gear oil problem

Hello, this came out of my gear box oil. It's grey looking something. The oil is 6 weeks old. What could it be? Thanks

looks suspiciously like a socket!

Typically a milkshake looking fluid indicates coolant mixing with the gear oil. I'm no expert but the first place to look is usually the water pump seal.

100% water in oil

Either what Dauer said or you submersed your engine in a water crossing and had not a carter breather hose on it (ask me how I know )

Robert-Jan

Thanks. Which seal should i check,The one behind the water pump rotor?

Happy to help when I'm able or qualified (which is seldom). Yes, again I'm no expert but the seal behind the impeller is typically the cause of water leaking into the gearbox.

When you hit a water crossing with a warm engine the engine rapidly cools and water is sucked in through the trans breather hose. You can run the breather hose to a higher location like the air box or drill a tiny hole in it near where it goes in the engine to keep it from siphoning. The water won't hurt much as long as you don't leave it in there, it's happened to my WR250 several times, I'd just change my oil and keep riding.

i didn't ride near water so that's no an option.
i toke the impeller out and the seals seams okay, i will replace them just to make sure, but i was wondering if there's another seal that i should look for that might cause the problem?

NOPE JUST ONE WHATS THE SHAFT LOOK LIKE A SIMPLE PRESSURE TEST OF THE COOLING SYSTEM WILL TELL YOU FOR SURE IF ITS THAT OR A SUCK JOB CONDENSATION CAN ALSO HAPPEN IS THE COOLANT LOW

Your photo does look like water in the oil. I have a YZ125 with Barnett clutches and every oil change looks a terrible gray similar to yours but it's clutch dust suspended in the oil. Like Troy said check the coolant level, it might also be possible that the case halves could have a seep of coolant where the coolant crosses although I can't say if it would leak in to the trans oil or the cavity where the crankshaft is.