Anyone know what might be causing this?

[trx300cw]

On my trx300fw it's an 88 model, the front differential oil is coming out of the top of the vent line and dripping down on the top of the engine. It only does it when going at higher speeds for a mile or so. Anyone ever had this problem or heard of it happening? Thanks in advance

[jrafter]

did you over fill it

[trx300cw]

Don't believe so. it has been in there for a few months with no problems until now

[jrafter]

i would still drain it might have gotten water in it

[Whiskey Tango]

Absent something mechanical causing an overheat condition (not likely) the fluid level is too high - because of one of two factors: too much oil installed or oil level sitting too high because of water underneath it.

Ditto on the advice to flush and fill with exact proper amount. If water comes out - maybe flush a few times.