More Ford Racing Crate Engine Adventures - Possible Failed Rear Main Seal

[CDXXVII]

Today I noticed oil under the car and decided to take a look. I just hit 5000 miles on the engine.

Here is a link to a pretty bad video but I was hoping you guys could help me figure it out.


https://youtu.be/3utev_lOSAc

It is really tough to tell where the oil is coming from but it is definitely wet at the rear main seal area between the pan and the flexplate. It is also pretty wet where the bellhousing meets the transmission. Everything above the oil pan is dry so it is not coming from the valve cover gaskets or the intake manifold. Would oil make it into the bellhousing if the rear main seal failed? I suspect this would be the case and why I feel it is the rear main as apposed to the pan.

There also seems to be a lot more oil one the clutch fork side. The other side is pretty clean. Almost like oil is coming out of the clutch fork opening.

If it is the rear main seal does anyone have the part numbers? Is it a two piece or a one piece seal?
My engine is the Ford Racing M-6007-Z427FFT

Last Christmas I got to replace my head gaskets. This engine is the gift that kept on giving. Can't say I would recommend one to a friend.

[scottiec]

It should be a one piece the older motors from ford were two piece. Someone correct me if I’m wrong

[boat737]

Hard to tell on your video, but is there oil/wetness on the FRONT surface of the backing plate? (the plate on the forward side of the bell housing?)

[CDXXVII]

Yes, there is oil on the front of the backing plate on the engine side.

[Riflebolt]

If you haven’t already, you might check valve cover gaskets. Not saying that’s it, but definitely an easier fix than a rear main replacement. Had the same problem you are seeing and turned out the oil was running down the sides of the engine to the area you are showing. I found the culprit by using dye in the oil.

[boat737]

I also had a slight oil leak that had a drop or two on the bottom of the bell housing. It took a week of looking around the motor, but found a "seepage" from the driver's side valve cover. It's minor, and still there, but I wipe the area after every few drives. On my list of post build fixes, changes, and adjustments, I need to pull that valve cover and see if I can stop the leak. So far it's minor and not that big of deal, but I do need to address it at some point. Maybe this week...

As stated above, double check that (or both) valve cover gasket(s). The oil on the front side of the backing plate may be the clue.

[Gordon Levy]

It has a 1 piece rear main. Looking at it I think you have 2 leaks, one is the rear main and the other is the pan.

[CDXXVII]

Would this be the correct rear main seal?

Ford Performance Parts Rear Main Seals M-6701-B351


I already have an extra "New" Ford Performance Pan and Gasket. Long Story!!!

Ford Performance Parts Oil Pans M-6675-FT351
Ford Performance Parts Oil Pan Gaskets M-6710-A351




It has a 1 piece rear main. Looking at it I think you have 2 leaks, one is the rear main and the other is the pan.

[steno]

One possibility is the rear main bearing cap doesn’t have any sealer on the surface where it meets the block. That’s where I found mine when I replaced a seal twice!

[TNcoupe]

What happened to make you replace the head gaskets?

I have the 427 FRPP crate engine in a 64 Fairlane and I cant seem to get it anywhere close to tuned correctly. Have had nothing but problems out of it since I installed it.

[bingo2]

Marcel,

Before you begin tearing it apart, clean up the mess and get a dye kit. You'll be better able to identify the location of the leak. If it is the rear main, look at the Mr. Gasket site, they sell a sleeve kit with an installation tool and there are two different rear main seals; one that is installed wet and another that is installed dry.

Also, if you don't already have one, get a tail plug for your transmission, it will minimize the fluid loss. I have a low profile transmission jack that you are welcome to borrow.