Oil leak from hell on my 360!! Help me!

[Dr. Righteous]

The 360 I built back in the summer has been leaky the entire time. It has been the oil pan leaking from the drain plug (somebody crossthreaded it at one time I am sure) and the the pan gasket rear and sides.
My first attempt was to crawl under and tighten all the bolts. No luck. Still leaked! The pan was a little beat up so I was suspicious of the pan.
Ok, Step two. I ordered a new MP stock replacement oil pan kit. ($80 for a stock non baffled pan! Good Grief!) With pan and new gaskets in hand I changed them out. I pulled the old pan and it looked like the cork gasket on the sides of the pan had spots that didn't seal at all. I concluded from this that the pan was warped and refused to seal. (seen that before) The front and rear rubber seal looked ok but I replaced them anyway. I used 'gasket tack', just enough to keep the cork in place while I installed the pan. All back together, looked good. I oiled her up and test drove her the next morning. When I got home I checked for leaks.
OIL ALL OVER EVERYTHING! I was afraid I had a rear main leak also and this confirms it. Oil only seemed to be leaking from the very rear of the pan now, where the tranny bolts up. When I built then engine I was very careful to install the rear seal as the instruction said. I didn't install them backwards. Now that the engine is in the truck, how do I get to them to check them? How would I change them out? Do I have to remove the crank???
Can I just drop the rear main cap and change the seal?
Some of you that have delt with the problem on a Mopar small block let me hear what you think ok??

[10sec340]

when i put in my 2" headers, the big hamburgh pan didnt fit anymore, so the (fu-k off) shop put in a little 7 qt. milldon pan and matching oil pump/pickup...when they removed the rear main cap ,to change the windage tray,to do this... the seal leaked,only a slight bit and we thought it was the pan, then summer rolled around and the car was driven everyday,boy did it leak!!!!!
a real good shop(MASTERCARE in oceanside) did the rear seal change with motor in car and crank stayed in, only charged me $75 plus the seal and gaskets!!
good luck

[dave571]

Pull the pan, and the rear main cap.

Modern lip seals are easily changed, no special tool's required.

Just make sure ther's no oil under the cap when you torque it back on again.

[Dr. Righteous]

Yeah, I know what you mean 10sec340. This thing leaks a lot of oil. The entire undercarriage is drenched and the mist from the oil hitting the road has fogged up my rear window. My drive way is totally oiled down and looks nasty. But the truck runs sweet and is such a ball to drive I hate to leave it parked. I have to get this thing fixed once and for all! Funny thing is it would seem to quit leaking for a while; or would only leak a tiny bit. I changed to a stright 30W oil and it seemed to stop leaking accept for the very slight leak from the boogered up drain plug. I didn't have to add any oil for a long time. Cool! I thought. Well my girlfriend and I took off on a trip to Florida for vacation and on the way down the Ramcharger started pissing oil like crazy!!! There was oil smoke boiling out from under it! I had one guy try to flag me down as he passed me to tell me that it was smoking badly. I had to add a half quart every time I gassed up. I tried to calm my girlfriend down by telling her that it was a oil leak, nothing serious and that I was on top of it. She was scared that it was going to blow up or something.

[dave571]

Before you get too crazy, look higher up the engine. Make sure it isn't an oil sender or something, running down the back of the engine.

Rear main seals are the most often Mis-diagnosed oil leak I've ever seen. It's been my experience that only about 10% of rear main leaks(diagnosed prior to coming to the shop) are actually rear main seal leaks.

It could be leaking, but there's easier stuff to check first.

[Leigh]

Clean it and dye it. Sure saves a ton of time.

[George G. Leverette]

I agree that the oil sending unit and the distributor are sources of leaks that are hard to detect, suggest some simple green undiluted be sprayed on and washed off to determine the source of the leak. If it is a main seal Pep oys has a removal\install tool for about $10.00 and the seal costs about the same less than a hour later you can change the seal.

[deadhorse66]

Originally posted by Leigh
Clean it and dye it. Sure saves a ton of time.

Here's a man with some good common sense. I like to use blacklight dye. You can get it for about $10 a bottle. It is a little expensive, but i bet you have already spent that much on topping the crankcase off every time you fill up!