Trans fluid smell in cab

I had to have my manual transmission rebuilt a while back, and when I got the truck back, I noticed a smell of trans fluid in the cab when the windows were down. I took it back and complained and they had the interior completely cleaned and detailed, but the smell is still there.

The smell only happens when the windows are down, and it does not seem to be coming from the air vents. It's like the pressure change is drawing fumes in from somewhere else. I can run the AC, heat or just vent air with windows closed and there is no smell. I don't have a cabin air filter, but I checked the compartment and there is no smell there.

I've pulled the center console and cleaned the top of the transmission to make sure there was no fluid there but that didn't help either.

There aren't any visible leaks under the truck either.
Does anyone have any other ideas where this smell could be coming from?

 

My guess would be they got trans fluid on the outside of he trans, engine, exhaust, cross members, etc... Like gear oil, that stuff smells bad and doesn't go away easily. Get a bunch of cans of brake clean, some safety glasses, and spray the hell out of everything under the truck.

 

Or they got it in the carpet.

Oh and a Manual has gear oil not transmission fluid that is used in an Automatic.

 

I knew that! I have the 6 speed myself! Maybe I should go to sleep?

 

Maybe.

 

Yes, it is gear oil. I've cleaned the carpet with s steam extractor and checked carefully and don't smell any oil. I'll try more cleaning underneath. When I pulled the center console, I noticed the plate over the shifter and the body panel under it were both bent a bit. If anyone has been in there recently, is that supposed be flat, or have a light bend at the back of the shifter? I'm wondering if the gasket is not sealing correctly there.