4D56 front oil seal

[miked50]

Happened about 4x times on my truck. What could be the cause?
Overspeeding? i don't think so.
no visible "canal" marks on the shaft
no nicks on the housing.
or maybe too much internal blow-by pressure?
This last time i put RTV silicone on the seal's outer lip for additional grip on the housing somehow.
It's too costly also replacing the t-belts everytime the seal jumps out.

[miked50]

oh sorry. what i meant is that the front crank oil seal jumps out very often (4x as stated above).

[Acuta73]

When you seat the seal are you using a bit of oil around the edge? Are you driving it in square and fully seated? Don't install em dry, if you did.

Only things I could think of, unless the seat itself is somehow out of tolerance.

Edit: I don't know a lot about diesels, sad considering I drive a Cummins N14 for a living. I know blow-by is caused by worn rings...?

[miked50]

i always smear oil on the inner and outer lips of seals and use a suitable driver to seat the seals. but in this case only the inner lip is smeared with oil but silicone on the outer.

[camoit]

The case is getting to much pressure in it. Or you may need to put a dimple in the casing after installing the seal. You would use a center punch in 4 places around the seal seat. about 0.010" around the out side. Not on the seal itself. Just the part it sits in. That will distort the aluminum just enough to help hold it in place. Then again you can use some Loctite gasket eliminator 518. It will hold it in there. If not then you have other problems.

[miked50]

thanks for the inputs......

will try that camoit (hopefully not in the near future of course) if ever it happens again....i really hate doing the front assembly. too many parts to take out.

[mikewarme]

You mean the whole seal comes out? What brand seal r u using? Blow by will push oil dip stick out before that. I've never seen that on any of the worn out 4d55s or 56s I've worked on and rebuilt. Case messed up maybe. R you getting it in all the way? Should be flush with oil pump drive gear