Rear main seal leak

[tp tbird]

I have posted the trouble I had with my 430 tbird with a rear seal leak before after I had it rebuilt and it is still leaking 400 mile on it.What I was wondering if anyone could tell me if it is possible to see or away to check where it is leaking from with out taking the oil pan off or the engine out?The guy that rebuilt it put a wick seal in it after the neoprene one didn't work ,that only slow it down I have had to take the engine 3 times now.I have been looking around at posts and books and thought it might be the side seals on the rear main,maybe he didn't install them right,but don't know.If I could get it checked somehow to see where the oil is dripping from without major surgery on it.The re-builder suggested a dye in the oil,but I don't know if there is enough room to see it back there if the car is up in the air to see if it is from the side seal or the rear main seal.This guy only has a machine shop so he can't do anything with the engine in the car.Any suggestions?

[Rigormortor]

If it was me..... I would pull the engine and replace the seal correctly.... alot easier than trying to do it with the crank still in the engine. It should be easy to pull that engine out of the car. I replaced one in my Dodge 383 and it has been great since the rebuild.

[partsetal]

Even with the pan off it would be extremely difficult to determine if the side seals or the crank seal were leaking. Their proximity would only show the presence of oil. Possibly, with the pan off and the oil galleys pressurized, you might be able to see an active leak, but with all the other oil, it would be difficult to pinpoint it.
You didn't mention how you knew it was a rear main seal leak. Did you see engine oil dripping from the bell housing? Was the back of the oil pan wet? If it was engine oil from the bell housing, it could also come from the pressurized area around the rear of the camshaft. If the pan was wet, I've seen valve cover gasket leaks that would do that.
Carl

[Guest]

Main seal ...

Before pulling the engine I would pressure wash the engine paying particular attention to the rear of the intake manifold and rear of the heads, also the pan rails and timing cover. Then find someone with a lift and add some dye to the oil and let the engine come up to operating temp. Now using a black light (inexpensive incandescent ones available at Wal-Mart) carefully examine the entire engine top, sides and bottom. almost any engine leak can appear to be a rear main. Rear of the intake is a common culprit, Ive also seen distributor and timing cover leaks that would seep down the pan rails and appear to be coming from the rear main. That being said it could still be the rear main, but it would be a shame to pull the engine, redo the rear main, reinstall it and and still have the leak. Mike

[60 T-Bird]

I agree with Mike, Tom. It just doesn't make any sense that you have dealt with it that many times and still have the same deal going on...Martin

[simplyconnected]

Three seals failed? Upon inspection, were the seals chewed up? I've seen rope seals with sections missing!

If your crankshaft is nicked and left that way, it will destroy your seals. The only way to fix it is to take the cap apart and carefully stone the crank, smooth.

Otherwise, if your leaky seals looked ok, I agree with Mike... put dye in the oil and watch with a black light (just like at the engine plant). The slightest leak will show up, white. You won't see it too much between the flywheel and engine because they are so close, but a leak leaves a witness trail.

Carl raises good points, too. How much oil is leaking? It could be from the cam plug, etc. We need more info.

It's always easier to fix a rear seal with the flywheel off and the crank dropped slightly. It helps to run the engine out of the car on a cradle, and let it get hot enough to open the thermostat. Cycle it a few times. Usually, problems show up right away.

[tp tbird]

Rear engine leak

This guy that re-build the engine has been doing engine for a long time ,but only has a machine shop and no place to work on cars.I had the guy put in a neoprene seal in that I had to get from a tbird parts book for a 430 engine when he rebuilt it. The 2ND time I took the engine out was due to a oil plug in the rear of the engine he said and the engine would have to come out to fixed the plug ,so I took it out took the engine back to him to fix then I had to put it in and together ,when I started it it was still leaking under there.So he took it to a shop next door and took the trans out and dropped the pan and tried a small brass shims under the seal and they still looked good ,that did not work but it did slow down some .So I got the car back home he said to take the engine out again he would put a wick seal in.I got it back to put it back in and together and started it and it still was leaking but not as bad a drip about 1 every 15 to 20 seconds this time.He said he put a drill on the oil pump true the distributor and he didn't see any leaking.Now with some miles on it and it is still that way.It is coming right from the rear of the engine and bell-housing.

[partsetal]

FWIW, There is a photo of the galley plugs used around the cam plug on the 430 at: http://ford-mel-engine.com/download/file.php?id=714&t=1
I offer this because I had been prepping a rebuilt 430 (but never run) to run. When I charged the oil passages with oil (engine on an engine stand) I noticed oil leaking from the rear of the motor. Upon investigation, I determined that whoever rebuilt this motor (25 years ago) removed the small galley plugs but never replaced them. I installed them and tested again, then found that one of the plugs popped out. I used a different plug and it withstood the pressure.
Could this be what you're experiencing?
Also, I don't understand where your rebuilder added brass shims.

Carl

[tp tbird]

FWIW, There is a photo of the galley plugs used around the cam plug on the 430 at: http://ford-mel-engine.com/download/file.php?id=714&t=1
I offer this because I had been prepping a rebuilt 430 (but never run) to run. When I charged the oil passages with oil (engine on an engine stand) I noticed oil leaking from the rear of the motor. Upon investigation, I determined that whoever rebuilt this motor (25 years ago) removed the small galley plugs but never replaced them. I installed them and tested again, then found that one of the plugs popped out. I used a different plug and it withstood the pressure.
Could this be what you're experiencing?
Also, I don't understand where your rebuilder added brass shims.

Carl

When I saw the leak after he rebuilt it he said it had to be one of the oil plugs on the back of the engine,so he replaced it and run oil pressure to the engine and said it was fine. The shims he put after I put it back in and ran it and still leak were under the neoprene seal to tighten the seal to crank journal,but that did not work.Tom

[tp tbird]

link

FWIW, There is a photo of the galley plugs used around the cam plug on the 430 at: http://ford-mel-engine.com/download/file.php?id=714&t=1
I offer this because I had been prepping a rebuilt 430 (but never run) to run. When I charged the oil passages with oil (engine on an engine stand) I noticed oil leaking from the rear of the motor. Upon investigation, I determined that whoever rebuilt this motor (25 years ago) removed the small galley plugs but never replaced them. I installed them and tested again, then found that one of the plugs popped out. I used a different plug and it withstood the pressure.
Could this be what you're experiencing?
Also, I don't understand where your rebuilder added brass shims.

Carl

I tried to go to that link but it won't let me see it ,I am a member there.

[partsetal]

I rechecked the link and it worked for me. The photo is in the engine section, several pages back under the heading 'galley plugs'.
I understand about the shim now.
It is very easy to install the neoprene or the rope seal improperly, and you don't know if it will work until you run the motor.
If the oil was coming from the vicinity of the cam plug, you might be able to see the back of the block by removing the bell housing access plate. There is not a lot of room there, but perhaps with a pinpoint light and a small mirror you may be able to see if the back of the block is wet in that area.
Carl

[tp tbird]

I rechecked the link and it worked for me. The photo is in the engine section, several pages back under the heading 'galley plugs'.
I understand about the shim now.
It is very easy to install the neoprene or the rope seal improperly, and you don't know if it will work until you run the motor.
If the oil was coming from the vicinity of the cam plug, you might be able to see the back of the block by removing the bell housing access plate. There is not a lot of room there, but perhaps with a pinpoint light and a small mirror you may be able to see if the back of the block is wet in that area.
Carl

This is what I get when I click the link (You are not authorised to view, download or link from/to this site)I do see the gallery part there and picture of the plugs at the mel site

[tbird430]

You other fellas need to also know this "leak" has been going on for almost a year now. The O/P (original poster) is older & is having to R&R this big 430cid engine on his OWN.

Sorry for interrupting "tp tbird", but I know this problem has really been a thorn in your side for quit a while now. I remembered your original post many months back too. I just felt the others needed to know this...

Good luck.
-Jon in TX.