500 miles under 50 mph

The break in period is for the gearset and not the engine. I would head the 500 miles without towing recommendation. I would ignore the under 50MPH though once you begin towing...

I would do what they say, and change the rear axle oil after the break-in period.

You don't want to have to buy a new gear set and go through breaking it in all over again, because you were too stupid to break it in the way they tell you...

Not a big deal. The GM I used for towing had the same instruction. I followed it, just took the tow vehicle and trailer on a low traffic secondary highway for the 500 miles. We were going camping at the spot which was a bit more than 500 miles away. By the first day it was broken in for towing.

My view is follow the manufacturer's instructions. I always break in my vehicles according to what the maker says and then some. So did my dad.

I also don't run the vehicle at a constant speed while breaking it in, and back off the throttle every so often to change rpm.

It pays off in the long run.

Just stay off interstate, it's not hard to do.

Or take advice from random strangers that contradicts your manual.

Your money, your choice.

SoCalDesertRider wrote:
I would do what they say, and change the rear axle oil after the break-in period.

X 2.

All the replies will be anecdotal. One person saying they always do what the manual says and has no issue proves nothing. Just like one person posting they never do what the manual says and never have issues. It's all opinion.

Yeah, I will follow the manual and take the secondary roads for a awhile. Pain in the rear, but I figure the engineers know more about the truck than I do. Though I never read anything about changing out the rear end dope after the break in.

Mine was delivered to me from 100 miles away, all interstate driving for the guy who delivered it to the dealership. Oh well... I figure as long as it's not really abused and driven a little more conservatively, it should be fine. The 6.0L is known for reliability.

Besides, it's only ONCE.

Food for thought... I am a police officer. My last new car was a 2007 Crown Vic that was delivered to me with 87 miles on it. Day 1 of having it I was driving it HARD and never followed a proper "break in" procedure. I traded that car at about 120K miles and some rookie is still driving it. Never had a transmission or rear end issue with the car.

Then again... if I am the one having to pay the repair bill I would probably follow the instructions. Yea, 50mph towing sucks, but damaging a new truck sucks way worse.