Serious oil leak - rear main seal?
 

A friend brought his car over for me to help him get it running better (points were very rough and even loose). Once we got it running nicely we left it running for a while. Then I noticed a huge oil spill under the car - more than a foot diameter after 10 minutes running.

Take a look at this video. Oil is pouring out of side of bell housing.

After shutting it down, I checked the oil, and it was even a tad overfull. When I inquired, my friend said he had changed the oil a couple weeks earlier. I suspect he may have put to much oil in it and it is just puking out the extra.

Or, did his rear main seal suddenly disintegrate (engine was last rebuilt 50 years ago).

Appreciate any thoughts you might have.

Hope this youtube link works and you can see the oil pouring out.

https://youtu.be/B8TBe-bcJYo

Re: Serious oil leak - rear main seal?
 

Wow... did he name the car Exxon Valdez :D

First, the hole in the flywheel housing is mildly concerning, not related to the leak but concerning none the less.

There is no real seal in the modern sense, the oil that makes it to the back of the bearing should get caught in the slinger and then funneled back to the sump. Wear in the rear main will let more oil through and will overwhelm the slinger and just slip right past and onto the ground.

Did you check the oil level on the dip stick?

Did you check the breather cap for an obstruction?

How does the engine run otherwise? Is there a noticeable amount of end play? On my old engine there was about 1/16" and it only left a few drops. For reference I believe the max. tolerance specified is .006".

Re: Serious oil leak - rear main seal?
 

Maybe the oil return pipe was missing or fell off when he had the pan off.
Also what's going on with the radius rod socket?

Re: Serious oil leak - rear main seal?
 

Thanks Ryan,

I have no idea what is up with that hole in the flywheel housing. It kind of looks like a factory made hole, but I've never seen that in other model As (including the 2 in my garage now). I can probably find a rubber plug to put in there for him to keep mud from getting in there ...once we've taking care of oil leak.

After I videotaped, I shut the engine down and checked the oil was - it was full - even after leaving about a quart on my garage floor.

The breather cap seemed fine, but I removed it and let the engine run for another 5 minutes with no cap, and it still poured out of the housing.

I did not check the end play in the crank. What is a good way to do that while engine is in the car?

Thanks again!

Re: Serious oil leak - rear main seal?
 

He hasn't had the pan off during his ownership (25 years!).

Regarding radius rod, this has been a driver quality car for 50 years. There are a number of minor modifications that have been made over the years. I've not tinkered with radius rods yet, so I need to ask - What looks so far off to you on this? Missing spring under the nuts? Too much grease?

Thanks again for your help

Re: Serious oil leak - rear main seal?
 

On that hole, odds are one of the bendix bolts worked loose and then punched its way out of the flywheel housing. I've seen it before. If the rest of the housing is okay then it's not the end of the world.

Sounds like it might be worth draining the oil, pouring in 4 quarts and seeing if it still does it. You can check the end play at the crank pulley with a dial indicator. If the end play is even remotely close to spec then I'd start to imagine that rear main bearing itself may be seriously compromised. How many miles are on this engine?

It could be coming from the cam I suppose but I doubt it would leak that much if that was it.

Was really hoping someone stuffed a rag in the breather cap. Easy fix!

Re: Serious oil leak - rear main seal?
 

I misread your original post, I see you said he change the oil not the pan gasket. I see something the red arrow is pointing to, looks strange. Are the springs missing, looks like it.

Re: Serious oil leak - rear main seal?
 

I'm not sure what that is. Like I said, there are lots of non-original items on this car - it looks like they pieced things together with whatever they could find at the time.

Re: Serious oil leak - rear main seal?
 

Yep, I agree that draining the oil and starting with putting back in 4 quarts or until it is at most halfway between low and full.
Also check to make sure you don't have a coolant leak into the oil.
If an oil leak of that size is being caused by coolant in the pan it will be easy to spot.

Re: Serious oil leak - rear main seal?
 

Re: Serious oil leak - rear main seal?
 

I agree with the two posts above and would add one comment. Make sure the dip stick is being fully inserted into the hole, not just to the end of the handle.
That could be the whole problem from the beginning but I don't recall anybody mentioning it.

Re: Serious oil leak - rear main seal?
 

That is a very good point. I do wonder if he didn't have the dipstick in all the way and kept adding oil.

I'bee offered to go to his place and change the oil, but I think he was planning on putting into storage tomorrow. I'll let you all know if I get my hands on that A one more time before he puts it up.

Re: Serious oil leak - rear main seal?
 

Re: Serious oil leak - rear main seal?
 

Appears to have simply been overfilled oil. My friend had taken the A to a quick oil change place! I was stunned that he would trust those guys to his A.

Regardless, by the time my friend got home from my place, the A was no longer spewing oil. He let it run for quite a while and still not leaking. And when he checked the oil, it was right at full.


Thanks everyone!!

Re: Serious oil leak - rear main seal?
 

Never trust your Model A to amateurs. Never.

Re: Serious oil leak - rear main seal?
 

I agree 150% with that. The service departments at dealerships would have you believe they are anything but amateurs but when it come to a simple car like a Model A, they have no clue.
I bought a 1930 CCPU out of Phoenix a few years ago and the seller took it to the local Ford dealer before he advertised it. You wouldn't believe what I found when I got it home.
It was almost undrivable and you certainly couldn't drive it safely. The brakes were the worst I have encountered on any Model A I have seen although they had just been relined. A new clutch and ring gear had been installed with the ring gear put on the flywheel backwards. They put the usual sticker on the windscreen showing the mileage for the next oil change - 3,000 miles later. 3,000 miles on an engine with no oil filter! Utterly clueless.
There is more but I think you get the picture.