Posted by MoparNorm on Saturday, February 07, 2004 at 11:55PM :
In Reply to: Re: auto transmission posted by MoparNorm on Saturday, February 07, 2004 at 11:48PM :
Re: "500 and 518 Truck transmissions,
These transmissions continued the bulletproof line of the A727, A904, and A999. In essence, they were an A999 transmission (which mixed 904 and 727 specifications) with a lockup torque converter and overdrive planetary gear set.
The gear ratios of these transmissions were matched to the engines, which hurt gas mileage and perceptions of power though it saved some money. Generally, vehicles should be just above their peak torque while at cruising speed, which is generally around 65-75 mph in North America, to provide a good mix of mileage, hill-climbing, and passing acceleration. However, at the time, the corporation decided that money was not available to do this. The effect may not have been too bad. We can infer from trade journals' surveys that the warranty costs were roughly the same as the three-speed A904 and A999 transmissions, and only a little more than the legendary A-727."