Re: 2500 HD rear axle
This is an excerpt from one of the many dieselpage articles about the new HD pickups.
Duramax 6600 The New GM Diesel Trucks -October 1999
"Big power needs a strong rear differential. GM is using a corporation built differential with a 11.5" diameter ring gear and synthetic gear oil in the new Duramax trucks. Earlier 3500 series trucks used a 10.5" differential, and most 2500 series trucks used a 9.5". All Duramax diesel equipped trucks will have just one available axle ratio, 3.73. With an engine torque curve "flat enough to set a glass of water on", the 3.73 axle ratio combines the best attributes of torque multiplication required for heavy-duty towing and higher gearing for "best in class" fuel economy. (Bigley, Jim)"
'85 diesel burban