be a booger getting it back in place due to the odd angle of the bolts and the push of the plunger on the cam lobe. Rotating the engine about 1 turn to get on the low side of the cam generally helps.



Yeah, removing the cam is a bit scary. Get the wooden dowls (can't remember the diameter but Piers will tell you) for holding up the lifters, cut a notch in the end if each one and whittle that end to a blunt point. Push them in then pull them up. Pull them up until they pop out to get a feel for how well they're holding up the lifters. They work pretty well when cut and whittled right.



Make sure the marks on the cam gear are aligned with the ones on the crank (I think) before pulling it. When pulling the cam out, it will come out a little way, then get caught. Rotate it a little and go easy. You have to clear the bearing journals (correct name) as it comes out. I will come further, then hang again. Same technique - rotate it. It will come.



Its a big, tedious project just for an oil leak so make sure you've sealed up everything with good gaskets and sealer when you put it back together. Take your time. The scariest is R & R'ing the cam but its not magic.



Might do like I did and spring for a new performance cam while you're at it like I did!



-Jay

 

[vssman]

Matt,



I have a similar leak and haven't bothered to fix it. A 50 lbf bad of speedy dry lasts quite a while :-laf



Paul

 

[SMorneau]

My 96 leaks in the same area. Some of it is coming from the timing pin and some of it is coming from the case to block interface. You might want to try some UV die to find out exactly where it is coming from.

 

[HoleshotHolset]

There's no turning back now.

I have the pump gear off, the vacuum/PS pump and lift pump are hanging in the breeze, etc.



About all I have to do now is pull the rocker arm assemblies off... lift up the tappets and slide the cam out. The fact that the alignment marks on the crank gear/cam gear and pump had paint on them leads me to believe that someone has already been in there for one reason or another. I hope they weren't in there to change the gasket once already...



Besides, what better way is there to spend countless hours and hundreds of dollars (gaskets/seals/o-rings/thermostat/jiggle valve and a new lift pump)? :-laf



I'll keep you all updated. Hopefully this weekend will be productive...



Matt

 

[JGK]

Matt,



After you get the case off and every thing is cleaned up and you're ready to start re-assembly, check the fit of the new case gasket on the block and on the case. It seems to me, due to how the case meets the oil pan and oil pan gasket, we had to trim the case gasket along the bottom of the edge of the case. It's been a year so I don't remember details, but I remember taking a new razor blade to it before assembly. I also used a good, non-hardening gasket sealer on both sides of the gasket before bolting the case on just to make sure it doesn't leak again. So if you choose to do that, just check the fit first so you don't have to trim it with gasket sealer already applied.



-Jay

 

[HoleshotHolset]

Thanks for the tip, Jay.



Would you consider 'Indian Head' a non-hardening gasket sealer? I bought a little bottle of that to hold the gasket to the block during assembly...



Matt

 

[SRadke]

Besides, what better way is there to spend countless hours and hundreds of dollars (gaskets/seals/o-rings/thermostat/jiggle valve and a new lift pump)? :-laf

I replaced a timing case, all the gaskets adn the KDP pin in a 98 after the damage had been done. Saved the cam and gear though. The parts totalled up about $250 so it's not too bad. Just a lot of work to get to it. I also have another buddy with a 98 that has the same leak as you Matt. What do you know... . his name is Matt too



-Scott

 

[KYOUNG]

gearcase removal

cummins puts the paint on after inspection... ... ... .

 

[JGK]

Matt,



If its not too late, the stuff I used is by Permatex and its called "The Right Stuff". Comes in a black pressurized can about 7" tall with a plastic spout.



-Jay

 

[HoleshotHolset]

Jay: Your advice was dead-on about having to trim the gearcase gasket. I would have been :-{} if I had put some gasket sealer on it before test fitting.



The gearcase is back on, cam's in, and I'm setting valvelash. I have to hunt down some threaded rod so that I can press on the crank sleeve... then the gearcase cover can go on.



I've included a closeup shot of the old gearcase gasket. You can see that it was pushed out in one spot and was in sorry shape overall.



Thanks to all for the excellent advice and words of encouragement. The TDR comes through again!



I'm going to wait until I'm done with it before I post all the part numbers and things that caused cuss words. (It'll be a few more days until it's totally done since I'm waiting on hoses and a water pump to come in the mail from RockAuto - I just ordered the parts today. )



Matt

 

[JGK]

Cool! I finally got one right! Glad it worked out for you.



As to the picture, yep, that's about where mine leaked, though mine wasn't quite as bad. Just smashed and pushed out a little.



One thing about this project, once you get through it and (hopefully) all goes well, it greatly boosts your confidence in your ability to do projects like this on your truck.



-Jay

 

[SRadke]

Hmm... guess my mind was out of it that day. Here is the thread with the part numbers from my expereince. Curious if they're the same as yours.



-Scott

 

[JoshPeters]

Geeze Matt..... You should have gave me a jingle! I could have shot down for the weekend or a couple days... whatever! I've only got... . well Way to many tools that would have been nice for the job... . 3 drop lights... etc.



https://www.turbodieselregister.com/user_gallery/displayalbum.php?&userid=16037&albumid=16773



If nothing else I could have helped you drink beer!



Josh

 

[Timgibson]

if it were me id look real close at the oil line fitting where it goes into the injection pump,that fitting was known to weep oil and run down the engine and cause you to swear that it was coming from the front area,lol