Engine/Transmission (1994 - 1998) Engine oil leak in my 1998 12 valve

[HerbW]

Hi.
I noticed for the first time ever an oil spot on my floor under the engine other than the oil out the breather pipe. I can't tell where it's coming from yet but I think it may be the front crank seal or the KDP. I've never did the KDP fix even though I've got the parts to fix it if I take the cover off. Oil seem to be everywhere on the front underside of my engine. Not a bad leak but still there. Can the front seal be changed out without pan removal? I haven't looked it up in my manual yet. I'm hoping to do the seal and KDP in one swoop. Oil leaks that are even minor are hard to live with for me and my concrete floor. LOL

Any ideas are appreciated! Thanks TDR buddies! Herb

 

[Woodenhead]

Is it dripping or running out? Why not just take a few hours and pull the front cover, kill the KDP and install a new front main? You'll be kicking yourself for a long time if you have to fix the carnage if that pin falls out.
It's tight at the front of the motor, it'll be difficult if not impossible to change the front seal without pulling the cover unless you tear the front off the truck. Plus the risk of damaging the seal or the end of the crank wouldn't be worth it.

Another source for leaks near the front is the vacuum pump but that'll be off to the drivers side a bit.

 

[HerbW]

Tomorrow is the day to fix, I hope!

Woodenhead, I have oil one both sides of my engine. It's on the bottom of the vacuum pump and up a ways like a camshaft cover leak and is also on the botton of the AC pump on the other side of the engine. It looks freshest behind the damper pulley as I recently did an oil change. I wonder if fan wind could blow if up both sides like this? The oil then runs back to the rear and drips off the oil pan.

If the vacuum pump is a leak, does the timing cover need removed to remove it? Thanks, Herb

Is it dripping or running out? Why not just take a few hours and pull the front cover, kill the KDP and install a new front main? You'll be kicking yourself for a long time if you have to fix the carnage if that pin falls out.
It's tight at the front of the motor, it'll be difficult if not impossible to change the front seal without pulling the cover unless you tear the front off the truck. Plus the risk of damaging the seal or the end of the crank wouldn't be worth it.

Another source for leaks near the front is the vacuum pump but that'll be off to the drivers side a bit.

 

[hsmith]

#1 No. The oil pan does not need to be pulled.
#2 Do not attempt replacing the seal without pulling the front cover.
#3 Vacuum pump removal is done from the rear of the timing gear housing.
While you are in there with the front cover off tighten the 10 mm bolts securing the cover to the block. You will need to rotate the engine for access through slots in the cam gear.

 

[HerbW]

Back to work on my Dodge!

#1 No. The oil pan does not need to be pulled.
#2 Do not attempt replacing the seal without pulling the front cover.
#3 Vacuum pump removal is done from the rear of the timing gear housing.
While you are in there with the front cover off tighten the 10 mm bolts securing the cover to the block. You will need to rotate the engine for access through slots in the cam gear.

This is why TDR is worth yearly fees!
My friends here are full of experience. Much more help than getting the manual out and trying to make sense of it!
The power is off and we are in a bad wind storm so it may wait till next week to terrorize the front of my engine.
My plan is to pull the timing cover, replace the front seal, tab the KDP, drain the antifreeze, remove top and bottom water hoses to radiator, replace the water pump/refill with new antifreeze and wash out my radiator while out of the truck. Oh, I think I'll replace the hoses to radiator. No cooling issues but they are fifteen years old! Then save these to take on long hunting trips for spares.
I just might go replace my front disk brakes today. They are grabbing and acting "funny". I can do them without aux lighting as they are frequent wear-outers! Thanks to me for building a pole barn and putting in a concrete floor!

Thank you all for the help. Herb

 

[EWalshak]

If you say it looks fresh right behind the dampner. It most likely is the front seal leaking and the fan blowing it back over the motor. I agree with hsmith, the bolts that hold the front timing cover on are just as important to address when you get the timing cover off. I did the KDP on both my motors and the cover bolts were mostly all loose on each when I did the fix. The best thing to do is remove them one at a time, blow the holes out, squirt a little carb cleaner or brake cleaner in the hole, blow it out again, insert bolt with locktite and torque to correct in/lbs. It will be worth the time it takes. There should be 5 bolts that hod the cover to the motor. If I remember right the two behind the cam gear are the trickiest to get to.I also did my oil pump bolts as well. It sound like you got a nice truck. 12v quadcab is on the rare side. I love mine. Keep us posted.

 

[RPosey]

Per directions supplied with cummins front crank shaft oil seal, DO NOT OIL THE SEAL.

 

[HerbW]

Nice info guys! Thanks!

Per directions supplied with cummins front crank shaft oil seal, DO NOT OIL THE SEAL.

Well we had a major wind storm last Saturday and Sunday that left me without power. Need good lighting to do a great job. Next weekend is my target date to do the front cover. I plan on using gasket maker silicone without a gasket on the cover. That's what the TST install guide recommends from TDR. What do you think?

I'll then probably install a new water pump, hoses and new antifreeze while the belts are off.

 

[Woodenhead]

You have a good plan, replacing what you can while you're in there. It's cheap insurance. Yes, use silicone not a gasket.
I like the GatorGrip belts.

 

[HerbW]

My killer Dowell Pin!

Here is a picture of my KDP before fixing! I'm having troubles loading the pictures. Herb

 

[Woodenhead]

Looks fine. Tab it, loctite and torque the cover bolts and your good to go. How does the front crank seal journal look? Sometimes they get a good groove going and need a sleeve.

Looks like you and I have similar rigs (98) except mines a handshaker and way more miles.

 

[HerbW]

The work is done on my KDP!

Looks fine. Tab it, loctite and torque the cover bolts and your good to go. How does the front crank seal journal look? Sometimes they get a good groove going and need a sleeve.

Looks like you and I have similar rigs (98) except mines a handshaker and way more miles.

Well I did it all last weekend!
The case and cover bolts were loose. The five that holds the gearcase were only about half their torque. I put RED Loctite on them and torqued them at 18 ft. lbs. The KDP I punched inward and tabbed it. I used only orange gasket maker silicone for the cover(no gasket) and installed a new crankshaft gasket. The darn silicone took forever to gel up some due to cold weather. My crankshaft wasn't scarred at all, just more polished looking where the seal touched.

While apart, I put in a new water pump, top and bottom hoses, antifreeze and washed out the radiator. All the old stuff looked great but they are 16 years old! I had trouble with the large squeeze type hose clamp that fits on the lower hose and engine. Ended up buying hose pliers to get it on. I like them better than hose clamps. I even sanded the camshaft cover and painted it RED!

Now tonight I see an oil drip. CRAP! Could be run off from being apart. I'm going to pressure wash it all tomorrow. Looks to me like under the AC unit. Seemed like here before. The old crank seal didn't look like it leaked. Is there anything near the AC pump to leak? The oil filter is clean.