What kind of lubricant do you typically use for the various gears in a crawler?

Like the motor and the big gears, and inside the gearbox, and inside the front and rear axles.

There's not much to it, you can buy industrial lubricants or modeling lubricants, the only difference is that if it's related to modeling, it will be very expensive.

The only difference is that if it is related to modeling, it will be very expensive. If you have to buy a modeling lubricant, you can buy this VP (VP Vanquish RC Gear Grease/Lubricant), which is not too expensive, and it comes in a big box, so it will last you for years to come.