Oil leak between transmission and engine

[darkomesaros]

Heya TJ friends,
I have a 2004 TJ (Automatic 4.0 Inline 6) which seems to be leaking oil (very very slowly) between the engine and the transmission.

My oil levels are okay, and over the span of two weeks I have just a small dark spot in my drive way. How big of an issue is this and how complicated of a fix? Me not being a (real) car guy, I am yet to attempt to fix such an problem.

 

[Tob]

Most likely the rear main seal, but could be the rear of the valve cover gasket.

Read the first couple posts of this thread on rear main seal replacement (not the whole thing).

https://wranglertjforum.com/threads/rear-main-seal-replacement-4-0.826/

 

[darkomesaros]

Most likely the rear main seal, but could be the rear of the valve cover gasket.

Read the first couple posts of this thread on rear main seal replacement (not the whole thing).

https://wranglertjforum.com/threads/rear-main-seal-replacement-4-0.826/

Thank you Tob! This is what I was looking for!

 

[inkedrose]

Before you start pulling parts do an oil change. Use high milage conventional oil, not synthetic. I had a similar problem year or so ago. After recommendation here I switched it up an haven't had a problem since

 

[Apparition]

Before you start pulling parts do an oil change. Use high milage conventional oil, not synthetic. I had a similar problem year or so ago. After recommendation here I switched it up an haven't had a problem since

 

[Moglocker]

View attachment 648961

He’s living rent free app!

 

[Apparition]

He’s living rent free app!

I wanted his head on this gif but didn’t feel like making it.

 

[inkedrose]

View attachment 648961

He’s still in a FB forum I’m in

 

[inkedrose]

I wanted his head on this gif but didn’t feel like making it.

View attachment 648974

how has that not been done yet? Slacker!!

 

[darkomesaros]

Before you start pulling parts do an oil change. Use high milage conventional oil, not synthetic. I had a similar problem year or so ago. After recommendation here I switched it up an haven't had a problem since

That is a great idea. I did not intend to make the fix really soon, so I may as well just try that!

 

[darkomesaros]

Before you start pulling parts do an oil change. Use high milage conventional oil, not synthetic. I had a similar problem year or so ago. After recommendation here I switched it up an haven't had a problem since

Oh, I may try that! I did find some Castrol oil on Amazon that seems to be "conventional". Is this what would work well?

 

[Moglocker]

Oh, I may try that! I did find some Castrol oil on Amazon that seems to be "conventional". Is this what would work well?

Dollar general usually has this in stock

 

[Link]

It doesn’t matter if it’s synthetic or not. But it needs to be high mileage rated. I use inexpensive Super Tech 5W30 High Mileage synthetic and change more frequently.

Also if you have a decent leak, toss half a bottle of this in at the next oil change and 1/4 bottle in at the next two changes. Then just high mileage rated oil in whatever brand makes you happy. This additive will speed up the softening of the seals.

https://www.walmart.com/ip/STP-High-Mileage-Oil-Treatment-Stop-Leak-15-FL-OZ/19897926