leaking front crank seal

[mmarriott]

I have a 99 ranger 4.0 with a leaking front seal. I replaced the engine a month ago with a remanufactured. Put in a new seal at the time and found it to be leaking soon after. just replaced it with another seal now its leaking even more. As I recall there was not lip on the inside of the timing cover for the seal to sit. I think the seal is not staying straight as I place the crank pully. Any body know exactly where the seal should set in the cover and any other thoughts out there would be appreciated before I do it for a third time.

 

[RonD]

There are some good pictures here: http://www.explorerforum.com/forums/showthread.php?t=307250&page=2

Post #33

Of what you should see when reinstalling seal

Interesting method used in this post, heating up the pulley assembly in the oven and then installing.
"So far, the best tip I've gathered from the forum search feature is to heat the crank pulley/harmonic balancer assembly in a oven at 250 degrees Fahrenheit for 30 minutes."

Also check the pulley shaft that the seal rides on, it may have a burr that is slicing up the seal.

 

[drsvox]

To add: though I've never used them, I hear the Redi or TimKin repair sleeves do a really nice job of helping mitigate crank and rear main leaks. From what I've priced, kits are fairly inexpensive and come with an install tool which can also be used to tap in the new seal.

 

[mmarriott]

Great info, as i was checking for other possible leaks I noticed oil in the throttle body entry, which I think is coming in through the tube off the oil filler tube? Should that be spitting out oil?

 

[RonD]

That is the Vent Hose.

It is part of the PCV(positive crankcase ventilation) system.

Your PCV valve or PCV valve hose may be clogged up or cracked if there is oil residue in the Vent hose.

Normal PCV operation has the PCV valve/hose sucking air out of the valve cover/crankcase, via the vacuum in the intake while engine is running, the vent hose allows that air to be replaced, so flow in the vent hose should be > to the oil filler tube, not > to the air cleaner.

Check the PCV valve and hose first, 99.9% of the time that will be the issue.

All piston engines(even brand new) have "blow-by", when a cylinder fires some of that expanding gas will "blow-by" the piston's rings, this does two things, it increases pressure in the crankcase and it vaporizes some of the oil on the cylinder walls, this is where the engine oil vapor comes from, oil squirting out of bearings and valve train is more of a "mist" than a vapor so will settle out pretty fast.

If you don't change oil as recommended or use a cheap oil you will get more oil vapor than "normal".
Blow-by increases with RPM(cylinders are firing faster), and as RPMs go up Vacuum in intake goes down, so at a certain RPM(and engine load) there will be a break even point, where vacuum is lower and blow-by is higher, above this point the flow in the Vent Hose can reverse and oil vapor will travel into air filter and into the upper front of the intake.
This can be "normal" under high load and high RPMs, but it would be short duration, so shouldn't show any signs in the intake, unless oil is old and there is alot of oil vapor.

As rings wear down(high miles) blow-by will increase and the break even point will be lower.
Ring condition can be tested with Vacuum gauge or dry then wet compression test.

A general vacuum leak will lower vacuum over all so break even point is lowered.

 

[mmarriott]

Thanks for the info, I just replaced the PCV but will give the hose a close look.

 

[mmarriott]

I have replaced the front crank seal 3 times and still can not keep it from leaking. And it leaks really bad. I believe that it is the seal leaking because there is oil, drips, on the underside of the water pump but no signs of oil above that point. And of course lots of oil below that point and spread out all the way to the front fender well on the driver side. With lots of oil on the power steering fluid cooling fins below the front of the engine etc.
I replaced the harmonic balancer instead of using a repair sleeve because I have not been able to determine where the seal should set in the timing cover and the sleeve does not extend the full length of the balancer shaft. Another thing that seems to happen is as I place the balancer on the crank it seems to be pushing the seal in instead of slipping through it. I’ve oilded both the inside of the seal and the balancer shaft. This last time I set the seal in about three eights of an inch, and noticed that as the balancer went on the seal moved back.
So I’ve been thinking next time I will leave the seal flush with timing cover and let the plastic ring around the balancer seat the seal. I don’t like the idea of the plastic ring rubbing on the seal, but just don’t know what else to do? Does anybody know what that plastic ring is for or just how to do this?