I was just under my car today to change the oil, and noticed a gooey, tar-ey black substance on the bottom side of the transmission housing. At first I thought it was caused by an exhaust leak somewhere along a cat, but that is not the situation. It is not coming from above, either, since the top of the housing is totally clean. It now looks to me like there must be a transmission fluid leak from one or both of the bungs on the housing?

I was just under the car 1000 miles ago, and didn't notice this. So, I have caught it relatively early.

Anyone with more experience have any idea what's wrong or how serious this is?

 

Looks like normal road dirt to me

Is it on both sides of the trans in the same area? If so, I wouldn't worry about it.Also, is this your first summer with this car and is this your first car ever?

 

Nope, neither. I suppose it's possible that it's road dirt, but it feels and smells oily. Also, if it came from underneath, then I would expect the ground-facing sides of the O2 sensor plugs and lines to be dirty, but if you look at the pics, they're totally clean. In fact, they're actually dirty on the side facing the transmission housing. I think it's unlikely the residue came from underneath.

 

Wow Ordovician, I wish the inside of my Z was as neat and clean as the underside of your Z!

 

Thanks! I am just worried I'll have to go CD009 sooner rather than later. Sucks because I had my heart set on fixing up my Xterra and getting a new rifle

 

i wish the inside of my Z was as neat and clean as the underside of your

 

Yea unfortunately thats what might be the case.Its too clean on the other sides. My integra has the similar look..almost like pooled oil inside. Its a auto and starting to shift hard...Is it slipping or anything? or do you smell burning oil after driving any at all?

 

looks to me like something could have splashed up...if your not having any mechanical problems i wouldnt worry too much.

 

Looks like oil with dirt in it.

Oil change recently? any oil down the back of the engine spilled?

 

Not slipping, but the syncros could be a little crisper. Nothing terrible though. The clutch might be a little stiffer than normal, though.

See my post earlier, I just can't see how anything could splash up there without dirtying lower areas.

Could be, but I can't determine the path it would have taken. Seems confined to the transmission housing.

 

If it was leaking it would be wet and or slightly tacky to the touch.

 

If anything it looks like it would come from the right wheel while turning depending on your speed would determine where it splashes

 

Almost looks like fuel. Check your injectors/rails and other stuff in the rear of the engine bay.