I just rebuilt my brush deck gearbox. The white lithium grease I had is dupont's white lithium grease with teflon. Bad idea! The lithium part is fine, however the teflon part is very viscous and leaks out the bottom of the gearbox. Eventually it will stop leaking, but in the meantime I have to put a towel under my roomba so it doesn't stain the floor.
Stick to the regular lithium grease, unless you want to put a diaper on your roomba!
the can looks like this: