purchased by my wife for her horse transport business. Net weight on trailer is 8k, fully loaded is 16k. At how many miles should she swap out the engine oil? What about running synthetics in the diffs? We already have used Transynd in the other truck so we are aware of that. Does the 2011 come with Transynd?

Hooo boyeeee, you are gonna get ten thousand opinions and lots of pushing and shoving between the participants... "Break-in" is the equivalent of religion around here...

First (and foremost) you cannot go wrong by simply following the owners manual to the letter... After all, doing that guarantees your power train for a 100K miles...

Now let me insert my religion, errrr opinion, on this topic having broken in two brand new 2500HD's within the past year...
Try to get a couple hundred miles on the truck before pulling a load (if you can)... This helps the ring and pinion gears to lap themselves into each other... If you cannot do that, then tow slow and pull over for ten minutes every hour or so to let the gear teeth cool down until you get to the magic 500 miles...

On my first HD I was not able to to any slow driving as I picked the truck up in Houston and immediately got on the xway going to Michigan (not towing)... I tried to hold it down to 50 mph but the nutbags on a Saturday morning in Houston were still hung over from Friday night, armed to the teeth, and really hostile... So after 20 miles of being cursed at and given the finger, I was forced to pick it up to 65 to keep from being rear ended, then stomped and shot just to show me they were annoyed...
I stopped at 750 miles and changed oil and filter (Rotella T 15W40)... Truck is at 6K miles and seems perfect... I will be changing the differential lube and the tranny fluid sometime this weekend... I had intended to do it at 5K but I have been busy...

The new truck, just purchased, I managed to get to 240 miles of local driving before having to make an 8 hour round trip pulling 11,000 pounds... We drove 50 mph until 500 miles then 62-64 for the rest of the trip.. It is now at 1600 miles and I am ready to do the first oil change... That will be Rotella T also...

As far as synthetics, I am neutral... I prefer to change my oil/filter more frequently so I use dino dung because for the first 3500-4000 miles there is no difference between the cheapest CJ4 rated dino oil and the most expensive class IV synthetic... That'smy story and I'm sticking to it...

Go read BOB IS THE OIL GUY

cheers...

Denny is right. You know what opinions are like. ;) I personally followed the owner's manual. I hooked up to my trailer with 550 miles on the clock. Prior to that, I varied RPM and speed and gave it quite a few short trips in town to let the gears get some heat and then cool down. I've gone by the manual on all of my Dmaxes without any issues, and this is my 5th one. I'm at 9,900 miles now, and I'm getting ready to do another oil/filter change. I'm also going to change out the external trans filter.

My vote is to go by the manual. GM knows what they're doing. :) There's my $.02.

I would check the diff for fuild. Our truck only had 3 qts in it. We have the locker. We have an 05 but I would still check.
chevman

Follow the owners manual. Maybe I'm kidding myself, but it seems to me that the opinions expressed by GM engineers, in the form of the owners manual, are probably more reliable than any other opinion. Those engineers say you don't have to use any additives, in fact you shouldn't, you don't need to change the oil until the oil monitoring system says to do so, and you SHOULD NOT tow for the first 500 miles.

Follow the owners manual. Maybe I'm kidding myself, but it seems to me that the opinions expressed by GM engineers, in the form of the owners manual, are probably more reliable than any other opinion. Those engineers say you don't have to use any additives, in fact you shouldn't, you don't need to change the oil until the oil monitoring system says to do so, and you SHOULD NOT tow for the first 500 miles.

Nahhh GM engineers are full of $h!t! lol

If anything, I'd check all the fluid levels first to make sure it left the factory with enough. It may take you a few minutes, a ratchet, and couple of shop towels. But at least it will get you familiar with where everything is underneath, and well, maybe the challenges ahead.

Dude - How many threads do you need on the subject.......

http://www.dieselplace.com/forum/showthread.php?t=391828

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