Oil Pan Flatness - How Far Off Until Issues?

[LngJeep]

Hi all , just pulled the oil pan to replace the gasket. It had a steady seep (purchased this way late last year). During re-assembly (will be using Fel pro), I noticed that the pan isn’t 100% flat to the engine. I took it back off before adding any bolts. Laying it on a flat concrete slab and capturing the passenger rear corner, the driver front corner has maybe an 1/8 - 3/8 of gap. I get the same results against the blocks without the gasket. The pan isn’t very rigid so I suspect that slack will be taken up when the bolts are tightened. The flip side is the bolts are very low torque and I’m wondering if the flatness could have contributed to the leak.

I’m hesitant to reinstall until I get some feedback from others with experience. If it’s no good, I’ll be looking at used OEM pans unless someone has a brand they prefer.

Thanks

 

[TJ Jim]

Hi all , just pulled the oil pan to replace the gasket. It had a steady seep (purchased this way late last year). During re-assembly (will be using Fel pro), I noticed that the pan isn’t 100% flat to the engine. I took it back off before adding any bolts. Laying it on a flat concrete slab and capturing the passenger rear corner, the driver front corner has maybe an 1/8 - 3/8 of gap. I get the same results against the blocks without the gasket. The pan isn’t very rigid so I suspect that slack will be taken up when the bolts are tightened. The flip side is the bolts are very low torque and I’m wondering if the flatness could have contributed to the leak.

I’m hesitant to reinstall until I get some feedback from others with experience. If it’s no good, I’ll be looking at used OEM pans unless someone has a brand they prefer.

Thanks

Pics to clarify what you are seeing?

 

[BlueC]

Laying it on a flat concrete slab and capturing the passenger rear corner, the driver front corner has maybe an 1/8 - 3/8 of gap.

That's quite a bit and likely why you're leaking. Get a flat section of 2x4 and a hammer to straighten it. (hammer & dolly)

 

[macleanflood]

This far...

-Mac

 

[LngJeep]

@TJ Jim Good call should have posted that. This is with the passenger rear side held down (picture is driver front). Has slightly more play when holding against the block (likely flatter than my floor).

@BlueC Good call, not much too lose and likely a small tweak will be enough

@macleanflood Ha if you can pull that off I should be able to make it!

 

[Zorba]

This far...

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-Mac

You da MAN! Dropping the pan in a dirt parking lot to fix the dent - those guys in India don't have anything on you!! I wouldn't even THINK about doing that - but I do have that exact same oil catch container, so there's that...

 

[SkylinesSuck]

This far...

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-Mac

Good thing 4.0s come with those handy dandy sub-oil pan engine skid plates!

 

[LngJeep]

Update:

Did some light work on the pan and reduced the bow by about half. I mounted it and used small, but strong spring clips on each corner to get everything flat. Then bolted up no problem. It’ll be a couple weeks of other work before I can test it but I’ll keep everyone posted. Thanks!