rhagfo is right on.
From Eaton - G80 diff. manufacturer:
A new axle can produce excessive temperatures (plus 350 degrees F) due to the ring & pinion breaking in that will break the lube additives down. Avoid high loads, trailer towing and high speed extended driving during the initial break in of the vehicle. After the break in period axle temps will level at a much lower figure. Gear Lube changes are a good idea because the additives are replenished and contaminates such as casting sand are eliminated.
2011 Silverado manual:
Do not tow a trailer at all during the first 800 km (500 miles) the new vehicle is driven. The engine, axle, or other parts could be damaged.
During the first 800 km (500 miles) that a trailer is towed, do not drive over 80 km/h (50 mph) and do not make starts at full throttle. This helps the
engine and other parts of the vehicle wear in at the heavier loads.
2005 Manual (from my last truck - - 2005 3500 SRW Duramax/Allison):
New Vehicle Break-In
Notice: Your vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines:
• Keep your speed at 55 mph (88 km/h) or less for the first 500 miles (805 km).
• Do not drive at any one speed—fast or slow—for the first 500 miles (805 km). Do not make full-throttle starts.
• Avoid making hard stops for the first 200 miles (322 km) or so. During this time your new brake linings are not yet broken in. Hard stops with new linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline every time you get new brake linings.
• Do not tow a trailer during break-in. See Towing a Trailer on page 4-69 for more information.
page 4-69:
Towing a Trailer
Do not tow a trailer during break-in. See New Vehicle Break-In on page 2-21 for more information.
My 2011 - I drove 750 miles before towing. After the first 600 miles of towing I changed the rear diff fluid - milky and gray. Changed again when I installed a PML diff. cover - clean and clear.
My 2005 - I followed the manual and changed the rear diff fluid after 750 miles of towing. Changed the fluid every spring before towing. I had PML diff cover on it too.
2017 Keystone Avalanche 320RS
TV - 2011 Chevy Silverado 3500HD LTZ CCLB Duramax SRW 4X4
