I'm getting new gears installed and they recommend changing the oil after 500 miles. That's fine for the rear but how do you get that much milage on the front gears. I only go into 4wd when off road and when it snows bad. I probably don't even have 500 miles on the factory gears yet with 78k on the truck. Is it gonna be alright for the front diff gears to start wheeling again after putting 500 street miles on the truck in 2wd.