Whats Medium Duty??

I have a GMC '99 7500. Is that medium duty?

Its got a CAT in it and a Eaton Fuller 9 speed.

Dan, your truck is a true medium duty truck. We have several 7500's here at work with the Cat and Allison trans. We have had very few problems out of them. We use them for our big bucket trucks and digger boom trucks.

generaly there are three classes of trucks,light,medium and heavy.light trucks are 1 ton max accept for some military government spec trucks.anyway medium duty starts at 2 tons or class 4 and ranges to class 8 from there are medium-severe duty and heavy duty wich are usually semi tractors or cement mixers etc.each class is designated and specified by weight range wich factors in axle,suspension and tire load range.other components are specific to power and torque such as drive lines, input, and output shafts in the tranny etc.