Rear main seal

[RustyRatRod]

Well, i assume he's not gonna like me taking a pi$$ on his pristine driveway then. And if I'm in somebodies driveway, they better have beers. At my age it's a 2 beer bladder limit

Well, the sad fact is, they don't stay leak free. Period. Now, were they redesigned with one piece rear seals, they'd stay leak free longer......but they still eventually leak. As someone said elsewhere, the only way to be leak free for good is to not put oil in it.

 

[CRUZE 418]

Not in my driveway. I hate it when when someone comes to my place and bleeds oil all over the drive.

 

[4spdragtop]

Yeah, how much difference in enjoyment is there between the odd drip vs $$/energy/time involved in spotless.
I've been replacing front end stuff and noticed a couple moist spots on engine. Only been in for a season, not gonna sweat it until I need to.

Well, the sad fact is, they don't stay leak free. Period. Now, were they redesigned with one piece rear seals, they'd stay leak free longer......but they still eventually leak. As someone said elsewhere, the only way to be leak free for good is to not put oil in it.

 

[hcarr]

Inspect the oil sender location just behind and to the passenger's side of the distributor. Leaking sending units are responsible for a LOT of misdiagnosed leaking rear seals, because the oil runs down the bellhousing area of the block and ends up dripping in the same place as the rear seal.

You are 100 % right Rusty.I had that happen on my Duster. I thought it was the rear seal but discovered it was the plastic line on the back of the sending unit leaking and I was just getting ready to pull the motor! Great call!!!

 

[middleagecrisis]

What if that drop is on your buddy's brand new pricey concrete driveway? We all make priorities. When engine building, my priority is do it right.

I kinda get what you're saying, but very glad you're not a surgeon. lol.

Even though I'm not a surgeon, I'm actually very detailed in my chosen profession (Logistics) and drill down to details many don't consider. Just because I don't sweat a drop of oil under my Duster, doesn't mean that I half-a$$ things. Read my question in the SB engine forum about balancing a rotating assembly. I'm considerate enough to not park on a brand new driveway if I've got a leak. My Duster turns heads, but I'm not afraid to park in the street, if needed.

 

[RustyRatRod]

You are 100 % right Rusty.I had that happen on my Duster. I thought it was the rear seal but discovered it was the plastic line on the back of the sending unit leaking and I was just getting ready to pull the motor! Great call!!!

I bet you were really glad, too!

 

[Swinger 340]

Inspect the oil sender location just behind and to the passenger's side of the distributor. Leaking sending units are responsible for a LOT of misdiagnosed leaking rear seals, because the oil runs down the bellhousing area of the block and ends up dripping in the same place as the rear seal.

I thought I had a leaking rear main seal once, by where it was dripping. Once I got under my Dart for inspection, I noticed a pin whole in the oil pan. I drained the oil, clean the location, sanded the paint and "JB welded" it. It has been 6 years now, no leaks yet. It's a 36 year rebuild. Just a note: The OP says he uses a 50/50 mix of coolant. Does he use premix or add his own water. He needs to use distilled water as one of the 50. City water will eat and plug up the cooling system.