oil leaking from rear main

[pokeyman]

After switching to mobil 1 synthetic oil i develop an oil leak in my rear main seal. The truck does have over 200000 mile on it . I was wondering if any of you guys had the same problem after switching over to synthetic oil.

 

[sawguy]

Could be coincidental. I switched over a few years ago with no leaks. My 96 has 250k and my 97 has 280k.

 

[3bears]

agree, I think it is a coincidence

 

[HiLife]

Because synthetic oil does a better job of cleaning out sludge, it could remove deposits that are acting as seals when conventional oil was used.

 

[aontkos]

It’s been said a lot here and I’ll gladly perpetuate it, but make sure it’s actually your rear main seal and not just a leak in your valve cover or half moons.

 

[jgue467]

Because synthetic oil does a better job of cleaning out sludge, it could remove deposits that are acting as seals when conventional oil was used.

Myth or old wive's tale, take your pick. :cowboy:

 

[nissanh]

If you are sure it is the rear oil seal, try AT 205 additive.