Now that I have finished bragging about how fantastic my F250 is .... it is leaking oil out of the rear main seal . Fully rebuilt '67 Mustang GTA 390 , but it did sit for a couple of years before the truck was finished. Maybe the seal dried out over that time, I don't know what could have happened.
Now... do I have to pull the whole damn thing out to change the rear main oil seal, or should it be a simple pull the pan, and replace... Thanks for your assistance. Peter

 

Peter, The FE series is not big on rear main leaking, but is well versed in rear intake, and valve cover leaking. Get a light and mirror and check above the bell for oil, clean the area and get it good and dry before firing it up again.

The FE seal is very different from others and you really don't want to try to replace it in the truck.


John

 

Did someone try to use a rope seal? Not sure they're even available?

It will be quite a job in the truck, so likely better to pull it(though a bit of work). Like John mentioned, get under there and confirm it. I had a real oil galley plug leak(seemed like oil pan or rear main), as it seeped around the center. Seems the pipe plug wasn't tapered enough and it just weeped constantly. I finally pulled the tranny(stick) and was able to pressurize the system using a drill and rod thru dizzy hole. You could just see it weep a drip after a few moments of pressure. Changed the plug and presto...no leak.

If automatic, then pull the inspection cover and clean the area and start it and watch carefully.

Another possibility is the side seals for the rear cap. Usually would leak right off if it was a problem. They aren't prone to problems, but if you didn't get them in right and sealed well with silicone it might allow leaks.

 

It is definitely rear main. The engine is very clean and dry on top with no leaks. I rang the guys that built the motor and they confirmed it is a 2 piece seal which can be replaced without too much drama. They confirmed it was built 5 years ago, so engine sat that long before the truck was finished. Only the later year cars had a one piece seal that requires removal of engine.
I will get a new seal, remove inspection plate and the sump and see what I can do. With lubrication, the 2 piece seal can apparently be slid around the crank and sealed in to position. Still not an easy job as the motor will have to be lifted up a few inches to remove sump. See how I go.

 

I've done several with the engine in and several with the engine out. Better, in my opinion, with the engine out. Less hassle trying to slide the top half of the seal around and much less hassle trying to keep the oil pan/block mating surfaces dry and clean during pan gask. installation. Also, no monkeying around with the oil pump. Either way you do not have to loosen main caps and drop the crank down a little in order to gain more clearance for the seal to slide in (as I've seen suggested on this forum in the past).

 

Peter it's your call, but you have some bad advice. IMHO

Most every FE built in the last 20 years will have the same seal kit used. There aren't car and truck engines, all FEs are FEs and they all use the same gasket set.

John

 

In the late model motors, the seal can be replaced VERY easily with just dropping the tranny. It pops in the from the rear, so no pan removal and all the work involved with it.

No matter what, you've got some work ahead of you. Personally I think it was installed incorrectly more then any other reason. No reason it should leak today or 10 yrs from now. Unlike a rope seal, it should never dry out and leak.

Make sure when you do install it that you offset the gap in seal and the cap mating surface. A drop of silicone on each end will also help seal it tight. Alot of times I've had to grind the rubber seals for sides of rear cap to get them to fit easily. If not, they get distorted and will likely not bottom out and seal tight.

 

I had every rear leak you can imagine but the rear main. I had to take my engine back to the builder 3 times to get all the leaks fixed and it was never the rear main as I suspected. First ime they said it was a cam galley plug, then it still leaked, then they said it was the rear of the intake, still leaked, then they said it was the oil pan. Finnaly got them leaks fixed. Best to check out all the ways it can leak and check them off one by one so you don't have to redo anything later.