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69 Block rear main seal

  • Thread starter Thread starter 1slow95
  • Start date Start date Mar 30, 2008

1slow95

Founding Member
May 16, 2002
1,797
3
48
ohio
Mar 30, 2008
#1
  • Mar 30, 2008
  • #1
I'm getting tired of the puddles of oil under my car. I pulled the engine out 2 years ago to change the oil pan gasket because it was leaking almost like it didn't even have a gasket. Now I get a small drip while the car is running and I always end up with a decent sized puddle after it sits overnight. I'm not sure exactly where it's coming from, but I suspect it's the rear main seal.

My problem is the 69 block has a 2-piece rear main. Since this was my first engine build, I didn't realize you were supposed to put a dab of RTV between the 2 pieces... I assume that would cause a leak? If that's where my problem is, can I change just the seal? I need to pull the main cap off to get to it and I don't know if I can do that without changing the main bearings?


The reason I'm contemplating pulling the engine to fix this is because I plan to change my exhaust soon, and removing the headers is just about the hardest part of pulling my engine. (Other than removing all those stupid bolts in the scattershield....)
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
3,133
18
108
Chicagoland
Mar 30, 2008
#2
  • Mar 30, 2008
  • #2
You could reuse the bearing if it's in good shape. It would probably be easiest to pull the engine though, because it's about the same job as doing an oil pan gasket, except the pan needs to come completely out for the job. I would think it could leak without some RTV between the two halves, but I can't say for sure.
 

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
Mar 30, 2008
#3
  • Mar 30, 2008
  • #3
with KOOKs, i thought removing the headers was easier than with one piece headers?

but i have heard of people replacing the rear main seal without removing the engine. not sure how much harder it would be in your case though. what with the fact that it is a 351 block instead of a 302 block ...
 
H

hookups333

New Member
Sep 20, 2005
154
0
0
Jax Florida
Mar 30, 2008
#4
  • Mar 30, 2008
  • #4
302 block is easy to change rear main it has a one piece rear main his sounds low 5.0's is alot different.
 
9

95Mustang302

Member
Mar 30, 2005
302
0
16
Mar 31, 2008
#5
  • Mar 31, 2008
  • #5
yeah, low has a 69 block poked and stroked to a 418, its only "slightly" different than a late model 302, LOL
 

1slow95

Founding Member
May 16, 2002
1,797
3
48
ohio
Mar 31, 2008
#6
  • Mar 31, 2008
  • #6
BlackVert said:
with KOOKs, i thought removing the headers was easier than with one piece headers?

but i have heard of people replacing the rear main seal without removing the engine. not sure how much harder it would be in your case though. what with the fact that it is a 351 block instead of a 302 block ...
Click to expand...


Yeah, the Kooks aren't too hard to remove, but it's still the hardest part of pulling my engine.

The older blocks look something like this...As you can see there's no way to get to it without removing the main cap.
 
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