Reese trunnion bar oil - where to buy it?

I just use a light dab of wheel bearing grease. I use it on the ball, and trunnions. works great.

Listen to the sage advice above; there's nothing magical about Reese Grease. I've got white lithium, Red Mobil 1 Synthetic, and Black disc brake grease and have used all of them over the years. The only real issue is what color you want on your pants.

There's nothing special about the Reese grease. Any generic white lithium grease from an auto parts store is just as good and a whole lot cheaper. You can even buy the stuff at WalMart.

The white lithium will do the job on the trunnion bars as well

Any motor oil would be fine. You would not want to use an oil like 3in1 or sewing machine oil as it would be too thin. However, since you already have the Reese lithium based grease I would put a dab on the top and bottom of the trunnions and call it good. Also make sure you use it on the ball too! Actually, any good wheel bearing or other grease from a grease gun would work fine. Just don't run it bare!
Barney