No need for high temperature version as stated by others. Brakes contribute to axle heating but most of brake heat is dissapated by air flow. Disc brakes pads drag slightly on disc, but even on my truck in hot Texax summersthere is no evidence of liquifaction or run-out of the grease.

It may be best to cool the hub before backing into the water to prevent sucking water into the hub. I have never experimented with that. Anybody know?

Just found the Mystic JT-6 this morning at a farm supply for $1.69. Bought a case of 10 as my triple axle needs a full bearing service. Bought another grease gun also to dedicate to the trailer.

What about Mercury 2-4-C? It says right on the tube you can use it in trailer bearings (though that doesn't necessarily mean squat) and you probably already have a gun loaded with it. It's what i run - just got back from a 1,000 mile trip with no issues, at least with the bearings.

to Slam;

I don't know that product.
My previous comments were based on a long and successful legacy with Mystic JT-6. Also, based on the opinions of 2 boat people whos opinion I value higher than my own.

Just because they cite it as a wheel grease doesn't make it good. There is a big difference in greases. Get a tube of Mystic and try the "finger slippery" test.