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Rear main seal leaking

  • Thread starter Thread starter Rmoore45
  • Start date Start date Aug 28, 2011
R

Rmoore45

Member
Jun 5, 2011
142
0
17
Aug 28, 2011
#1
  • Aug 28, 2011
  • #1
The rear main seal is leaking on my '66 289 engine, its not a bad leak but there is always a small amount of oil on the bellhousing block plate. I'm using synthetic Mobil 1 15-50, could this be my problem? If I were to switch to a conventional motor oil would that solve my problem?
 
2

2+2GT

10 Year Member
Apr 25, 2009
3,333
10
79
Southeastern Pennsylvania
Aug 28, 2011
#2
  • Aug 28, 2011
  • #2
I doubt it. Oil will find any gap, no matter what the viscosity.
 
R

Rmoore45

Member
Jun 5, 2011
142
0
17
Aug 28, 2011
#3
  • Aug 28, 2011
  • #3
2+2GT said:
I doubt it. Oil will find any gap, no matter what the viscosity.
Click to expand...

The only reason I ask this is because I'm also on a jeep forum and a guy had a problem with his rear seal leaking, he was using synthetic oil. When he switched back to conventional, it stopped.
 

jlangholzj

Mustang Master
Oct 23, 2006
248
31
93
MI
Aug 29, 2011
#4
  • Aug 29, 2011
  • #4
usually if they aren't leaking they're empty....lol mine does this a little as well, I'm running rotella T in mine. I've had it apart and back together...seems like i just can quite get it right apparently. I'll try it again once i put a new stall converter in but for now...little leak
 

PoppyMod

Member
Jun 27, 2010
617
6
19
Severna Park, MD
Aug 29, 2011
#5
  • Aug 29, 2011
  • #5
Rmoore45 said:
The rear main seal is leaking on my '66 289 engine, its not a bad leak but there is always a small amount of oil on the bellhousing block plate. I'm using synthetic Mobil 1 15-50, could this be my problem? If I were to switch to a conventional motor oil would that solve my problem?
Click to expand...


Hi,
I found you may be able to lessen it even more by creating a closed PCV system. I found this helped my situation when running the Holly and full air cleaner. Reducing crank case pressures which, in part, is what a PCV system does in it's recycling, will benefit minor leaks elsewhere, as well.
Good luck!
 
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