Greasy/oily cv boot but everything else is clean

I pulled the wheels off of our 14 Honda Odyssey for new tires and everything is pretty clean except for the pass inner cv boot.  It is covered in an oily/greasy sludge but nothing else is.  There are no cuts or tears that I can see and there is no grease or gunk that has flung off of it. 

It looks like the grease has just seeped through the rubber....  pretty strange.   Anyone have any ideas what could cause this???

Degradation of the rubber of the boot allowing grease to seep through, possibly just from age and normal environmental wear, maybe from using the wrong grease inside, or just touching the outside with the wrong grease (possible brake fluid/engine oil drip?). Change it quick before it spews everywhere!

Drip from above?

That adjacent oil filter location looks like it could have contributed to spreading some oil around at some point in the past. I would wipe down the boot and see if the gunk returns after a little more driving.

yeah wipe it down.. see the condition underneath. if it returns then you have a problem..

Baked... from the 120+ deg of exhaust that runs around it.  Softens the rubber turns grease to oil.  Leave it be, if you try to clean it it will meltaway.

44Dwarf said:

Baked... from the 120+ deg of exhaust that runs around it.  Softens the rubber turns grease to oil.  Leave it be, if you try to clean it it will meltaway.

I was thinking heat could be part of the problem after looking at that exhaust routing...could be a good use for some of that formable corrugated exhaust heat shielding.

It’s nothing that has dripped on it as everything around is clean and there is zero splatter as if oil dropped and got flung off. 

I think the heat from the exhaust is a good call as to causing the issue. 

I pressure washed everything and the boot is now clean. I’ll keep an eye on it. 

Thanks for posing a possible (and probable) explanation!

I don't know if these axles are like Subaru axles, but in that world very few aftermarket replacement axles are as good as oem. Axles are cheap and easy to reboot and you get to keep your good oem units. Also check to see if yours are interchangeable left to right. If they are you can swap them and prolong their life even more. The tripod joints tend to wear mainly on their respective drive sides.

That looks like seepage from behind the timing cover to me. It happened on ours. Do you have the cylinder deactivation motor?