Left the front stock - rear went with the PML cover (1 quart over stock cover). Stock fluid is synthetic. I use 75X90 Mobil 1 synthetic gear fluid.
SAE 75W-90 Synthetic Axle Lubricant per the manual. Look for a GL5 rating on the bottle.
Changed the rear end fluid after the first 600 miles of towing and again when I installed the PML cover.
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.
Spare tire - got rid of the steel wheel so I can rotate the spare in when I rotate the tires.
2011 Chevy Silverado 3500HD LTZ CCLB LML SRW 4X4 Blue Granite Metallic.
Towing a 2012 Cruiser Patriot CF335SS fifth wheel.
2005 Chevy Silverado 3500 LT CCLB LLY SRW 4X4 Silver Birch Metallic
2004 GMC Sierra 2500HD SE ECLB LB7 4X4 Sand Beige Metallic
Last edited by NorskeNY; 02-04-2013 at 06:06 PM.