The bearing on the transfer case is loose. I just replaced the transfer case last year. Also I get 460 kilometers per 128 litre tank..I had a complete tune up changed everything..is there any thing else I can do...I bought new tires had 265 75 R16 now have 245 75R16 is this the cause..Help...Thanks John
Transfer case and how to improve mileage on 2001 Chevrolet Silverado 2500 HD
by Tunkwa in Sumas, WA on April 08, 2009
ANSWER by Andy Y on April 08, 2009
Are you sure your transfer case is failing again? That seems awfully soon for a bearing to be failing again. In any case, the 245/75R16 is a shorter tire than the 265/75R16 (essentially a 31" tire vs a 32" tall tire). This will make your engine run at a higher rpm at a given speed than your old (taller) tire. You may have noticed a slight increase in acceleration performance. Tire pressure can also influence gas mileage, maybe the shop set it fairly low for comfort? hope this helps!